Who can do a pre purchase inspection in Perth?

Post by **Nabstud** » Mon 30 Mar, 2020 10:36 pm

I’ve looked at a 280S and it is in great condition. Checked all the usual rust spots and it is straight as an arrow. He has receipts for lots of maintenance work done and he has kept it in great working order. I have reasonable mechanical knowledge and this car is almost perfect for me - except it’s not a 450!!

Who would you recommend in Perth to get a pre purchase inspection done? All his maintenance work was done at a Mercedes specialist workshop and looking through the receipts points to a great condition car, just replaced seals, hoses etc.

Post by **CraigB** » Tue 31 Mar, 2020 10:20 am

hopefully one of the WA guys sees this soon. Just a suggestion, if it is a reputable Benz place that did the work, I would just call them for starters. Not really any reason for them to lie about the condition of the car - also I would expect them to say "we don't really know the car, just did recent work" or preferably "we have been working on that car for years, really good car etc."

Post by **Nabstud** » Tue 31 Mar, 2020 2:42 pm

Yeah Craig, I did call them and they say they have pretty much just done regular maintenance and nothing majorly wrong. Just found out they also do a pre purchase inspection service so I've answered my own question!

Post by **Nabstud** » Wed 01 Apr, 2020 1:56 pm

I'm getting a pre purchase inspection organised, any other checks I can do? Gonna do a PPSR check, anything else?

I've checked out a couple and this one is the best by far. Totally straight, everything works, even the AC works, nothing is missing, original paint with only a couple stone chips and little marks on it. 2 tiny spots of rust, a smidge of surface rust in the engine bay, nothing in the floors, spare tyre hole is immaculate as are either sides of the boot. If buying just on condition I would have put a deposit down straightaway!

I'm not fixated on any particular model, would like a V8 but the good ones are either far away or out of my budget. This one just presents almost immaculately, may be a while until another one in this condition comes along. It's a nice blue colour with white interior (not sure on the official details), comes with original manuals etc.

It's a 280S, is it worth the $8.5k he's asking? Is there any reason I should wait for a SE or SEL? This one has the carby and manual windows.

As good as it is, I'm happy to pull out if the inspection shows anything I don't like or there is any reason I should be waiting for a SE/SEL.

He has taken the ad down, this is the only pic I have from the ad

Post by **CraigB** » Wed 01 Apr, 2020 2:41 pm

I think people refer to this as the 'poverty pack', but really it is just the windows I think, and I love manual windows and not the electric ones that seem to always eventually warp.

The carby can be a real issue though. The main issue is that the body warps on them and you get air leaks. I suppose they can be rebuilt at a cost, and if this car is running perfectly, maybe it has been done. Maybe it is low mileage. I mean there must have been lots of miles done on these carbies, but they are the one thing that tends to come up as a problem in aged cars. I think it is possible to fit a replacement weber or holley, but you have to make sure you get the right one. I had a 280s with a Holley economaster and it was all wrong, bad running, thirsty and low power - heaps had been spent on the car. I did a straight gas conversion because it was a driver and it worked perfectly.

But the value in this car is the condition, so so hard to find cars in this condition. So I have talked down the car for its spec, but another car would cost more than the purchase price just doing paint. If I was the seller I would stick to my price on a car in this sort of condition and not be in a hurry - it would piss me off if people lowballed me based on he spec and I would tell them go away. Particularly if say you asked 'what's this worth' on facebook I am sure you would get a chorus of responses saying 'tell him he's dreamin' for a 'poverty pack' car.... but then those armchair experts rarely actually put the time into restoring cars and valuing that you just can't replicate a good 'survivor car' .

My main recommendation is to call the PPI people and say "I have heard the solex carbies on these can be a real issue - can you play particular attention to the condition of the carby and how well it is running.

SE/SEL is definitely a better system and doesn't have an real issues, a V8 I think makes a real difference (have you driven one - I happen to have one of each here 280se/450sel) and if you are thinking investment, that can make a difference. But....... its going to be very hard to find a car in this condition full stop, let alone in your budget.

And what is it worth? Couldn't possibly be less than $5k, even for the critics.... how quick can you spend $3.5k on repairs/resto - that's a cheap transmission rebuild. I think the more important question is if you can drive it and not spend money on it and if you later think 'wish I bought a V8'. But if you changed your mind, I think there is always a market for cars in this condition.

Post by **Nabstud** » Wed 01 Apr, 2020 3:30 pm

Thanks Craig, you are pretty much echoing my thoughts, not being a "Benz" guy I'm not super confident in buying a good or bad model. Reading online only helps so much, forums I find is where the info is at. I'm not on Facebook, I steal my missus account for Marketplace but find people are knob ends as a rule! I'm a Ford man at heart but a similar age/condition Ford would be $15-20k easily, and anything that isn't poverty pack or is V8 is $20k+, Not even near my budget.

When I rang to book the inspection the guy mentioned the carby was the only real issue in these cars. It purrs like a kitten at the moment so if I get it I will cross that bridge when I get to it.

Just need to decide if I can effectively pay top dollar for a 6cyl "poverty" spec but in fantastic original condition. I much prefer the V8, test drove one that drove OK but was too rusty for me, but my budget won't stretch to a good condition V8 so it looks to be either a 6cyl or nothing.

Do I wait for a V8 (that may not exist in my budget) or get this one? If I let this one go it will be a while until an equivalent comes up! Decisions, decisions...

Post by **T-Modell** » Wed 01 Apr, 2020 5:17 pm

Hi,
the best car is always the one with the best body. Everything technical can be fixed with lower $$.

Imho with the 280S, you have to say goodbye to performance and low fuel consumption. I remember as a child, my father's W123 280E was in repair and he got a W116 280S for a weekend to replace. His comments were "doesn't pull a sausage off a plate" and the fuel consumption was enormous, especially in regards to the performance.

All this might not be important in Oz, but you should know. The photo looks great, but even with rotten cars all photos look great

Regards
Thomas

Post by **CraigB** » Wed 01 Apr, 2020 5:36 pm

Reading your comments, I think the question is a nice looking car that you probably won't spend a lot of money on vs. waiting for a V8 that will no doubt need money/work which ultimately puts you up in a higher price range. It might be worth some googling to see if people have successfully fitted another carb that works well. If running sweet you wouldn't touch it of course but at least you know what your up for potentially. I imagine much like on a carby W108, fixing their old zeniths or fitting brand new webers works out similar money at $1k, but the result is something that won't be a future problem.

Interesting about Fords, in my early 20's I had an XT fairmont 6cyl, then an XT 302 V8, then a XW 302 fairmont, white with a black interior similar to the GT. My first childhood memories was the families '57 customline and then a '66 Galaxie, so I had that Ford rather than Holden mindset, but looking back I wouldn't swap any of them for the W116 - but I know the market sees it differently. My sisters boyfriend had a red XB GT coupe that I had a soft spot for and he would chuck me the keys sometimes to run to the shops etc, but then I wouldn't swap my AMG 500SEC either. But each to their own!

Post by **Nabstud** » Wed 01 Apr, 2020 7:57 pm

Yeah Thomas, I took it for a short test drive and I reckon my Ford Ranger 4WD with remapped ECU would run rings around it hahaha!!!! The photos in the ad weren't the best, definitely looked better in person which is usually opposite! It will only be a weekend cruiser so fuel consumption isn't a consideration at all. Potentially if the 6cyl blows up I would seriously consider a 350/450 transplant anyway, then I would be 100% happy.....

Craig, your Ford history reminds me of older mates cars back in the days, I was born in 79 so missed out on those cars, my first cars were XC/XD/XF fords before moving onto a manual ED, then 4x4s took over.

I'm confident of sorting any mechanical issues either myself or with a mate's help so the body/interior condition is the main priority. Provided the inspection is good I will go ahead with the purchase.

Everything I've read says they are a solid car with no main issues, any W116 specific issues I need to keep an eye on?

Post by **T-Modell** » Wed 01 Apr, 2020 8:14 pm

I don't think, the M110 would blow up; if that's the case, I'd get the car. If you're not happy with it, you will always get it sold if it is in the state, you described.

Have fun with it
Thomas

Post by **CraigB** » Wed 01 Apr, 2020 8:24 pm

W116 is a really solid, well engineered car. M110 is a very solid engine - the main issue is if they start to blow smoke after running down a hill or on start up, it will be valve seals, which is not that bad, but if guides gone they are a complicated car to remove head - tied up in the cam carrier etc, but if you can work on it yourself, not such an issue. But only at very high mileage is that an issue. Rust, particularly around firewall areas where it is hard to repair - where is your rust spots? Vacuum locks and HVAC can have diaghragms go, but its not that hard to trace and replace. Electric window regs and switches often go, but not your problem. Sunroofs rust and leak etc but guessing that's not a problem either. Leather cracks etc......So there are advantages to your spec! If you get leaks in boot, most commonly tail light seals.

Yes I'm born in 1963.... so showing my age!

Post by **Nabstud** » Wed 01 Apr, 2020 9:45 pm

Its got about 250,000km on the odometer. 2 spots of rust are lower right rear window (where the window trim screw is, can see about a 5c piece size underneath in the boot) and the same on the lower left front window. Can just see it on the outside, but as always its the rust you can't see that is the issue. Will clean it up good and hit it with rust converter before deciding if it needs more substantial work. Didn't notice any in the firewall area, some light surface rust on the inner fender that looks like a good clean and rust convertor should sort it. I touch around the ID plate too.
Auto trans has had some work done too, new seals and something else that I can't remember.
No sunroof to worry about thankfully.
Will have to check the tail light seals.

Thanks for the info, if/when I get it I will start a thread.

Post by **CraigB** » Wed 01 Apr, 2020 10:19 pm

With window related rust, the problem is if it is down under the window rubber and sitting in there. You might be able to feel up from underneath. You might be able to spray something like tectyl that could creep in there and seal it. But if you can lift the rubber enough to feel underneath - not the end of the world to pop windows out and fix it if it is rusted in there. If rubbers are hard and cracked or you have a chipped or scratched windscreen, the glasses are pretty cheap - say about $200. If rear glass is delaminated, that's much more expensive, not even sure if available and lots of used ones are delaminated. None of it 'showstopper' stuff - just doing a 'brain dump' of what i was thinking.

Post by **Nabstud** » Fri 03 Apr, 2020 11:23 pm

It had the inspection today, passed with flying colours. It's still the original paint, no accident repairs, zero rust except the 2 spots already found, compression good in all 6 cylinders, everything works as it should. Only issues are 3 slight oil leaks (weeps really, not dripping). It made my day when the mechanic said you would be struggling to find a better one, his workshop had a couple W114's, a 450SLC and a 60s 2 door so I was pretty excited when he complemented mine. Hopefully picking it up tomorrow arvo...

Post by **T-Modell** » Sat 04 Apr, 2020 12:55 am

Congrats,

that's always the most exiting times, waiting for the good piece. Sleepless nights, to me it always felt like waiting for my birthday as a child.

I got my SL during the times my first marriage went down the drain, so in the evening of the day I bought it, I was sitting in the SL in the garage with a bottle of bubbly

Thomas

Post by **CraigB** » Sat 04 Apr, 2020 10:38 am

That sounds great. Just curious - are any of those weeps from the head? I had a weep between the head and cam carrier (I think from memory) and was a known weak point, later solved with a redesigned gasket. To change it is a huge job and I just didn't have time. So I used some brake clean and then a sealer called blue max (recommended by Brit bike owners for being able to stop them leaking) - I sprinted that car on track and drove as a daily for many years..... never leaked! But just thought i would mention the experience.

Post by **Nabstud** » Sun 05 Apr, 2020 1:55 am

Not from the head thankfully. Rear diff, fuel pump and something at the front on the rocker cover. The guy was quoted about $500 to fix those issues so instead he took it off the price. He was a top guy to buy a car from that's for sure! Anyway, I got it home after driving about 50km, so far the only issue is I believe a faulty viscous fan coupling. On the highway or driving around the suburbs the temp sits on half, as soon as I stop and idle the temp creeps up stopping just below the 3/4 mark. As soon as I drive off it drops down again (today was about 29°C). When I stop the motor the fan spins pretty freely by hand.

Post by **Nabstud** » Sun 05 Apr, 2020 2:33 am

Anyone know where to the the viscous fan part in Australia?

Post by **CraigB** » Sun 05 Apr, 2020 9:50 am

Try ebay - there are a couple of well priced sellers - one is prestige, something. Its the sort of part to buy new unless you have a source that could swap them over or guarantee. Before you do that, one thing you could try (and its not particularly hot at the moment) is to put the a/c on, which should kick in the electric fan. If that pulls it down by having that extra blowing through, then you could be pretty sure. That's how mine works but that may have been modified. There is an electric switch on the head that I think is wired in to bring the fan on at a certain temperature. But either way, if your cooling is down low, your compressor should be clicking out (although you could also pull the wire to its clutch) and then you just have the extra fan. My main reason for saying this is that I have heard a number of times of it being replaced and not making a difference.

Post by **Nabstud** » Sun 05 Apr, 2020 12:13 pm

Cheers, I wasn’t sure if the fan was just for the ac or not. I checked the electric fan and it wasn’t working with the ac, turns out the fuse was stuffed. Replaced it and it works now, will see if that makes a difference.

Post by **Nabstud** » Sun 05 Apr, 2020 6:46 pm

The AC fan seems to make a difference, still gets hotter when stopped after a run but temp gauge doesn't go as high. Bear in mind I've only just got it so I'm not sure if that's normal or just is an issue.

When driving normally the gauge sits through the top hole of the number 8 if that makes sense. Will sit there for 20mins of highway and suburbia driving, and will go back there soon after I start driving again. Should I get a slightly lower temp thermostat?
When stopped for 5 mins after a run this is where the gauge goes to, even a bit higher to a needle width below the 3/4 mark (a bit lower now the AC fan works). Too early to tell but seems to be more heat when the bonnet is lifted so looks like the gauge is working. Worth worrying about?

Post by **T-Modell** » Sun 05 Apr, 2020 7:43 pm

Hi,
imho there's nothing to worry about, as long as it is between 80 and 100. Also don't forget, that this "temp measurement" is a better guess. I use it to have a "trend", but I don't believe the actual numbers.

Regards
Thomas

Post by **CraigB** » Sun 05 Apr, 2020 9:57 pm

I don't want a car to boil, but I definitely don't want it to run cool. They run much better with the thermal efficiency (I think that's what they call it) at higher temp - you want it to heat up as quick as possible and stay there. I had a 280s converted to straight gas, and they run much better at 100 and you could feel it - but that is a bit different. The fitter told me to see if I could get a 100 thermostat, but I seem to recollect there was only one temp available - just made me think of that when you said about getting a cooler one.

Good point from Thomas too, is the temp varying or is the gauge or sender? When you say car heats up after stopping, do you mean after turning motor off? That's normal because engine is still disapating heat without circulating through radiator - eg. if car close to boiling and turn it off, that's when it usually blows.

I agree with Thomas, if it is in that 80 to 100 I wouldn't worry for now and just drive it and see what its doing over time. One possibility not mentioned is a partially blocked radiator - that can be tested - but if your not seeing it get really hot, then i don't think your doing any harm. Main thing is if its hot and say you are doing lots of uphill, you don't want it to pass that tipping point, but i have been doing towing in my 450 on hot days pulling up long steep hills to my place and it can get much much hotter than that and still cool down when it flattens out, never actually boiled it and I suspect that may be an old partially blocked radiator - I don't think it is the viscous coupling because it is getting hot at pace on the hills when plenty blowing through, and yet if not towing it is fine...........I know that's different, but just sharing some thoughts that might help in diagnosis.

Post by **T-Modell** » Sun 05 Apr, 2020 10:07 pm

You can easily check the accuracy of the temp metre, because it's connected to the clock. Take the number the short hand is closest and convert it to 24h mode, in this case 17 hrs. Take it times the number of the small hand (5), so you get 85. Add the number closest to the long hand (10) and add it. So you come to 95, i. e. your temp metre is fully ok. I hope you do appreciate such insider information.

Thomas, with too much time

Post by **Nabstud** » Sun 05 Apr, 2020 11:48 pm

T-Modell wrote: ↑Sun 05 Apr, 2020 10:07 pmYou can easily check the accuracy of the temp metre, because it's connected to the clock. Take the number the short hand is closest and convert it to 24h mode, in this case 17 hrs. Take it times the number of the small hand (5), so you get 85. Add the number closest to the long hand (10) and add it. So you come to 95, i. e. your temp metre is fully ok. I hope you do appreciate such insider information.

Thomas, with too much time

Is this straight from the Mercedes workshop manual???

CraigB wrote: ↑Sun 05 Apr, 2020 9:57 pmGood point from Thomas too, is the temp varying or is the gauge or sender? When you say car heats up after stopping, do you mean after turning motor off? That's normal because engine is still disapating heat without circulating through radiator - eg. if car close to boiling and turn it off, that's when it usually blows.

I agree with Thomas, if it is in that 80 to 100 I wouldn't worry for now and just drive it and see what its doing over time. One possibility not mentioned is a partially blocked radiator - that can be tested - but if your not seeing it get really hot, then i don't think your doing any harm. Main thing is if its hot and say you are doing lots of uphill, you don't want it to pass that tipping point, but i have been doing towing in my 450 on hot days pulling up long steep hills to my place and it can get much much hotter than that and still cool down when it flattens out, never actually boiled it and I suspect that may be an old partially blocked radiator - I don't think it is the viscous coupling because it is getting hot at pace on the hills when plenty blowing through, and yet if not towing it is fine...........I know that's different, but just sharing some thoughts that might help in diagnosis.

All I am describing is while the car is still running ie. when I got to my driveway I let it idle while I was looking at other things and after a couple minutes the temp gauge had risen as shown in the pic. The receipts show that the last service in November 2019 (800km ago) it was given a full service including "replaced bottom radiator hose, bypass hose, heater hose, water pump thermostat hose, transmission cooler hoses, had radiator serviced" along with other stuff so seems like the cooling system has been given the once over. I've checked the fluid level and the the coolant is fresh and full, new "made in Germany" radiator cap too. It doesn't act like its overheating (pinging, certain smells etc), could just be a sender or gauge issue but the fact it runs about half on the gauge whenever I'm driving tells me otherwise, even getting it up to 110-120 for a bit it ran sweet. The only thing that hasn't been done is the viscous fan hub. Radiator shroud looks to be in good condition.

Or it could just be how this car is!! Just whenever I see gauges sitting where they aren't supposed to be, I like to get it sorted asap.

Post by **CraigB** » Mon 06 Apr, 2020 9:42 am

very good - and you could be right on the money with the coupling, just chucking other ideas around. I have bought from this seller before. https://www.gumtree.com.au/s-ad/bossley ... 1157554777

Best thing is the radiator service - not a lot left and that coupling is cheap enough.

Post by **tsharkey** » Mon 06 Apr, 2020 10:25 am

Nabstud wrote: ↑Sun 05 Apr, 2020 11:48 pm All I am describing is while the car is still running ie. when I got to my driveway I let it idle while I was looking at other things and after a couple minutes the temp gauge had risen as shown in the pic.

What happens when the aircon fan is running and you are idling in the driveway - Is the temp where it should be ?

Post by **Nabstud** » Mon 06 Apr, 2020 11:28 am

tsharkey wrote: ↑Mon 06 Apr, 2020 10:25 am
Nabstud wrote: ↑Sun 05 Apr, 2020 11:48 pm All I am describing is while the car is still running ie. when I got to my driveway I let it idle while I was looking at other things and after a couple minutes the temp gauge had risen as shown in the pic.
What happens when the aircon fan is running and you are idling in the driveway - Is the temp where it should be ?

Tried it yesterday and it seems to not go as high but it was only a 10min drive. Gotta take it out tomorrow for a good run so will hopefully test it then.

Post by **Nabstud** » Tue 07 Apr, 2020 5:40 pm

Today has been 33°C and humid, I went for a 20min drive including 10mins of 100kph. Temp stayed at about half the whole time, again when stopped it slowly started to rise. After 15mins I went back home the longer way so lots of traffic lights etc (not a nice easy highway drive) and again the temp stayed at half. I left it idling in the driveway and with AC on and it seems to slow the rise down but it kept rising. I let it idle for 10mins and it slowly crept up to a needle width over the 3/4 mark, I slowly dribbled about 2L of water over the radiator while it was still idling and the gauge soon started to drop almost to the halfway mark. Giving it a little rev also seemed to stop it rising.

I figure if its the radiator it would get hot when the engine was under load. The last service in November shows a $236 charge to services the radiator, can only imagine it was cored/flushed for that price, who knows.

The AC fan doesn't seem very efficient, almost like half the air is coming out from between the fan and AC condenser. When I switched the motor off the fan clutch was still very free. Thermostat seems to be doing its job, I figure if it was faulty it would be stuck closed, stuck open shouldn't cause the issue I'm having.

I've ordered a new fan clutch as that is one of the last items to do. Would a buggered water pump cause this issue?

Post by **Bartman4800** » Tue 07 Apr, 2020 6:18 pm

Instead of looking at the meter, get yourself an infrared thermometer (they are quite cheap)

You say half way, which might be too cold to begin with, telling me that your thermostat is opening too soon.
A temp of around 90 degrees while idling after a run is a fair temperature.

Measure the top hose that comes out of the thermostat housing.
If it was not for the physical distancing you could come around to my place (just north of Rockingham) and use mine.

Unless you have a proper instrument to measure, you are just guessing.

Bart

Post by **Nabstud** » Tue 07 Apr, 2020 8:49 pm

I do have one, went to use it but the bugger seems to be broken!!! New batteries haven't helped....

But I do have a multimeter with temp probe attachment, when the motor cooled down I started it up again and stuck it in the radiator coolant and it showed 82-83°C which was inline with the dash readout so at least the gauge is reading correctly. Can't check it when too hot though.

The bottom radiator hose feels pretty warm so looks like the coolant seems to be flowing well. When the temp is up near 3/4 the radiator hose feels pretty firm too.

Cheers for the offer, I am up near Ballajura so a fair way from you! Like you say maybe that's just how it is, I just wanna make sure I haven't missed anything and everything is operating spot on. I like things to be running right so I tend to get carried away over the small stuff sometimes haha

Post by **CraigB** » Tue 07 Apr, 2020 10:20 pm

I'm glad you have ordered the part - I reckon you could be on the money (and was on it from the start!) but no harm in talking through ideas like we have been doing. Will be keen to hear the result.

Post by **Nabstud** » Wed 08 Apr, 2020 11:45 pm

Well Craig's hunch was right, back to square one. Received the fan clutch today (overnight from Melbourne to Perth, not bad) and installed it, went for a good drive then let it idle in the driveway. Took longer to get hot but it still did. The new fan has much more resistance than the old one and I can feel more air being pushed through but it seems to be sorting the symptoms not the problem. While driving on the highway I was slowing and accelerating hard to load it up and the gauge didn't move from half way.

This time a small amount of coolant came out the overflow (maybe 50mL) and the top hose was hard. While it was still idling I took it for a 5min drive around my suburb and the temp dropped back down to half way. When I pulled up at home I popped the bonnet (while still idling) and the top radiator hose felt cooler and softer. Hmmm...

The only things left are thermostat, water pump and head/head gasket. The fact it doesn't get hot while driving on the highway or suburbs, even on 33°C + temps, says to me its not the head/headgasket. No bubbles in the radiator either.

So far it has had done:

New radiator cap
New coolant hoses
New coolant
New belts
New fan clutch
Radiator serviced

What next? What tests can I do? Short of just putting in a new thermostat and waterpump!

Post by **CraigB** » Thu 09 Apr, 2020 9:21 am

Thinking of its behaviour, its hard for me to imagine how the water pump would change things. Thermostat sticking, but always consistently and same behaviour? - doesn't seem to fit either. Probably same with guage, but if you had an independent gauge you could temporarily fit, that would be an easy test - shame to chase all these problems and have it in the gauge.

OK what about radiator cap - did you change it, is it correct poundage for car also you can test with the right equipment - the right workshop or maybe a radiator place might have one of the testers. New parts can be faulty. Different car but I had a clubman that would be fine most of the time but under pressure would boil. Replaced radiator etc and then I solved it with just a higher poundage radiator cap.

And from afar, thinking of any options - how reliable and how well was the radiator cleaned and checked for flow? But then you could drive yourself nuts thinking everything was done wrong... redo ,... and still have the issue!

But apart from that, its not overheating, its just operating within an acceptable range. I agree that's not normal and most of my cars sit pretty steady, but I don't think it is doing any damage. I would be concerned if it was running too cool and therefore not running efficiently and perhaps carboning things up. Maybe there is a bit of air in there that will work its way out with more use? Any loss in pressure will increase the temp. I think I would just drive it for a while and monitor it...... and keep thinking about it!

Post by **Bartman4800** » Thu 09 Apr, 2020 10:47 am

I would replace the thermostat. Thermostats are wear parts and I have replaced them on most of my 2nd hand cars. They are cheap too.

And - very important - make sure there are no airlocks in the cooling system.
I am not familiar with the M110 engine but my M180 has a tendency to lock air under the thermostat.

If the thermostat does not have a "navel piercing", drill a tiny hole in the rim (inside the O-ring seal) and mount that at the highest point.

Regards, Bart

Post by **tsharkey** » Thu 09 Apr, 2020 12:45 pm

Bartman4800 wrote: ↑Thu 09 Apr, 2020 10:47 am If the thermostat does not have a "navel piercing", drill a tiny hole in the rim (inside the O-ring seal) and mount that at the highest point.

Hi Bart - At the risk of hijacking this into a Thermostat thread, what does piercing the Thermostat do ? I have had all end of trouble with new Thermostats, either being too high (90° instead of 80°) or way to low, (60°C). The only ones that have ever worked correctly out the box for me was a few I bought from John years ago. This is all on multiple OM617s and they do like to get an airlock which I have to bleed out.

Post by **Bartman4800** » Thu 09 Apr, 2020 12:54 pm

So if you drill a little hole (1 mm is enough) in the rim around the valve, but inside the O-ring seal area, you allow a tiny bit of flow, even when the thermostat is closed. If there is any air locked underneath a closed thermostat, it can disappear through the tiny hole.
Warm up time on a cold engine could be marginally longer, but I cannot tell the difference.

Most new thermostats already have, what looks like a navel piercing. It is a tiny valve that does just what I described above.

maxresdefault.jpg

And really modern cars actually have the thermostat in the return line (between radiator bottom hose and engine). In that case the highest point is the expansion vessel, which eliminates the risk of an airlock.

The differences in temperature you describe above, I can only explain in poor manufacturing quality. A bit of luck seems to be involved.

Bart

Post by **Nabstud** » Fri 10 Apr, 2020 4:05 pm

I've ordered a water pump and thermostat, I'll make sure it has a hole in it before install.

Post by **kimrh** » Fri 10 Apr, 2020 4:57 pm

How old is the radiator (does it have a date stamp on it?)
Often symptons like this of fluctuating heat (cooler when driving & heats up during traffic or idling parked up) is a radiator that is only half working because the bottom tubes are clogged up with gunk over the years and only the top half works.
Not saying this is the issue here - but besides a failed thermostat or leaking water pump seal - it can often be the radiator itself that is the culprit and it needs replacing.
Go and see the guys at Natrad Malaga or whatever outlet is near you and get a quote on a new one of their radiators to fit your Merc
Their modern design cores/fins are far more effecient than the older designs and also peace of mind in hot weather/suburban traffic
By they way - MB Star Motors in Balcatta are recommended for working on the old Benz models as you were asking earlier in the thread
https://www.mbstarmotors.com.au

Post by **CraigB** » Fri 10 Apr, 2020 9:16 pm

Hi Kim - I think it is stated above there is a receipt for over $300 for recent work on the radiator (I took it that was just the radiator and not fitting) - and for that sort of money you would expect top and bottom tanks opened and rodding. A proper old school radiator in a W116. Still, I had similar thoughts. Perhaps its worth asking exactly what was done to the radiator..... the radiator place wouldn't see that many 'old' radiators. Its just that concern that it was given to the apprentice or something like that, but they can test the flow.

Post by **Nabstud** » Fri 10 Apr, 2020 10:25 pm

Yeah the radiator has been "serviced", well it at least has new black paint on it!

Got my temp gun working today so I did some tests. Was 34°C here today and I first started driving at 3pm so right at the hottest part of the day.
Took it for a 10 min drive around the suburbs speeds less than 70kph and lots of stops and starts. Drove fine, gauge sat approx half way.
Got home and let it idle and temps increased a little as expected.
So I went and took it for a 15 min drive up and down the highway. I wasn't shy and put my foot down hard to accelerate up to the 100kph limit, then giving it a squirt to 120kph every now and then. Tried to keep it under load until I got home.
I popped the bonnet and checked the temps for the next 15mins and they went up quickly as expected but stayed there for the next 10 mins. So far the cooling system is working perfectly. Gauge never went past 3/4 mark. Note that the bonnet was up for all this time.
While it was still idling I shut the bonnet then packed my stuff away. After 2/3 mins I noticed coolant was dribbling out the overflow. I checked the gauge and it was a few mm above the 3/4 mark. Checked temps again and they had quickly gone up. Had to sort out the kids so that's where the testing ended.

I put it all on a table (see below), none of the temps were too high until I shut the bonnet, even then nothing too bad. Main concern is how quick it rose, the top hose was super hard and it felt noticeably hotter where the bonnet latches are. It may still be within MB spec but something is not sitting right with me.

The dashboard temp gauge is pretty accurate from 80 mark to the 3/4 mark (which happens to be about 95°C).

Sounds like the new German radiator cap may need to be changed, it has 120 marked on top of it.

Any other ideas? It all seems to be pointing to airflow but I thought a new fan clutch would sort that, I shone a torch through the radiator and I could see some light through the AC condenser. Revving the motor to 2-2500rpm for a minute brought the temp gauge down to the 3/4 mark.

Post by **Nabstud** » Fri 10 Apr, 2020 10:42 pm

Not sure about a date stamp, all I could find was this stamp on the top just behind the radiator shroud:

116 501 10 01
REHR C567

I'll check out Natrad and my normal radiator guy and see what they have.

Post by **CraigB** » Fri 10 Apr, 2020 11:35 pm

My thinking, in case it helps, is to go to your normal radiator guy, esp if you know and trust him. I am sure he can check the pressure of your radiator cap and can possibly flow test the radiator in situ.

But I tried to google the correct radiator cap and came up with this thread that suggests you should be running a 100 and not a 120 - but if that's the case, you have plenty of pressure in the 120 even if it is a bit weak. I'm not sure best way to check what it should have - I don't think i have a manual for it.

https://forum.w116.org/mechanicals/radiator-caps!!/

I'm doing this from an armchair, so just guessing, but the airflow thing I think would be explained by a partially blocked radiator - just that only part is trying to dissipate the heat and and with plenty of air around it, can keep up - similarly the revs and blowing more air over it.

How about pointing your thermometer to different tubes of the radiator - may find cool and hot tubes?

Post by **Nabstud** » Fri 10 Apr, 2020 11:42 pm

CraigB wrote: ↑Fri 10 Apr, 2020 11:35 pm My thinking, in case it helps, is to go to your normal radiator guy, esp if you know and trust him. I am sure he can check the pressure of your radiator cap and can possibly flow test the radiator in situ.

But I tried to google the correct radiator cap and came up with this thread that suggests you should be running a 100 and not a 120 - but if that's the case, you have plenty of pressure in the 120 even if it is a bit weak. I'm not sure best way to check what it should have - I don't think i have a manual for it.

https://forum.w116.org/mechanicals/radiator-caps!!/

I'm doing this from an armchair, so just guessing, but the airflow thing I think would be explained by a partially blocked radiator - just that only part is trying to dissipate the heat and and with plenty of air around it, can keep up - similarly the revs and blowing more air over it.

How about pointing your thermometer to different tubes of the radiator - may find cool and hot tubes?

Yeah its looking more like the radiator, once the bonnet is shut the only air that can enter is through the radiator.

I just bought a Tridon radiator cap for $9 just to see if that makes a difference.

Post by **kimrh** » Sat 11 Apr, 2020 1:17 pm

My Bet is on the radiator not working 100%
But yes by all means swap in another cap first
Those viscous fans pull a lot of air (better than electric fans) so the temp should not go up when parked

Post by **Nabstud** » Sat 11 Apr, 2020 5:59 pm

Well it was bloody hot here today (38°C), I took a 30min round trip (no highway, just suburb roads, lots of stop start) to Repco to get a new radiator cap. Had the AC on there and back, the car sat on just over 1/2 on the gauge.

When I got home I left the AC on and let it idle in the driveway. As expected the temp gauge rose slowly for 5mins to a bit about the 3/4 mark and a couple of drops came out the overflow. I then revved the motor to 2000-2500rpm and held it there for a couple of mins. The temp gauge slowly came back down to below the 3/4 mark. I've read elsewhere that this is how to test the water pump, my mind still can't work that one out...

Surely in this heat with AC on and running at higher revs while stationary the car would get hotter if the radiator was stuffed?

Post by **CraigB** » Sun 12 Apr, 2020 12:31 am

firstly, I don't know and just chucking ideas around - but my explanation for the partial block radiator, is that while its pulling revs, water circulating, air going through it etc, and lets say only half the tubes flowing on radiator, that is still enough to have enough cooling effect. Then you stop and idle, water pump circulating water slower, moving through radiator slower and perhaps less air circulating to cool that radiator (fits the bonnet open example), and there is not enough water circulating and dissipating heat from motor to coolant to radiator to air.... then you rev it, water pumped around, air moving.

But as mentioned, you have the perfect tool to test that - did you try pointing your temp gun at various parts of the radiator as suggested? It could I suppose be uniformly blocked, but I think when bad, often whole tubes block completely. As it moves from hotter to cooler, where is the heat relative radiator to block and what cools down first? Temp sender is in head.

Post by **Nabstud** » Sun 12 Apr, 2020 7:12 pm

Today I checked the temps at various spots on the radiator. high 80s at the top, low 80s at the bottom, I couldn't find any hot or cold spots so seems like its doing it's job I didn't check every tube as the fan, shroud and AC condenser made access tricky.

I replaced the radiator cap with the Tridon CA1390 (apparently the correct one for my car), didn't make any difference except that coolant started coming out the overflow a bit earlier (3/4 mark instead of a couple mm above 3/4). When compared side by side, the Tridon has a noticeably softer spring.

Thermostat and water pump are in the post, I will hopefully change them this week then at least all the parts are new.

Post by **Nabstud** » Wed 22 Apr, 2020 9:51 pm

Haven't had time to install the water pump and thermostat yet. Went for a good hour drive today to pickup some work stuff, ambient temp 25°C and overcast. Mainly stop/start driving with a quick blast down the highway on the way home, got home and she idled for 20mins with the temp gauge only getting up to 2/3s, no coolant loss. Maybe there was an air lock, maybe that's the way it is or just the hot weather was a bit too much for the old duck. I even gave it an "italian tune up", foot to the floor from 0kph to 135kph and it was rock solid and smooth. I'll still change the water pump and thermostat as I have them and then the cooling system will be all done, just gotta wait until summer to test it out...

Post by **Nabstud** » Fri 15 May, 2020 8:00 pm

Went for a 45km drive, mainly highway, 20°C ambient temp. Water pump has been replaced, thermostat been replaced, flushed out the cooling system and new coolant installed. Again while driving and short idling in traffic the gauge barely moved. This is where it sits not with the new 87°C thermostat.

I got home and let it idle for 20mins. Temp gauge slowly rose, this time to the highest I've seen it. Only 2 drops came out of the overflow (maybe settling after the coolant flush). Infrared temp gun said 91°C at the bottom of the radiator and 101° at the top. If I revved the motor to 1500-2000rpm, within a minute the tempo gauge was back at the 3/4 mark. The electric fan never came on even though I measured 103°C at the switch. Earthing out that switch wire turns the fan on so maybe the switch is buggered, may test it in some boiling water.