Poor compression test results

1973-1980 : 280S, 280SE, 280SEL, 300SD, 350SE, 350SEL, 450SE, 450SEL, 450SEL 6.9
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Vanguard
E Class
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Joined: Sat 14 Nov, 2015 6:25 pm
Model you own: w116
Location: Lockyer Valley, Queensland, Australia

Poor compression test results

Post by Vanguard » Mon 14 Dec, 2015 8:38 pm

In my quest to buy a w116, I had a compression test done on a candidate 280se with some varied results:

1 130
2 90
3 125
4 110
5 140
6 110

The test drive by the mechanic said it drives fine, a slight rough idle when warming up, but at low and high speed it responds very well and doesn't blow smoke. While he said it was nearing the need for some work on the engine, he also said that sometimes engines with wobbly results can keep on driving for years.

My question is, has anyone else had that kind of variance or low figures and had their m110 keep on plugging away? I'd like to get a year out of it before spending on the engine, but I guess that's a risky prospect! :pray:
Chris
1984 W123 230E "Gunther"

CraigB
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Re: Poor compression test results

Post by CraigB » Mon 14 Dec, 2015 10:02 pm

Did he do any tests to try and determine if rings or valves or leak down test? Also do you know any history of the car, has it been sitting around? If it has then i guess there is some possibility of valves settling in or you could try upper cylinder lube to try and loosen clogged rings etc that could be causing it. I have heard of this sort of thing working before and with a bit of an 'italian tune up' (ie. a good thrashing!) Certainly i agree that if it drives ok as is that it could last for many years, although if say it was a broken ring, that can happen when cars that are unused for many years get fired up, and i imagine that could go backwards a lot faster. Usually if compression is uneven if you put a few squirts of oil down the spark plug hole and try again, it temporarily seals up worn and will increase compression, which suggests then that valves are the problem. Also valve clearances should be checked, but i doubt that is it. But as discussed other places on here, to take that head off is a time consuming and therefore expensive job. Then again, depending on asking price, you can factor that risk in and be prepared to 'quit out' and wreck the car or replace whole engine if it ends up being a problem. But there is some chance i reckon that a decent run could greatly improve it but it is a risk.
Craig Baulderstone
Lurch
280s's
280SE3.5
280SL
350SL
500SEC's
560SEL's

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Lance
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Re: Poor compression test results

Post by Lance » Mon 14 Dec, 2015 10:22 pm

Walk away.
Regards,
Lance Smart

W114 280E 5 speed manual
W123 280E

Vanguard
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Model you own: w116
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Re: Poor compression test results

Post by Vanguard » Mon 14 Dec, 2015 11:13 pm

He didn't do a leak down test but he recommended a valve clearance/tappet adjustment. The car hasn't been sitting around, but it was probably being used once or twice a week for short runs for the past three years. The battery was replaced recently, which suggests very short runs. The guy was always using the right fluids etc. He got everything from MB.

I've thrown a low offer in, as it sounds like there are some issues with the SLS too. The body is pretty clean of rust... only one door seems to have suffered, with chips along the edge that have surface rust, and a small hole under the trip at the bottom. That's no big deal though. The interior and paint etc look good for the price. Needs a new air con compressor etc. though.

The mech said he thought it was good buying even with the poor motor, as long as I had some money spare for the spare motor or a rebuild down the track.
Chris
1984 W123 230E "Gunther"

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AMG
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Re: Poor compression test results

Post by AMG » Tue 15 Dec, 2015 12:09 am

Lance wrote:Walk away.
agreed. unless it's free.

its a 116. no shortage of them around.
Current:
1987 560SL 4sp. auto Signalrot "Stella"
1987 190E 2.3-16 5sp. man. Blauschwarz "Hermann"
1992 300CE-24 6sp. man. Perlblau / Iceblau "Gretel"
1992 Range Rover Vogue SE 4sp auto Ardenne Green "Oswald"
2012 Renault Sport Megane RS265 Trophy 8:08 6 sp. man. Liquid Yellow "Jean Rédélé"
Previous:
1986 560SEL Anthracitgrau "Schultz" - In Mercedes Heaven
1987 190E 2.6 4sp. auto Signalrot "Sabine" - which now resides/owns Andrew M's Garage
1972 350SLC Astralsilber "Lurch" - now in the loving care of Craig B
1989 2.5-16 Blauschwarz 4sp. auto (parted) formerly owned by Derek/Hasan.

CraigB
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Re: Poor compression test results

Post by CraigB » Tue 15 Dec, 2015 8:53 am

I don't know how common rust free 116's are and interiors are not cheap or easy either. But I think it comes down to how much you can do yourself and likelihood and expense of finding parts. I think the going rate for engine rebuild is something like $8k, head will be $1k to machine and at least that to have removed and fitted. I don't know how well you know your mechanic but I am sure it is no skin of his nose if you put all that labour for rebuilds his way! I think these cars are at the stage where you buy one and then another to get an interior out of etc. etc.

I don't know what your offer was but looking at it from another angle, I have booked less than a weeks accommodation for the family and by the time we have a few spending dollars it will be way over $2k - and i am sure you can think of plenty of ways to easily blow $2k - how much when you take the family out to dinner? So if you spend that sort of money, you get to know the model and the car, have some fun but don't get attached to it and when it breaks or runs too rough either get it towed away for free or sell it to someone here for a few hundred to get interior etc out of? I can think of worse ways to spend $2k..... council rates.... etc.... but that's not optional.

It will always be cheaper in the long run to pay good money to get a spot on car, but you have to be able to recognise that car and not something tarted up, and once you have owned any example for a while you will get to know then model.

I think most people think of cars like they are adopting a child and then committed to look after them, when really it could be more like a one night stand which can be fun - but the long term relationship is always the most rewarding..... but amongst all these anthropocentric examples, don't forget it is just a car!
Craig Baulderstone
Lurch
280s's
280SE3.5
280SL
350SL
500SEC's
560SEL's

Vanguard
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Model you own: w116
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Re: Poor compression test results

Post by Vanguard » Tue 15 Dec, 2015 9:31 pm

hi guys, I've walked away... we'll see what I find next :think:
Chris
1984 W123 230E "Gunther"

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Re: Poor compression test results

Post by CraigB » Tue 15 Dec, 2015 10:43 pm

What about the 450 that has just come up for sale on here. I haven't owned one but i believe fuel economy between the v8 and 6 is not as much as you might expect - one has to work a lot harder pulling the weight around.
Craig Baulderstone
Lurch
280s's
280SE3.5
280SL
350SL
500SEC's
560SEL's

Vanguard
E Class
Posts: 64
Joined: Sat 14 Nov, 2015 6:25 pm
Model you own: w116
Location: Lockyer Valley, Queensland, Australia

Re: Poor compression test results

Post by Vanguard » Wed 16 Dec, 2015 11:22 am

Hi Craig,

The budget doesn't extend that far unfortunately.
Chris
1984 W123 230E "Gunther"

CraigB
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Re: Poor compression test results

Post by CraigB » Wed 16 Dec, 2015 1:54 pm

I am sure you know this, and not saying in a condescending way, because you are doing it right and getting the checks - more perhaps for others that may read the thread, but if on a tight budget you have to be so careful with these cars and be prepared to burn what you have invested eg. my comments about buy a cheapie and run it for a bit. I don't know that 450 or the seller, but if that is a pampered from new car, all working, nothing to do, it would be a bargain compared to most cars for sale. You would be lucky to get a decent paint job for $8k or engine build, probably 3k in a trans, A/c probs usually at least 1k and same for brakes, fitted shocks best part of 1k, alternator, starter, suspension and steering bushes, fuel distributor etc. - and so rapidly of course a 2k car becomes really expensive and the problem is also knowing when to pull the pin, because a car with a blown trans that has new shocks, brakes etc is still a car with a blown trans that nobody wants. And then do you quit out or just spend another 3k and then surely nothing else will go wrong! And that is not to say just because somebody asks $8k that it is automatically a good car, plenty of us have found that, but i think those well cared for cars, everything fixed when it needs it and serviced have incredible longevity but it is so hard to find one usually. And then everyone will say 'thats way too much for a....." but if you do the 5 yr test of how much does this car cost me in 5 yrs, they are usually the cheapest.
Craig Baulderstone
Lurch
280s's
280SE3.5
280SL
350SL
500SEC's
560SEL's

Vanguard
E Class
Posts: 64
Joined: Sat 14 Nov, 2015 6:25 pm
Model you own: w116
Location: Lockyer Valley, Queensland, Australia

Re: Poor compression test results

Post by Vanguard » Wed 16 Dec, 2015 5:53 pm

Yes, understand that whole equation. It all ends up a risk either way, because even the most thorough checks can't really tell if a trans or engine will fail 10,000kms from when it's checked, if there are few symptoms.

Unfortunately I have to take the "buy cheap and spend along the way" path. I am spending my MB budget on a HD clutch for my Landcruiser next week, so there's not much spare coin for this little project. Ultimately if something big breaks, I park it, use my other car until I can afford a fix, if I think it's worth while. At $2k, if I get 6 months or a year out of it initially, I would be more than happy. In fact, if I have to spend $2k every 6 months on improving or fixing it, that's a reasonable little budget for me to work with I think.

Let's just hope whatever I end up with, I don't break down on the way home!!
Chris
1984 W123 230E "Gunther"

Vanguard
E Class
Posts: 64
Joined: Sat 14 Nov, 2015 6:25 pm
Model you own: w116
Location: Lockyer Valley, Queensland, Australia

Re: Poor compression test results

Post by Vanguard » Thu 17 Dec, 2015 10:51 pm

looks like I found one, picking up Sunday, but I'll have to move it over to the w123 section :occasion5:
Chris
1984 W123 230E "Gunther"

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