OM352A Cold Starting

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iank
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OM352A Cold Starting

Post by iank » Wed 19 Aug, 2015 2:51 pm

Hi again folks,

I have been absent from OzBenz for a while, but I am back with another (possibly dopey) question regarding my LA 911 A ex army fire truck. Does the OM352 have any "special" cold starting procedure? Over the year and a half I have owned this truck I have never had much trouble starting it - usually cranks over for perhaps 30 secs (?) then fires up. This winter (and it has been very cold here cf normal) I am having to crank it much longer before it eventually "struggles" into life.
Giving this some thought, I have realized I don't know of any "Cold Start" switch, etc. or even if there is a specified procedure.

Can any of you knowledgeable crew please give me any leads on this?

Ian K :dontknow:
iank
1971 350SL
1980 LA911

"Keep enjoying the Journey"
:joker: :coffee2:

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Tony From West Oz
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Re: OM352A Cold Starting

Post by Tony From West Oz » Wed 19 Aug, 2015 3:52 pm

It is odds - on that it has glow plugs.
There should be a lamp on the instrument panel which indicates that the Glow plugs are working, or if there is one or more not working.

If it is a pre 1980 diesel engine, it is likely to have series GPs. This can be identified by the "wiggle wires" (resistance wire) between the GPs, which are wired in series. Any one of the GPs or wiggle wires breaking, or a fuse or wire connection breaking, will mean that no GPs work.

If it is a post 1980 diesel engine, it most likely will have parallel wired GPs. With each GP having a separate wire to the GP relay box. In this case, is one GP blows, you still have the other ones working. Starting may not even be harder, but lose 2 or 3 GPs and you will know the difference. IF the GP relay or its fuse blow, no GPs will work.

I hope this helps,
Tony
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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iank
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Posts: 64
Joined: Mon 25 Feb, 2008 6:34 am
Model you own: w107
Location: Central Victoria

Re: OM352A Cold Starting

Post by iank » Wed 19 Aug, 2015 5:32 pm

Many thanks for your reply, Tony. I do appreciate it. Your explanation about glow plugs is very helpful, and very clear. What I need to do now is get under the bonnet and have a good look. I obviously need to check for that GP lamp on the dash, and perhaps some kind of switch function that might turn them on/off.

I'll do my "homework" in the next day or two, and report back here.

Thanks again, Ian K
iank
1971 350SL
1980 LA911

"Keep enjoying the Journey"
:joker: :coffee2:

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Tony From West Oz
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Re: OM352A Cold Starting

Post by Tony From West Oz » Wed 19 Aug, 2015 7:47 pm

The GP lamp is usually an inverted "Lavalife" logo.
This is usually activated by the ignition switch, although very early vehicles had what we lovingly call the "Gorilla Knob" to control the GPs.
Look at the RHS of the engine head (passenger side) below the injectors, as this is the location of the GPs on the non-common rail MB diesels. If you have a test light for 12v, try using it between the last GP and ground. This should light up when the ignition is turned to the Run position. If this works then you have voltage getting to that GP. If not you have another issue: - fuse, GP relay, Ignition switch or wiring.

Enjoy,
Tony
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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iank
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Posts: 64
Joined: Mon 25 Feb, 2008 6:34 am
Model you own: w107
Location: Central Victoria

Re: OM352A Cold Starting

Post by iank » Thu 20 Aug, 2015 2:37 pm

Well Tony, once again thanks for you interest and help, but unfortunately we are "singing from different hymn books"! Firstly my OM352A engine (oh btw the truck is a 1980 model) has the exhaust manifold, exhaust brake actuator, turbo, etc on the LHS (ie passenger side in Australia) of the engine/vehicle. (ie on your right when standing on the front bumper looking into the engine bay.) Thus the injectors are along the RHS of the engine, and there is no sign at all of any glow plugs, or wiring going to them.

I have also re-convinced myself that there are no "unknown" lamps or switches on the dash. In fact it may "ring a bell" with you, that the "ignition switch" has a very strange key-like device that plugs into the switch device on the dash. When pushed "home" the "key" turns-on the ignition (only 1 action possible -ie IN = ON, OUT = OFF). The "key" may also be turned clockwise, which brings the park, then head lamps on. To operate the "Starter", after having pushed the "key" IN, there is a simple, separate, momentary action, push button switch on the dash. Operation of this cranks the engine - which starts pretty quickly during warmer weather, but takes quite a bit longer during this time of the year, here in cold old Victoria.

So, you can see I am still scratching my head. It really does appear that there is NO cold starting mechanism. Maybe another member who has owned/operated one of these "L" model trucks (911, 1418, 1923, etc) may be able to add to our knowledge?

Cheers, Ian K :think:
iank
1971 350SL
1980 LA911

"Keep enjoying the Journey"
:joker: :coffee2:

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Bartman4800
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Re: OM352A Cold Starting

Post by Bartman4800 » Fri 21 Aug, 2015 12:34 pm

Looks to me that the OM352 is direct injected diesel without a pre-glow setup, like most trucks.
The a version has an added turbo

Your poor starting might come from another source: clogged up injectors, blocked air filter, poor compression, valve clearance not set properly....

30 seconds is already quite a long starting time, and puts a lot of strain on starter motor and battery.

Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

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Tony From West Oz
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Re: OM352A Cold Starting

Post by Tony From West Oz » Fri 21 Aug, 2015 3:47 pm

I just had a google of the OM352.
Here is the Wiki page on the engine:
https://en.wikipedia.org/wiki/Mercedes- ... 52_engine
Yes,
Direct Injection.
So, that brings us down to fuel (including timing), ignition & breathing (check the air cleaner and exhaust if power when running is down on previous levels).
From easiest and cheapest to hardest and most expensive to remedy.

Breathing - if the engine has normal power and revs to 3K with no problem, then poor breathing would not stop it from starting.

Fuel (injectors). - If you get the engine running, you can use a garden sprayer to mist water into the inlet manifold with the engine doing >1K RPM. You need to put at least 5 litres of water mist through the engine. I have had good results with this method on OM6xx series engines in improving cold starting ans rough idle issues. Otherwise remove injectors and have them cleaned and tested.

Compression - While the injectors are out, check the engine compression. You should have in excess of 300bar on each cylinder (the higher the better and should be even across cylinders - +/- 20Bar variation between cyl. is OK)

Your learning experience continues . . . . . . .



Tony
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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Bartman4800
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Posts: 1905
Joined: Fri 10 Oct, 2008 12:10 am
Model you own: w111
Location: Perth WA

Re: OM352A Cold Starting

Post by Bartman4800 » Fri 21 Aug, 2015 7:20 pm

Tony From West Oz wrote:I just had a google of the OM352.
Here is the Wiki page on the engine:
https://en.wikipedia.org/wiki/Mercedes- ... 52_engine
Yes,
Direct Injection.
So, that brings us down to fuel (including timing), ignition & breathing (check the air cleaner and exhaust if power when running is down on previous levels).
From easiest and cheapest to hardest and most expensive to remedy.



Compression - While the injectors are out, check the engine compression. You should have in excess of 300bar on each cylinder (the higher the better and should be even across cylinders - +/- 20Bar variation between cyl. is OK)


Tony
I think you mean 300 psi instead of bar...

wiki says: Compression at starting speed is 22 bar up to 24 bar (2.2 to 2.4 MPa), minimum 20 bar (20 bar equals 290 psi)

But you can read it here yourself: https://en.wikipedia.org/wiki/Mercedes- ... 352_engine

I would check the valve clearance first, and take it from there.


Regards, Bar(t)
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

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Tony From West Oz
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Re: OM352A Cold Starting

Post by Tony From West Oz » Fri 21 Aug, 2015 9:55 pm

Mia Culpa.
You are correct, 300psi and +/- 20 psi max between cylinders.

Tony
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

User avatar
iank
E Class
Posts: 64
Joined: Mon 25 Feb, 2008 6:34 am
Model you own: w107
Location: Central Victoria

Re: OM352A Cold Starting

Post by iank » Mon 24 Aug, 2015 11:53 am

Once again, thanks guys for your informed, helpful comments here. You may recall that I originated this thread really to satisfy myself that my truck did not have a specific cold start procedure. With your help, I have certainly achieved that. I do not intend to go any further at this stage in attempting to make it any easier/quicker to start. I have found with fully charged batteries, some warmer weather, and a start about once a week (or more) it is starting much better - less than 10 sec crank. So for now I will leave "well enough alone"!!

Thanks again, Iank
iank
1971 350SL
1980 LA911

"Keep enjoying the Journey"
:joker: :coffee2:

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Bartman4800
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Joined: Fri 10 Oct, 2008 12:10 am
Model you own: w111
Location: Perth WA

Re: OM352A Cold Starting

Post by Bartman4800 » Mon 24 Aug, 2015 12:37 pm

iank wrote:Once again, thanks guys for your informed, helpful comments here. You may recall that I originated this thread really to satisfy myself that my truck did not have a specific cold start procedure. With your help, I have certainly achieved that. I do not intend to go any further at this stage in attempting to make it any easier/quicker to start. I have found with fully charged batteries, some warmer weather, and a start about once a week (or more) it is starting much better - less than 10 sec crank. So for now I will leave "well enough alone"!!

Thanks again, Iank
I understand your "don't fix what aint' broken" approach.

However it should start on first push each time (providing you do not have a tiny leak in your fuel line that fills up with air when engine is not running and makes it harder to start) no matter whether it stood for a day or a month.
A valve clearance check has never hurt any engine. If they are too tight you might burn a valve and then you are further from home...
Too loose (within reason) just makes it more noisy.

Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

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Ralph
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Joined: Fri 22 Jul, 2016 6:56 pm
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Re: OM352A Cold Starting

Post by Ralph » Fri 22 Jul, 2016 7:28 pm

iank wrote:Hi again folks,

I have been absent from OzBenz for a while, but I am back with another (possibly dopey) question regarding my LA 911 A ex army fire truck. Does the OM352 have any "special" cold starting procedure? Over the year and a half I have owned this truck I have never had much trouble starting it - usually cranks over for perhaps 30 secs (?) then fires up. This winter (and it has been very cold here cf normal) I am having to crank it much longer before it eventually "struggles" into life.
Giving this some thought, I have realized I don't know of any "Cold Start" switch, etc. or even if there is a specified procedure.

Can any of you knowledgeable crew please give me any leads on this?

Ian K :dontknow:
Hi lank
Newbie just joined. I have an om352a in my bus and found a short squirt of Aerostart in cold weather starts in a couple of turns. No glow plugs. Hope this helps, regards

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Bartman4800
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Joined: Fri 10 Oct, 2008 12:10 am
Model you own: w111
Location: Perth WA

Re: OM352A Cold Starting

Post by Bartman4800 » Fri 29 Jul, 2016 2:00 pm

Yes Aerostart or Start ya Bastard will help your diesel start more easily.

HOWEVER!

This stuff is a very fast solvent. It removes whatever lubrication is still left on your cylinder walls.

In old diesel land using this horse treatment is called HEROIN.

It will start with it but after a while it will never start without it....



Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

User avatar
Tony From West Oz
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Posts: 3222
Joined: Mon 20 Jun, 2005 9:04 pm
Model you own: w202
Location: Bedfordale WA

Re: OM352A Cold Starting

Post by Tony From West Oz » Fri 29 Jul, 2016 6:24 pm

Bartman4800 wrote:Yes Aerostart or Start ya Bastard will help your diesel start more easily.

HOWEVER!

This stuff is a very fast solvent. It removes whatever lubrication is still left on your cylinder walls.

In old diesel land using this horse treatment is called HEROIN.

It will start with it but after a while it will never start without it....

Bart
Agreed!
However a more engine friendly starting aid is WD40. It lubricates the surfaces it contacts and works well as a starting aid.
I have run a diesel engine for quite a few minutes on WD40 simply sprayed into the inlet manifold, when I had an Injector pump problem on a Mazda diesel.
Tony
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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