Brainstorming high oil consumption on OM642
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From: V E G A S
1922 Ford Model T / no OBD
Brainstorming high oil consumption on OM642
The story is
-my lovely 2008 E320 Bluetec suck some water when crossing the puddle and bend the rod at 180k miles
- I bought "rebuild" engine from UK and install it in the car.
The seller informed me that the engine had heads rebuild, as he knew the engine and figured out the lower parts are in perfect condition.
After installation, the "new" engine start pretty fast, but when I run smooth test - cylinder 1 show 12 rpm difference, where 7 is acceptable.
But the engine performs relatively well - good HP (have to watch my pedal push to not enter freeway ramp sideway) although it shows heavy vibration at idle. MM were 20k miles old, so I assumed the vibration has to come from the engine.
I am stuck with this engine and since it pulls well, the idle vibration is secondary issue, but engine uses lot of oil.
I drove it for less than 2000 miles since replacement and it had small leak that I fixed, but even after fixing the leak the low oil warning come after about 500 miles.
Meaning the engine burns +- 1l of oil for 500 miles.
My conclusion is that cylinder 1 has bad rings and that makes for difference in rpm and high oil consumption, but never had such issue on MB and its been long time since I had such issue on other brands.
Anybody has better explanation and possible solutions?
I read the Restore is making "miracle in the pills" that suppose to help with such issues, but never tried it in my life.
-my lovely 2008 E320 Bluetec suck some water when crossing the puddle and bend the rod at 180k miles
- I bought "rebuild" engine from UK and install it in the car.
The seller informed me that the engine had heads rebuild, as he knew the engine and figured out the lower parts are in perfect condition.
After installation, the "new" engine start pretty fast, but when I run smooth test - cylinder 1 show 12 rpm difference, where 7 is acceptable.
But the engine performs relatively well - good HP (have to watch my pedal push to not enter freeway ramp sideway) although it shows heavy vibration at idle. MM were 20k miles old, so I assumed the vibration has to come from the engine.
I am stuck with this engine and since it pulls well, the idle vibration is secondary issue, but engine uses lot of oil.
I drove it for less than 2000 miles since replacement and it had small leak that I fixed, but even after fixing the leak the low oil warning come after about 500 miles.
Meaning the engine burns +- 1l of oil for 500 miles.
My conclusion is that cylinder 1 has bad rings and that makes for difference in rpm and high oil consumption, but never had such issue on MB and its been long time since I had such issue on other brands.
Anybody has better explanation and possible solutions?
I read the Restore is making "miracle in the pills" that suppose to help with such issues, but never tried it in my life.
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Joined: May 2017
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From: Montreal/Cape Coral FL
2012 X6 35i Sport, 2013 ML 350 BT, 2019 4Runner TRD Pro, 2020 CRV-AWD
Have you done a compression test? Truck must be smoking blue I'd think. Though this is a diesel and I dunno if the DPF would mask the blue smoke.
Thread Starter
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From: V E G A S
1922 Ford Model T / no OBD
No smoke. At least not that I could notice it, but will pay more attention next time.
The smooth test is simulated compression test, so even I don't have psi numbers, I know cylinder #1 has to be lower.
I run the test 6 times and it is pretty consistent.
The smooth test is simulated compression test, so even I don't have psi numbers, I know cylinder #1 has to be lower.
I run the test 6 times and it is pretty consistent.
Last edited by kajtek1; Jul 21, 2018 at 01:26 PM.
MBWorld Fanatic!
Joined: May 2017
Posts: 1,234
Likes: 155
From: Montreal/Cape Coral FL
2012 X6 35i Sport, 2013 ML 350 BT, 2019 4Runner TRD Pro, 2020 CRV-AWD
You may be lucky and it's nothing more than sticky rings. You have nothing to lose bud, throw magic juice into it and cross your fingers.
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
Examine turbo compressor enters and exit, a leak there will push oil through intake where it is almost completely burned with diesel resulting in little to no visible smoke...if intercooler is filled with oil in lower level you can bet it’s either bad oil separator for crankcase breather or bad compressor seal on Garrett GTV turbocharger
Thread Starter
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From: V E G A S
1922 Ford Model T / no OBD
Intercooler always drips oil on those engines as engine breather enters right before turbo, but thank for some additional idea.
Forgot to add that I open oil fill cap and there is not excessive blowby. I am still observing mpg, which seem to be much lower than on original engine, but than I drive in the city, so that changes it a lot.
Forgot to add that I open oil fill cap and there is not excessive blowby. I am still observing mpg, which seem to be much lower than on original engine, but than I drive in the city, so that changes it a lot.
Senior Member
Joined: Jan 2011
Posts: 422
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From: McDade, Texas
W211 e320 CDI
City to highway mpg VASTLY different of course. Looking into turbo entry may answer man questions, you said it feels very strong under throttle, this may well be result of extra oilxfuel getting burned and making power along with diesel under boost. Seen it before, you can always re-route CCV and plug hole, clean up turbo entry with carb or brake cleaner, drive a week and re examine, the answer should be clear then.
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Junior Member
Joined: Nov 2012
Posts: 27
Likes: 3
From: Daytona Bch, FL
2008 GL320 cdi
Seems I just went through this with my r350 bt, it was using a quart every 1000miles and my mileage was for less than my 08 r320cdi, I replace ccv me cause it was not expensive and relatively easy to get to and diy replace. Didn't change a thing. I also had no smoking at all, just losing oil, no leaks, obviously burning through motor. Eventually, I replaced injectors and my starting is great. The DPF was clogged, I think from the excessive oil use and was being caught by the DPF. All this has been in last 2-3 weeks, replacement injectors and cleaned DPF (as of today actually), so I can't report if the injectors and DPF will alter my oil use and bring mpg back to where it should be. If you have good injectors from the old motor, and if you have an Indy with a star or equivalent computer to program the injector codes to ecu then I would say, it could be a possibility. My injectors problem didn't reflect any DTC code whatsoever. And the star or equivalent device showed all compressions within acceptable range. The only symptoms where hard starting, significant oil loss( no leak), and very poor mpg.
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Thread Starter
MBWorld Fanatic!
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From: V E G A S
1922 Ford Model T / no OBD
I have to adjust my starting count as I found another issue.
The engine was taking 1 l of oil for 500 miles when I had small leak. After I fixed the leak, I add oil and soon after I got the cluster message about adding oil, so I was like "Not that S**t again" but after making this topic, I recheck the oil with dipstick and it was at 80% of the scale.
Meaning there is not excessive oil consumption as I assumed, but oversensitive sensor.
My engine starts right away, and I don't have reason to believe there is issue with injectors. They have different serial numbers, what indicate the replacement in car 180k miles life.
We don't drive the car every day, so it takes 3-4 weeks before we use tank of fuel, so it will take time to measure oil consumption more precisely, but the message did not come back, so I keep my fingers crossed.
I can force DPF regeneration with my ICarsoft so will try how much that will help, but replacement injectors are coming with hefty price tag.
Fellow member found a way to rebuild injector on 320cdi engines, but I found no parts for Blutec injectors to rebuild.
I never used any of "miracles in the bottle" stuff, but now might be good time to test one.
Any recommendations for diesel injectors cleaner?
The engine was taking 1 l of oil for 500 miles when I had small leak. After I fixed the leak, I add oil and soon after I got the cluster message about adding oil, so I was like "Not that S**t again" but after making this topic, I recheck the oil with dipstick and it was at 80% of the scale.
Meaning there is not excessive oil consumption as I assumed, but oversensitive sensor.
My engine starts right away, and I don't have reason to believe there is issue with injectors. They have different serial numbers, what indicate the replacement in car 180k miles life.
We don't drive the car every day, so it takes 3-4 weeks before we use tank of fuel, so it will take time to measure oil consumption more precisely, but the message did not come back, so I keep my fingers crossed.
I can force DPF regeneration with my ICarsoft so will try how much that will help, but replacement injectors are coming with hefty price tag.
Fellow member found a way to rebuild injector on 320cdi engines, but I found no parts for Blutec injectors to rebuild.
I never used any of "miracles in the bottle" stuff, but now might be good time to test one.
Any recommendations for diesel injectors cleaner?
Last edited by kajtek1; Jul 28, 2018 at 10:32 AM.
MBWorld Fanatic!
Joined: May 2017
Posts: 1,234
Likes: 155
From: Montreal/Cape Coral FL
2012 X6 35i Sport, 2013 ML 350 BT, 2019 4Runner TRD Pro, 2020 CRV-AWD
There's a thread here where a member rebuilt his injectors and was adamant that he'd done it correctly, yet he ended up replacing them and his hard-starting etc went away immediately.
I wouldn't take the chance but then again, you seem to like to dig into your stuff way more than I do.
I wouldn't take the chance but then again, you seem to like to dig into your stuff way more than I do.
Junior Member
Joined: Nov 2012
Posts: 27
Likes: 3
From: Daytona Bch, FL
2008 GL320 cdi
That sounds like me, I attempted the rebuild of the injectors since I didn’t have anything to loose. I absolutely do not recommend it. I don’t think the om642 injectors can be rebuilt except by Bosch manufacturer after the attempt. I was lucky to find six that had a guarantee of money back, for $100 each. And after trying the various bottles of injector cleaners, I don’t think they do a thing better than just having clean fuel.
I only threw out the idea because of some common symptoms, like significant oil consumption, and poor mpg that neither presented with codes or diagnostic data. But seems on e symptom was explained with the sensitive sensor. As far as the injectors, I thought you still had the original engine with its six injectors, that I assumed were functioning, and the replacement motor had its six. I would in no way suggest buying new injectors unles it was an absolute last resort, not only are they expensive but each has to be programmed into the ecu via STAR or equivalent computer and unless you have a fantastic independent shop like mine that let me change the injectors on the lot and they just did the programming. Injector swapping is LAST resort.
I only threw out the idea because of some common symptoms, like significant oil consumption, and poor mpg that neither presented with codes or diagnostic data. But seems on e symptom was explained with the sensitive sensor. As far as the injectors, I thought you still had the original engine with its six injectors, that I assumed were functioning, and the replacement motor had its six. I would in no way suggest buying new injectors unles it was an absolute last resort, not only are they expensive but each has to be programmed into the ecu via STAR or equivalent computer and unless you have a fantastic independent shop like mine that let me change the injectors on the lot and they just did the programming. Injector swapping is LAST resort.
