R320 Bluetec oil consumption
Thread Starter
Junior Member
Joined: Dec 2022
Posts: 56
Likes: 13
2012 MB R350 Bluetec
R320 Bluetec oil consumption
Hi all, I have a 2009 R320 Bluetec.
It has 220 km on it.
It is suffering from excessive oil consumption at 1.5 to 2 L per 1000 km.
This issue has been happening for the last 7000 km. Low oil confirmed on dipstick as well.
I had the bluetec recall completed 4000 km. I was hoping that once the PCV valve was replaced, the issue might relieve itself.
Unfortunately, despite PCV valve and the rest of bluetec recall (which includes lots of new parts), the issue persists.
There are no external leaks. I use 229.52 oil (mobil 1 ESP).
I took the car to the mercedes dealership locally today.
They could find no external leaks.
They suggested if I want to pursue this further, it would require an oil consumption test, which would cost $600 dollars, and it would only tell me what I already know!!
They do not want to delve further into diagnostics without doing an oil consumption test.
I did ask whether they would be able to replace the turbo under the bluetec warranty, but they said that there is no sign that either the turbo or the piston rings are the issue, as they say that the car would emit lots of white/blue smoke if either of these issues were the problem. The car does not emit smoke at all, it drives perfectly, with full power, and normal fuel economy.
I love the van. I do not know whether to go down this rabbit hole, as it will be very heavy on the wallet. The car is in mint condition otherwise.
What do you guys recommend?
Is it better to sell the car?
Should I go down this diagnostic rabbit hole?
What are other things that could cause oil consumption?
It has 220 km on it.
It is suffering from excessive oil consumption at 1.5 to 2 L per 1000 km.
This issue has been happening for the last 7000 km. Low oil confirmed on dipstick as well.
I had the bluetec recall completed 4000 km. I was hoping that once the PCV valve was replaced, the issue might relieve itself.
Unfortunately, despite PCV valve and the rest of bluetec recall (which includes lots of new parts), the issue persists.
There are no external leaks. I use 229.52 oil (mobil 1 ESP).
I took the car to the mercedes dealership locally today.
They could find no external leaks.
They suggested if I want to pursue this further, it would require an oil consumption test, which would cost $600 dollars, and it would only tell me what I already know!!
They do not want to delve further into diagnostics without doing an oil consumption test.
I did ask whether they would be able to replace the turbo under the bluetec warranty, but they said that there is no sign that either the turbo or the piston rings are the issue, as they say that the car would emit lots of white/blue smoke if either of these issues were the problem. The car does not emit smoke at all, it drives perfectly, with full power, and normal fuel economy.
I love the van. I do not know whether to go down this rabbit hole, as it will be very heavy on the wallet. The car is in mint condition otherwise.
What do you guys recommend?
Is it better to sell the car?
Should I go down this diagnostic rabbit hole?
What are other things that could cause oil consumption?
MBWorld Fanatic!
Joined: Jan 2016
Posts: 2,748
Likes: 880
From: In the Shadow of the Tetons
2013 ML350 Bluetec
Have you pulled the underbelly to look closely? It's either coming out the engine exterior or it's going out the tailpipe... that much oil consumption should be easily found.
Junior Member
Joined: Aug 2020
Posts: 52
Likes: 13
2009 GL 320
I'm in the same boat. 09 GL320 with 192k miles. For last 10,000 miles I have used about 12 quarts. Had AEM + oil cooler done in Feb 2022 then noticed oil consumption. Replaced vacuum pump gaskets and new oil filter housing as those were leaking but no joy. Motor runs great, normal 20-24mpg, no smoke. I wonder if exhaust gets hot enough to burn it clean.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
For starters, start making paper record about oil additions.
We had sedan owner having high oil consumption and having extended warranty, he took it to dealer. Don't remember the number, but MB allows for quite hefty oil consumption before raising red flag.
That said, after 2 years of searching, one of the repairs found oil leak in hard to see place on member's car.
Having warranty I would keep on driving. I know warranty doesn't cover everything, but it is making some confidence.
We had sedan owner having high oil consumption and having extended warranty, he took it to dealer. Don't remember the number, but MB allows for quite hefty oil consumption before raising red flag.
That said, after 2 years of searching, one of the repairs found oil leak in hard to see place on member's car.
Having warranty I would keep on driving. I know warranty doesn't cover everything, but it is making some confidence.
MBWorld Fanatic!
Joined: May 2017
Posts: 2,290
Likes: 434
C320
I did ask whether they would be able to replace the turbo under the bluetec warranty, but they said that there is no sign that either the turbo or the piston rings are the issue, as they say that the car would emit lots of white/blue smoke if either of these issues were the problem. The car does not emit smoke at all, it drives perfectly, with full power, and normal fuel economy.
I love the van. I do not know whether to go down this rabbit hole, as it will be very heavy on the wallet. The car is in mint condition otherwise.
What do you guys recommend?
Is it better to sell the car?
Should I go down this diagnostic rabbit hole?
What are other things that could cause oil consumption?
Your piston rings are shot. I've seen this many times on the om642s. There's nothing you can do about it except rebuilt or replace the engine. The culprit is a combination of MB specifying the wrong oil with far too long oil change intervals, excessive EGR and frequent DPF regenerations. Together they conspire to damage the oil control rings on this engine.
Last edited by tjts1; Feb 4, 2023 at 02:26 AM.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
220k k km is low mileage for diesel, but as long topic about seized engines show, the OM642 can be very sensitive to oil quality.
That said you can do simulated compression test with better scanner, who will give you an idea about pistons condition.
That said you can do simulated compression test with better scanner, who will give you an idea about pistons condition.
MBWorld Fanatic!
Joined: Jan 2013
Posts: 3,745
Likes: 811
From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
Remove the DPF from under the car and have a look in the rear view mirror as you drive it around the block. You'll find your smoke. The DPF is designed to catch the diesel soot and periodically burn it off. It also coincidentally catches the oil smoke your engine is burning.
Your piston rings are shot. I've seen this many times on the om642s. There's nothing you can do about it except rebuilt or replace the engine. The culprit is a combination of MB specifying the wrong oil with far too long oil change intervals, excessive EGR and frequent DPF regenerations. Together they conspire to damage the oil control rings on this engine.
Your piston rings are shot. I've seen this many times on the om642s. There's nothing you can do about it except rebuilt or replace the engine. The culprit is a combination of MB specifying the wrong oil with far too long oil change intervals, excessive EGR and frequent DPF regenerations. Together they conspire to damage the oil control rings on this engine.
With regular oil changes, 220K kms is relatively little on an OM642 engine. The fact that the OP is using kilometers could mean that he's not in the USA, so it could be something relatively inexpensive to fix - but someone needs to figure out where the oil is going first.
Trending Topics
Thread Starter
Junior Member
Joined: Dec 2022
Posts: 56
Likes: 13
2012 MB R350 Bluetec
It's tough to know how regular the oil changes were on this van, as the majority of ownership was prior to me.
I have had it for 4 months, and 7500 km of ownership, and yes I use kilometre nomenclature as I am in Canada.
If we humour the idea that Sludge and carbon deposits have lodged in the oil control piston rings, is there anything other than an engine teardown that could be tried? Any solvents that are worth trying that could break down Sludge and maybe 'free up' the piston ring?
I have had it for 4 months, and 7500 km of ownership, and yes I use kilometre nomenclature as I am in Canada.
If we humour the idea that Sludge and carbon deposits have lodged in the oil control piston rings, is there anything other than an engine teardown that could be tried? Any solvents that are worth trying that could break down Sludge and maybe 'free up' the piston ring?
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Junior Member
Joined: Dec 2022
Posts: 56
Likes: 13
2012 MB R350 Bluetec
The only thing I just noticed a minute ago is if I remove the oil cap while the engine is running, it shoots off all this smoke and little flecks of oil. Is that called blow by? Is that normal?
MBWorld Fanatic!
Joined: Jan 2013
Posts: 3,745
Likes: 811
From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
It's tough to know how regular the oil changes were on this van, as the majority of ownership was prior to me.
I have had it for 4 months, and 7500 km of ownership, and yes I use kilometre nomenclature as I am in Canada.
If we humour the idea that Sludge and carbon deposits have lodged in the oil control piston rings, is there anything other than an engine teardown that could be tried? Any solvents that are worth trying that could break down Sludge and maybe 'free up' the piston ring?
I have had it for 4 months, and 7500 km of ownership, and yes I use kilometre nomenclature as I am in Canada.
If we humour the idea that Sludge and carbon deposits have lodged in the oil control piston rings, is there anything other than an engine teardown that could be tried? Any solvents that are worth trying that could break down Sludge and maybe 'free up' the piston ring?
There are many places where the oil could be going (either leaking or being ingested into the engine one way or another), so stuck piston rings would not be my first guess. If you've just bought it however and you don't have the full service history, all bets are off... a lot of folks can't afford to properly service them (or they use them as grocery getters, which is not the best use of any diesel and in particular an OM642). The engines themselves are workhorses and last forever when properly used and maintained, but nothing is impervious to failure if neglected.
I don't know of any "flush treatment" oil additives that actually work. Modern oil chemistry has improved so much in the last decade or so that the oil itself has all the detergents and additives the engine needs (assuming that you're using the correct oil of course), and adding anything to it is bound to cause more damage than good.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
I start with a napkin over oil fill hole and all my engines will not blow it at idle.
When napkin gets blown away, try a piece of cardboard.
When the cardboard gets blown away, start checking why.
Did I miss the info when was the last oil change? Do you use 229.52 category oils?
Last edited by kajtek1; Feb 5, 2023 at 11:49 AM.
MBWorld Fanatic!
Joined: May 2017
Posts: 2,290
Likes: 434
C320
I've done a number of statistical failure analyses for Mercedes, and the number of OM642 engines with failed piston rings UNLESS there was a problem as a result of inadequate oil changes are negligible (as in less three per 10,000 engines or something along those lines). Inadequate oil changes (interval and/or oil type) are indeed a big issue in the USA states where there is high biodiesel content in the fuel, and likely what you're referring to. If the oil control rings get stuck in the grooves, it's because the oil has turned into sludge and the engine is indeed shot.
With regular oil changes, 220K kms is relatively little on an OM642 engine. The fact that the OP is using kilometers could mean that he's not in the USA, so it could be something relatively inexpensive to fix - but someone needs to figure out where the oil is going first.
With regular oil changes, 220K kms is relatively little on an OM642 engine. The fact that the OP is using kilometers could mean that he's not in the USA, so it could be something relatively inexpensive to fix - but someone needs to figure out where the oil is going first.
220k miles, 10k mile OCIs with 229.52 oil. The oil control ring was firmly stuck in the groove. You can't blame this on biodiesel.
Last edited by tjts1; Feb 6, 2023 at 02:22 AM.
MBWorld Fanatic!
Joined: Jan 2013
Posts: 3,745
Likes: 811
From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
Well what exactly is "inadequate oil changes? 10,000 miles or the current 20,000 miles Mercedes is pushing? I agree that inadequate oil changes is a contributing factor but the blame is on Mercedes for telling customers they should go that long. And excessive EGR is also a factor when the intake ports look like this.
220k miles, 10k mile OCIs with 229.52 oil. The oil control ring was firmly stuck in the groove. You can't blame this on biodiesel.
Congratulations! It sounds like you one of the negligible number of om642s with failed piston rings. I happen to own 2 of those negligible engines. I guess the two of use together are the lucky 3/10,000. All you other 9,997 om642 owners are safe.
220k miles, 10k mile OCIs with 229.52 oil. The oil control ring was firmly stuck in the groove. You can't blame this on biodiesel.
Congratulations! It sounds like you one of the negligible number of om642s with failed piston rings. I happen to own 2 of those negligible engines. I guess the two of use together are the lucky 3/10,000. All you other 9,997 om642 owners are safe.
As for your 220K mile engine with seized piston rings, even without knowing how the car was driven, at 220K miles - or 354,000 kilometers - that engine doesn't owe you anything. Period. That is more than the life expectancy of any consumer engine, and I'd call that distance respectable by any standard. If the motor was in a commercial Sprinter and it had been properly serviced and/or overhauled, it could probably could have gone a little longer, but you getting your knickers in a twist over a motor with 220K miles is like blaming someone's death on drinking polluted water that "caused" their death at the age of 102. You might want to consider adjusting your expectations somewhat. If you don't know the complete vehicle history, how it was maintained or if it was driven on short trips and you got 220K miles out of it with 10K mile OCIs, you should be thanking Mercedes for building you something as reliable. Try doing that with any other car and let me know how you make out.
MBWorld Fanatic!
Joined: May 2017
Posts: 2,290
Likes: 434
C320
What an adequate OCI is depends entirely on how you drive your vehicle, and the only proper way to determine that is by doing a UOA. If you're driving long distances and your oil stays hot for 5+ hours at a time, a 10K OCI may be perfectly fine. If you're idling in traffic and driving short distances, even a 5K OCI is inadequate. A 20K OCI is pretty much guaranteed to kill your motor, and I would furthermore really like to see where Mercedes is pushing for a 20K mile OCI.
As for your 220K mile engine with seized piston rings, even without knowing how the car was driven, at 220K miles - or 354,000 kilometers - that engine doesn't owe you anything. Period. That is more than the life expectancy of any consumer engine, and I'd call that distance respectable by any standard. If the motor was in a commercial Sprinter and it had been properly serviced and/or overhauled, it could probably could have gone a little longer, but you getting your knickers in a twist over a motor with 220K miles is like blaming someone's death on drinking polluted water that "caused" their death at the age of 102. You might want to consider adjusting your expectations somewhat. If you don't know the complete vehicle history, how it was maintained or if it was driven on short trips and you got 220K miles out of it with 10K mile OCIs, you should be thanking Mercedes for building you something as reliable. Try doing that with any other car and let me know how you make out.
As for your 220K mile engine with seized piston rings, even without knowing how the car was driven, at 220K miles - or 354,000 kilometers - that engine doesn't owe you anything. Period. That is more than the life expectancy of any consumer engine, and I'd call that distance respectable by any standard. If the motor was in a commercial Sprinter and it had been properly serviced and/or overhauled, it could probably could have gone a little longer, but you getting your knickers in a twist over a motor with 220K miles is like blaming someone's death on drinking polluted water that "caused" their death at the age of 102. You might want to consider adjusting your expectations somewhat. If you don't know the complete vehicle history, how it was maintained or if it was driven on short trips and you got 220K miles out of it with 10K mile OCIs, you should be thanking Mercedes for building you something as reliable. Try doing that with any other car and let me know how you make out.
Mercedes used to build reliable engines. That ended before the om642 hit the market. Sadly the OPs story is very common on the 642 forums. Your 3/10,000 claim is laughable and trying to shift blame on the owners is downright slimy. Mercedes designed and built a turd in the 642. I expect far more than 220k miles from a Mercedes engine.
Last edited by tjts1; Feb 6, 2023 at 02:35 AM.
MBWorld Fanatic!
Joined: Jan 2013
Posts: 3,745
Likes: 811
From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
Because of what was allowed to come out of the tailpipe when they were designed. Trying to control NOx emissions was unheard of. How much EGR is there on any of those three (including on the M112 which is a different animal altogether should not be grouped with the diesels)?
MBWorld Fanatic!
Joined: Jan 2013
Posts: 3,745
Likes: 811
From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
Mercedes used to build reliable engines. That ended before the om642 hit the market. Sadly the OPs story is very common on the 642 forums. Your 3/10,000 claim is laughable and trying to shift blame on the owners is downright slimy. Mercedes designed and built a turd in the 642. I expect far more than 220k miles from a Mercedes engine.
Thread Starter
Junior Member
Joined: Dec 2022
Posts: 56
Likes: 13
2012 MB R350 Bluetec
I listed the R320 for sale because this oil consumption issue is really bothering me.
A person reached out to me on kijiji, and he mentioned his r-class 2009 R320 bluetec did the same consumption of oil in the past. He mentions his oil consumption started at 195000 km. He kept refilling the oil initially as the issue persisted. He was told he needs a new engine. A mechanic recommended he use thicker oil. He started using Rotella T6 15W-40 oil. He says that his oil consumption stopped. He tells me he has 395,000 km on the vehicle, which is unreal. Is this story too good to be true? Has anyone else used much thicker viscosity oil and had good results? From a mechanistic point of view, it could make sense (if oil is more viscous, less is getting past piston rings or valve stem seals).
Has anyone else run more viscous oil in their OM642 engines, and had success?
A person reached out to me on kijiji, and he mentioned his r-class 2009 R320 bluetec did the same consumption of oil in the past. He mentions his oil consumption started at 195000 km. He kept refilling the oil initially as the issue persisted. He was told he needs a new engine. A mechanic recommended he use thicker oil. He started using Rotella T6 15W-40 oil. He says that his oil consumption stopped. He tells me he has 395,000 km on the vehicle, which is unreal. Is this story too good to be true? Has anyone else used much thicker viscosity oil and had good results? From a mechanistic point of view, it could make sense (if oil is more viscous, less is getting past piston rings or valve stem seals).
Has anyone else run more viscous oil in their OM642 engines, and had success?
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
Is your 2009 having SCR system, with DEF injection?
If yes, those engines seems to be very sensitive to lower class oils, but older models seem to work with older generation oils just fine.
Since oil topics are always religion-driven on internet forums, I would be careful with taking seriously presented personal opinions.
Maybe somebody using Rotella will come with lab test results, but other than that, you might want to fill that oil and test it after 1000 km.
If yes, those engines seems to be very sensitive to lower class oils, but older models seem to work with older generation oils just fine.
Since oil topics are always religion-driven on internet forums, I would be careful with taking seriously presented personal opinions.
Maybe somebody using Rotella will come with lab test results, but other than that, you might want to fill that oil and test it after 1000 km.
Thread Starter
Junior Member
Joined: Dec 2022
Posts: 56
Likes: 13
2012 MB R350 Bluetec
I would not even know where to go for an oil analysis. I also have no idea how to interpret oil analysis, maybe it generates an automatic interpretation, which would be nice.
But if not, never order a diagnostic test, where you don't know what to do with the results.
But if not, never order a diagnostic test, where you don't know what to do with the results.
Junior Member
Joined: Feb 2015
Posts: 43
Likes: 8
2013 GLK 250 BT
MBWorld Fanatic!
Joined: Jun 2021
Posts: 1,919
Likes: 522
From: New Hampsha
'17 GLS450, '14 GLK250, Grandpa's Roadster
Blackstone will provide an interpretation. One thing, though, is that oil analysis is much more useful for analyzing trends. A one time sample lacks context. Still, they usually provide comments based on expected results form other similar vehicles and engines.
I have had encouraging results using a heavy dose of Liqui Moly Pro Line Engine Flush. I recall I used two 500ml bottles with about 7 quarts of oil. Oil consumption declined noticeably over the next 5000 miles or so.
You add it right before an oil change, so the car doesn't get driven with the stuff in the oil.
For me, it was worth the expense and effort. The engine still used oil, but it was at a much more reasonable rate. YMMV.
I have had encouraging results using a heavy dose of Liqui Moly Pro Line Engine Flush. I recall I used two 500ml bottles with about 7 quarts of oil. Oil consumption declined noticeably over the next 5000 miles or so.
You add it right before an oil change, so the car doesn't get driven with the stuff in the oil.
For me, it was worth the expense and effort. The engine still used oil, but it was at a much more reasonable rate. YMMV.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
As mentioned, blackstone will interpret the results. You can find copies of reports in archives, but the site gives the sample as well.
I used them a lot few years ago, when industry had big categories wars and I could not find independent test available and old "Customer Report" publication got corrupted.
Having Ford truck, who I used a lot, I was using different brands of oils and sending for test. Surprise, the Ford-recommended oil was the worse from the series, when dino Rotella won hands down.
Lately you can find youtube channel "Project Farm" where the guy takes his time to do some tests. When he can't do chemical test, he will show you how different oils act mechanically.
He does a lot of test, comparing jack stands, tools and more.
I used them a lot few years ago, when industry had big categories wars and I could not find independent test available and old "Customer Report" publication got corrupted.
Having Ford truck, who I used a lot, I was using different brands of oils and sending for test. Surprise, the Ford-recommended oil was the worse from the series, when dino Rotella won hands down.
Lately you can find youtube channel "Project Farm" where the guy takes his time to do some tests. When he can't do chemical test, he will show you how different oils act mechanically.
He does a lot of test, comparing jack stands, tools and more.
MBWorld Fanatic!
Joined: Jan 2013
Posts: 3,745
Likes: 811
From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
Where in Canada are you located?
MBWorld Fanatic!
Joined: Jan 2013
Posts: 3,745
Likes: 811
From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
For the Sprinters we use either Toromont (https://www.toromontcat.com/service/...alysis-program) or WearCheck (https://wearcheck.ca/). For some of the race engines we've also used AGAT Laboratories. All are local (GTA) and can do a used oil analysis. Call them and find out where you can drop off a sample.
