Guru required PLEASE.. 2010 C250 CGI. 1.8 TURBO petrol in oil problem.
Thread Starter
Newbie
Joined: Aug 2017
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S204... c250 petrol turbo.
Guru required PLEASE.. 2010 C250 CGI. 1.8 TURBO petrol in oil problem.
Hi I have the above car 1.8 turbo c250 cgi,
I recently changed the oil as it appeared I'd slight over filled on my last change.. Not a mistake I make. And changed oil etc 2 weeks ago and put 5.5 litres in leaving it bang on between min and max on the dipstick.
I checked it again yesterday and the level is just over max again and it appears petrol is getting in the oil.
I do have the problem of lots of small journeys and understand that the most likely cause it an injector stuck open and there isn't many options for fuel to get there.. But this is not a good scenario at all.
The car does run fine, doesn't misfire etc but I'm now not going to use it till I can sort this out.
Has anyone had this problem and what was their result as the more info the better.
Thanks
I recently changed the oil as it appeared I'd slight over filled on my last change.. Not a mistake I make. And changed oil etc 2 weeks ago and put 5.5 litres in leaving it bang on between min and max on the dipstick.
I checked it again yesterday and the level is just over max again and it appears petrol is getting in the oil.
I do have the problem of lots of small journeys and understand that the most likely cause it an injector stuck open and there isn't many options for fuel to get there.. But this is not a good scenario at all.
The car does run fine, doesn't misfire etc but I'm now not going to use it till I can sort this out.
Has anyone had this problem and what was their result as the more info the better.
Thanks
Newbie
Joined: Oct 2010
Posts: 14
Likes: 2
Mercedes-Benz E250 CGI
Searching on forum found your post. I'm no guru but I have same engine, another suggestion is to change the Ventilation valve for crankcase gases that lets the petrol evaporate from oil. Code for Part: A2710180729 This valve should be changed every 30,000 Miles from what I read on forums. Valve gets stuck in small journeys situation .... from what I read.
Thread Starter
Newbie
Joined: Aug 2017
Posts: 9
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S204... c250 petrol turbo.
Searching on forum found your post. I'm no guru but I have same engine, another suggestion is to change the Ventilation valve for crankcase gases that lets the petrol evaporate from oil. Code for Part: A2710180729 This valve should be changed every 30,000 Miles from what I read on forums. Valve gets stuck in small journeys situation .... from what I read.
Newbie
Joined: Oct 2018
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C250
Thanks for this reply, I actually have replaced this now.. I came across the valve while looking at the injectors and high pressure fuel pump.. Sure enough it was stuck and I couldn't even get an airline to open the valve.. The new one blew open with a small blow from my mouth so the other was definitely faulty.. I am now back in testing stage to see if the problem is still there or not.
Newbie
Joined: Dec 2024
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Anyone found the fix ?
Thanks for this reply, I actually have replaced this now.. I came across the valve while looking at the injectors and high pressure fuel pump.. Sure enough it was stuck and I couldn't even get an airline to open the valve.. The new one blew open with a small blow from my mouth so the other was definitely faulty.. I am now back in testing stage to see if the problem is still there or not.
i’m getting a little frustrated
has anyone found the fix to this ?
kind regards
Last edited by ricardo155; Dec 29, 2024 at 05:27 PM. Reason: Missing info
Junior Member
Joined: Feb 2025
Posts: 18
Likes: 4
From: NC
2014 W204 C250
If I had to guess, I would say a stuck injector, since fuel can only get into the cylinder via an injector and the only way for the fuel to get into the oil is through the piston seals, they do leak, especially liquid fuel.
The other possibility is the high pressure fuel pump somehow failing and letting fuel into the oil.
I would take out the spark plugs and see which cylinder has unburned fuel in it to possibly get an idea if it's one of the cylinders.
A stuck injector can be checked with compressed air, after removing it from the engine, as it will leak and you can see that when submerging it in liquid. I would use injector cleaner just to be safe, but degreaser or even water works just fine for a quick test under pressure, of course this is not the correct way to test, but a backyard mechanic way.
As far as the valve that was replaced, I had the same issue recently stuck closed, and I found a bunch of sludge in my oil pan, but no petrol/gasoline.
The other possibility is the high pressure fuel pump somehow failing and letting fuel into the oil.
I would take out the spark plugs and see which cylinder has unburned fuel in it to possibly get an idea if it's one of the cylinders.
A stuck injector can be checked with compressed air, after removing it from the engine, as it will leak and you can see that when submerging it in liquid. I would use injector cleaner just to be safe, but degreaser or even water works just fine for a quick test under pressure, of course this is not the correct way to test, but a backyard mechanic way.
As far as the valve that was replaced, I had the same issue recently stuck closed, and I found a bunch of sludge in my oil pan, but no petrol/gasoline.
Last edited by petarld; May 22, 2025 at 05:15 PM.
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2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Mitigation includes higher viscosity oil, longer drives at full operating temperature, and more frequent oil changes.
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Joined: Sep 2013
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2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320
Hi I have the above car 1.8 turbo c250 cgi,
I recently changed the oil as it appeared I'd slight over filled on my last change.. Not a mistake I make. And changed oil etc 2 weeks ago and put 5.5 litres in leaving it bang on between min and max on the dipstick.
I checked it again yesterday and the level is just over max again and it appears petrol is getting in the oil.
I do have the problem of lots of small journeys and understand that the most likely cause it an injector stuck open and there isn't many options for fuel to get there.. But this is not a good scenario at all.
The car does run fine, doesn't misfire etc but I'm now not going to use it till I can sort this out.
Has anyone had this problem and what was their result as the more info the better.[size=33px]
I recently changed the oil as it appeared I'd slight over filled on my last change.. Not a mistake I make. And changed oil etc 2 weeks ago and put 5.5 litres in leaving it bang on between min and max on the dipstick.
I checked it again yesterday and the level is just over max again and it appears petrol is getting in the oil.
I do have the problem of lots of small journeys and understand that the most likely cause it an injector stuck open and there isn't many options for fuel to get there.. But this is not a good scenario at all.
The car does run fine, doesn't misfire etc but I'm now not going to use it till I can sort this out.
Has anyone had this problem and what was their result as the more info the better.[size=33px]
It’s not uncommon on the M271 EVO engine.
https://mbworld.org/forums/c-class-w...ase-issue.html
Junior Member
Joined: Feb 2025
Posts: 18
Likes: 4
From: NC
2014 W204 C250
It’s not uncommon on the M271 EVO engine.
https://mbworld.org/forums/c-class-w...ase-issue.html
https://mbworld.org/forums/c-class-w...ase-issue.html
Junior Member
Joined: Feb 2025
Posts: 18
Likes: 4
From: NC
2014 W204 C250
The Honda oil dilution problem primarily affects vehicles with the 1.5-liter turbo engine, where fuel mixes with engine oil, leading to potential engine damage. This issue has been linked to the engine's design and has resulted in class action lawsuits against Honda, prompting the company to extend warranties and offer software updates to mitigate the problem.
If that was the case we would be hearing about more issues like this instead of stuck injectors, I am also not aware of any class action lawsuits for the M271.860 Evo engine design. The engine does have a design flaw, the lack of oil lubrication on the timing chain leading to premature wear, but I digress.
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2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320
Junior Member
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From: NC
2014 W204 C250
The only thing not addressed so far by OP Is the injectors. My PCV valve was plugged and I did not find any fuel in my oil, only sludge in the oil pan, yes I took it off to clean it. Half a liter of fuel in the oil cannot be caused by Valve Cover or PCV System being clogged as there is still some venting through the block to the head and out the valve cover. The valve cover only contains an oil separator, no valves or anything restricting flow in any direction as I figured out based on testing by blow air back into the valve cover.
Last edited by petarld; May 24, 2025 at 04:16 PM.
