mtrevelino

Hello All,
I have a 2006 cdi, 170K miles, build date 02/06. Whenever I come to a stop for more than 20 seconds, I start smelling fumes come in through the air vents. When I park my car in the garage, it will smell a lot. I took off the sound dampening covers to look for any leaks, I did not see any.
When I remove the oil fill cap while the motor is running, I can see some vapors come out of the opening. This also resembles the smell more than the typical diesel exhaust smell. My thinking is that it may be a partially clogged EGR valve/system. From the two MB forums I belong to, I thought 95-percent of the EGR issues had to do with model year 2005 cdi's. I may be the 5-percent of the 2006 cdi's that is experiencing this.
My question is, what are the symptoms of a clogged EGR? At this time no codes are being thrown, or at least no check engine light. This is something I will let my indie check when I get the time, but I just wanted to see if anyone has experienced this before.
I am also going to post this in the other forum (we are not suppose to mention) because there may be a few others that do not go into both forums.
Thank you!
Mike T.

Micah / AF1 Rac

drewkeen

Take off the silencing cover, leave the hood open and start the car. Do you hear a "chuffing" sound coming from the engine?

You could also check the torque on the turbo and exhaust manifold bolts. I had a few bolts on the manifold loosen, it also caused a whistling sound at lower engine speeds because of the slight leak when the vanes were closed.

mtrevelino

It is not raw diesel or a burned diesel smell. If I remove the oil filler cap and take a wiff, this is the smell that is coming into the cab.
Mike T.

mtrevelino

I had to look that up. No chuffing sound. No whistling sound. Someone on the other forum mentioned it could be the crankcase ventilation system.
Thanks,
Mike T.

DansGL

I had an exhaust leak under the car that did the same thing. Your setup is probably different but my leak was at the clamp joining the DPF to CAT.

mtrevelino

Thanks! It may be an exhaust leak before the cat. If it is a leak, there is no additional noise, just smell. I will post when I find out for sure.
Mike T.

Trevor Simpson

I have the exact same problem right now. I have only owned the car for a month or two and it's only been running for a week. I figured it was because oil got spewed all over everything so it was burning off. We steam cleaned the engine but 1000 miles later I still get the intermittent smell as you described. Only when stopped. I haven't dug too deep into it yet because I am busy trying to fix everything else lol.

lkchris

On my 642 V6 the leak was at a gasket in the EGR plumbing ... mistake by mechanic he got to correct.

mtrevelino

Thanks Kent, I will keep that in mind.
Mike T.

rocky472

I have the same issue with my 2005 e320 CDI. I purchased it in February this year. It currently has 197K miles. My first thought was burning oil but it happens immediately after startup. The exhaust smell is very strong, especially if the car has not been backed out of the garage. I also notice it at long stop lights. I was under the car changing the engine mounts and didn't see any black soot marks on the exhaust joints. Planning on removing the air filter housing to see if there is anything obvious from the top side. I opened my oil filler cap and didn't notice any smoke so I am guessing it's somewhere in the exhaust plumbing. Also checked the injectors, no "Black Death" issues. Any ideas from the group would be appreciated. Love driving this car. The torque and fuel economy is amazing.

mtrevelino

I have not had a chance to get to my indie yet to check this. The smell is not as bad after I replaced the air/oil separator, but it is still there. I need to check to see if there are any codes thrown that does not cause the engine light to light. Is that possible that a code is thrown without the check engine light coming on????
Mike T.

Micah / AF1 Rac

It is most definitely possible! I work on motorcycles for a living, find MANY stored and inactive codes, MANY, almost every Ecu I hook up to honestly. Granted I work on exotic Italian two wheeled stuff but I’m guessing it’s the same across the transportation industry.

rocky472

I checked my car for engine codes. Nothing stored, pending or historical.

mtrevelino

I also checked mine and no codes. I will let everyone know when my indie looks at it.
Mike T.

evan717

I just rectified my issue with exhaust smell inside the cabin: have you checked your injectors for black death? I swore I did not have it until I listened closely with mechanic's stethoscope. Sure enough I had a bad injector seal. This is an incredibly simple job if you do not have issues removing the injectors themselves. One recommendation is to purchase long q-tips. Let me know if you have any further questions but research black death if you are not familiar.

mtrevelino

I do not have a exhaust smell. The smell is oil vapors. I removed the covers and all injectors are dry. I have an appointment with my indie on the 25th of this month. I can say that the smell has decreased by half since I replaced the oil separator. My indie said that would have been his first thought, but will dig deeper when I drop it off.
Mike T.

evan717

I could not pinpoint the exact smell being exhaust or diesel leak or oil vapors either and my injectors were relatively dry upon initial investigation. I did not have severe black death but the failed washer was definitely allowing fuel/air mixture or exhaust into engine bay. Just worth 5 min of further investigation to rule it out 100%. As far as a definitive engine oil smell: has to be related to crankcase vent system. As far as I know the OM648 does not have a pressurized crank and those oil vapors should be venting to intake. There are two seals under oil sep:

mtrevelino

ok, just to bring everyone up to date on this and to close this out. One month and 1,500 miles ago, I replaced the oil separator with a Viaco brand oil separator. The oil smell decreased by at least half immediately. During the following weeks and finally today, I can say the smell is completely gone.
I stopped by my indie and spoke to him a couple of weeks ago while the smell was still there. He said that the first thing he would have checked was the oil separator. I stopped again this morning and told him the smell was completely gone. He said that when I changed the oil separator and without thoroughly cleaning the system, that it could take a week or two for everything to resume to normal. He said that there could have been oil stuck in places it should not have been, and took time to clear.
Anyway, that is my story. Thanks for those that offered suggestions.
Mike T.

rocky472

Update on my CDI. I changed the oil separator in April going with the Vaico aftermarket brand. Initially the odor level decreased. After a few weeks of driving, the odor intensity increased to the point the smell never went away. Previously it was only at initial startup. I also noticed oil drips under the car. Removing the air cleaner housing I found the entire right side of the engine covered with oil. Including the exhaust manifold and turbo. The oil separator had puddles of oil on top of the housing. I confirmed it was not leaking from the oil filler cap. The air filter heat shield (above the catalyst and turbo) had a thick oil residue and was wet with oil. A weep hole in the back of the heat shield was dripping oil directly on the catalyst. I removed the heat shield and degreased everything. The oil separator was replaced with the Mercedes OEM. It was about $30 cheaper than the Vaico. After a week of driving the odor is 100% gone! Looking at the oil separator construction, there are two forward chambers that have welded or glued lids. What I think happened is it leaked from the top of one of these chambers. Another observation is the MB part installed very easily, only took two fingers to push it in. The Vaico was much more difficult to install. Makes me wonder if the distance between the lower mounting features was correct.

mtrevelino

I am glad you have it finally fixed. Mine has been good since I changed it out. I did order a new oil filler cap as there was a little oil poling just below it. Again, everything is dry.
Mike T.