What Does Your Engine Smell Like After Running Hot?

Jan 20, 2011 | 09:42 AM

mrobinso

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2021 Yukon XL Denali, 2017 GLS450 4MATIC, 1993 Chevy Corvette

What Does Your Engine Smell Like After Running Hot?

I couldn't find a decent answer to this anywhere. To all C55 owners, how does your car's engine smell after running it hot for about 10 to 15 minutes (for example, after your commute home from work)?

I have noticed that I have a kind of rubber burning/oil burning smell that is not overpowering, but that I can smell once I step out of the cabin of the car. If I put my nose to the grill of the car, I can smell it clearly. I know that what I am smelling is a smell most commonly associated with burning oil, or heated mechanical plastics or metals. Do you think this smell could be simply a result of the C55 engine bay's propensity to heat up with little outlet for the heat to escape? I wouldn't say I am worried, as I have had no problems driving the car for 9,000 miles, but I am curious as to whether or not mine is an unusual case or not.

Jan 20, 2011 | 11:51 AM

400+ HPC32 AMG

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2002 C32 amg

possibly a valve cover gasket causing a little oil to drip onto the exhaust manifold. A tiny drop here and there will lead to exactly what you describe, although could be something else. I have had a similar issue and it went away..

Jan 20, 2011 | 11:52 AM

AMG Sleeper

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From: Washington, DC

2005 C55 AMG, 2010 VW GTI (Stage 1)

I had the same issue two weeks ago, to me it smelled like a burnt rubber belt or something - first thing I did was get an oil change, which made the car ride smoother but the smell would come back whenever I had the air/heat on. It ended up being the engine valve cover gasket (the rubber that keeps the inside insulated), it turns out the one I had wasn't sitting flush in the valve cover, so the oil would leak out onto the engine, burn off, and then that air would go in from the air filter inside the car... hence that burning smell

my suggestion - get a tech to look at your valve cover gaskets (it's literally a round piece of rubber, but it needs to fit on flush)

good luck!

Jan 20, 2011 | 12:20 PM

mrobinso

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2021 Yukon XL Denali, 2017 GLS450 4MATIC, 1993 Chevy Corvette

Thanks for both responses. AMG Sleeper, it would be very helpful if you could point me where to look for the valve cover gasket in the engine bay (if it is accessible/viewable without removing any parts).

Jan 20, 2011 | 12:33 PM

AMG Sleeper

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From: Washington, DC

2005 C55 AMG, 2010 VW GTI (Stage 1)

Quote:

Originally Posted by mrobinso

the tech first removed the engine cover, then unplugged the large rubber tubes, then he unplugged all of the spark plugs, then he screwed off the valve cover (it's gray in color). once that was off, he literally peeled off the gasket, which is like a black or gray rubber lining. Then he washed all the excess oil off cover, let it dry, replaced the gasket, then put it all back together. Total time was less than 40 min probably, and I watched him do it.

Also, he was able to determine which side it was on by looking for excess oil residue on the bottom - make sure they do that first so they know which side to take apart!