Matts2015c300

I have a 2015 c300 4matic sport with 30k on the clock that has produced an odor of burning coolant from the engine bay. The smell is only noticeable with the windows open, otherwise, the smell does not make it inside the cabin. My garage, on the other hand, smells rather strong especially after a spitited highway drive. The car is in the shop right now and no leaks have been identified. I am being told that the smell is normal for this engine. Am I being sold a line or are others experiencing the same smell. Also, I had the wrist pin repair done and I am not sure if I noticed it then because I became hypersensitive or if it actually started after the repair. Any input is appreciated.

MASSC450

No, a burning coolant smell is not "normal", and it's a good guess it occurred after you had your motor worked for the wrist pin issue.

Your car is still under warranty, correct? If so, keep bringing it back until they fix it...or try another Mercedes dealership after calling Mercedes customer care to register a complaint.

Matts2015c300

this is dealer #2 trip #2 and the dealership has been great. I have been to three different dealerships and this is the first one providing an experience I would expect with the Mercedes brand. I should note that I had the overflow reservoir replaced as well as a new cap put on the turbo reservoir but the smell persists. For those repairs there was a visible leak found. Now they can't find any leaks. I called my SA and they are going to investigate the smell again.

Mr. J

If it's losing enough coolant to be able to smell it, then there should be some noticeable reduction coolant level. Small leaks can be tricky to find. It can take a while before it will leave enough residue to be visible. The usual suspects are coolant hose attachment points especially hose clamps and nipples. A little bit of white residue usually indicates the location of the leak.

scooby24

I'm also smelling coolant on mine. Took it to the dealer and they couldn't find a leak. They said they pressure tested the coolant system but then stumbled when I asked them if they'd considered checking the intercooler. Eventually said they did but I'm betting not. Smell it after every drive. Please let me know what you find.

Matts2015c300

I am being told that the smell is normal and there is no leak. Can any c300 owners confirm if they have no odor from their engines? I am being told that the smell is normal for the 2.0L turbo. Funny I never noticed it early on..... btw the car is back in the shop after it was returned with crazy brake vibration. I plan on bringing up the smell again if I can get a bit more info about others experiences.

dieseldoc

I have same engine in my GLC. No smell.

AAN

My car (2015 c300) have this smell from the day one. I have never related it to the coolant, rather it smells to me of hot or burning wire. I can smell it in my garage, after even a short run. My dealership service looked at it a few times and they don't think it is anything to be worried about, so, nothing was done. But who knows?