When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
New to me 2020 c63s - slight coolant smell; can’t find any evidence of a leak
Hi Everyone; thanks in advance for advice,
I’ve searched and found some threads that indicate I’m not the first to experience this phantom coolant smell. But, as those threads haven’t been active in some time and mostly died without resolution, I’m wondering if there’s new wisdom in the subject.
Ive had the car about a month, have driven a few hundred miles, am driving it most days, have driven long drives annd short drives, and have about 21k miles on the odometer.
sometimes (maybe 1/5th of my drives) I get a slight whiff of coolant smell after a drive. It’s outside the vehicle only. If I pop the hood and get my nose right up near the turbos, or beside the heads and sniff, I can sometimes get the slightest unmistakable scent of coolant mixed in with the other hot smells (I have only done this test when I caught the scent outside, I’ll try to do it more)
It doesn’t smell burnt
doesn’t happen most drives
Coolant level has stayed consistent in the tanks, exactly where it should be; no apparent loss
No codes (stored or pending)
no performance issues
No smoke or anything abnormal in the exhaust
The smell is definitely from the front of the car
no smell in the cabin
I’ve taken a bright flashlight and looked all over for a leak or seep and can’t find anything
no apparent driving pattern or trip characteristics that seem to cause the issue (random)
temperature seems totally normal
anyone got any ideas or suggestions of things to check? Seems a lot of people have had the occasional phantom coolant scent with no loss and mechanics unable to find any issues.
I’ve searched and found some threads that indicate I’m not the first to experience this phantom coolant smell. But, as those threads haven’t been active in some time and mostly died without resolution, I’m wondering if there’s new wisdom in the subject.
Ive had the car about a month, have driven a few hundred miles, am driving it most days, have driven long drives annd short drives, and have about 21k miles on the odometer.
sometimes (maybe 1/5th of my drives) I get a slight whiff of coolant smell after a drive. It’s outside the vehicle only. If I pop the hood and get my nose right up near the turbos, or beside the heads and sniff, I can sometimes get the slightest unmistakable scent of coolant mixed in with the other hot smells (I have only done this test when I caught the scent outside, I’ll try to do it more)
It doesn’t smell burnt
doesn’t happen most drives
Coolant level has stayed consistent in the tanks, exactly where it should be; no apparent loss
No codes (stored or pending)
no performance issues
No smoke or anything abnormal in the exhaust
The smell is definitely from the front of the car
no smell in the cabin
I’ve taken a bright flashlight and looked all over for a leak or seep and can’t find anything
no apparent driving pattern or trip characteristics that seem to cause the issue (random)
temperature seems totally normal
anyone got any ideas or suggestions of things to check? Seems a lot of people have had the occasional phantom coolant scent with no loss and mechanics unable to find any issues.
edit: it’s a coupe, if that matters
I also have a 2020 coupe with 7000k miles and every drive I get that coolant smell but in the rear driver side. I always power wash my car and try to get every area I can but after a long drive the smell is there. My oil change is coming up will request to have car inspected.
It is probably just a little bit of coolant puking out of the overflow reservoir from being a little too full. Most likely nothing to be concerned about. You can check to see if there is a little bit of white residue around the overflow reservoir and that will confirm it for you.
It is probably just a little bit of coolant puking out of the overflow reservoir from being a little too full. Most likely nothing to be concerned about. You can check to see if there is a little bit of white residue around the overflow reservoir and that will confirm it for you.
That was the first thing I checked and everything looked clean. I even checked the AC drain line, shocks for any leaks, and even the inner fender lining hoping no dead animal stained on the fabric material. The smell is almost like a mix of coolant and brake dust. I'm gonna Febreze the inner fender lol
The gasket for the main/big tank does look a little salty and there is a tiny bit of white residue around the base of the fill port. I think I’ll order a new cap.
When you do a coolant top off, do you fill the coolant to the base of the black piece at the top of the white stalk in the tank? My cold coolant level has remained above the half way point to the upper tips of the sensor probes since I got it (ie: JUST below the black piece).
I had the same thing with a very slight smell of coolant when it was parked in the garage, but no leaks whatsoever. I checked my coolant caps for crust and found some on the smaller reservoir by the turbos. Noticed a very small ding in the top of the reservoir and was able to smooth it out and lightly file the top edge flat for an even surface around the whole circumference. So far the smell is better... I guess some vapors might have been escaping, but no liquid?
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
