I have been noticing a very slight coolant smell from the front of the car when it’s hot after I park in the garage. No leaks anywhere on the garage floor and I couldn’t see any signs in the engine bay. The reservoirs look like they are at their correct levels and the car doesn’t run hot at all.
I did a search and there are a ton of posts on this but no real answers.
Anyone else have this or know of a possible answer?
Car is a 16 with 4K miles
The odor of antifreeze when the engine/cooling system is hot is almost certainly because of a leak.
Had one car that on a hot day I smelled anti-freeze. Got car into dealer service and tech put car on lift and very clearly at the water pump there was coolant leak sign, and sign it had been leaking there for some time. I'm pretty good about looking for any signs of a leak under my cars when I walk up to them and I never saw any leak sign on the ground under the car.
Yet, this same car "fooled" me when after I had the radiators replaced upon using the car -- essentially giving it a shake down test drive before heading out on a 2K mile drive back home -- I smelled anti-freeze. Took the car back to the dealer service department. Tech checked over the car and reported no leaks. He did admit he spilled some coolant when refilling the system. He rinsed the engine thoroughly and started the engine and got it to temperature and there was no smell. I took the car and after some more shake down testing deemed the car ok and drove it home with no problems.
My advice is do a hot pressure test.
With the engine dead cold top up the coolant level using distilled water. Do not over fill the cooling system but bring the level up closer to the max line. The less air space in the system the better.
Be sure the cap is on properly.
Turn off the A/C.
Drive car around town -- my experience this gets the engine -- coolant and oil -- hotter quicker and just hotter than a drive at freeway speeds -- until the radiator fan comes on due to the coolant temperature reaching the fan on trigger temperature. With my Hellcat this appeared to be 216F.
Go home.
On your driveway raise RPMs to ~1K and hold until the radiator fan comes on. When it does shut off engine.
Raise hood.
Wait.
The heat load of the engine will raise coolant temperature and pressure and if there is a leak almost certainly you'll know it.
Most likely the leak will be from the water pump seals, but I had one car with a coolant tank that had developed a crack along the bottom of the plastic tank at the mold seam.
Another time the coolant tank cap proved to be defective. It allowed pressure to escape at too low a pressure. With this leak I did not smell anti-freeze because only water vapor escaped. But I did spot some drops of water on the trunk lid above the coolant cap. I tented the cap with aluminum foil and after a few minutes after I shut off the hot engine water had condensed under the foil. A new cap put a stop to that.
