My car has a slight coolant smell when it gets hot. No leaks, drips whatsoever, and I’m not loosing coolant anywhere. I just can’t figure out why I detect a slight coolant smell after it gets warmed up. Maybe I’ll swap out the radiator cap. I don’t know what else it can be coming from. I don’t have a heater core, it was bypassed a long time ago. Car doesn’t overheat. Runs at about 190* with AC on when it 110* outside. Using a dual a Contour type fan. Thanks
Engine Slight coolant smell
- Thread starter ggradtech
- Start date
If you have a coolant odor you have a leak. It is seeping someplace, it is just not enough yet to effect the level.
suspected areas are corners of lower intake, hoses at the egr valve or the egr valve itself, timing cover at the water jacket, freeze plugs, these are not all the places.
A leak may appear like white runs if it is very small and dry.
suspected areas are corners of lower intake, hoses at the egr valve or the egr valve itself, timing cover at the water jacket, freeze plugs, these are not all the places.
A leak may appear like white runs if it is very small and dry.
I looked everywhere. No trace of any kind that I can see. If I “sniff“ the radiator neck/ cap area, it does slightly smell like coolant. Maybe a new cap and see if it helps?
A coolant pressure test may make short time of finding your leak.
91GTstroked
15 Year Member
- Jun 14, 2007
- 502
- 274
- 93
What about having the stock coolant reservoir? The top of the stock reservoir is open in case it overflows. Can't that create a coolant smell being it's open?
You should not smell coolant unless it is leaking. Just a drop or two on a hot surface will stink for awhile.
Still not finding any evidence of a leak. No white drips or puddles. The overflow is an aftermarket type, and it looks good and seals well. The rad cap does have a slight hot coolant odor. I should at least change that out I think.
The coolant leak down test will pressurize the system, check your cap and everything else without the system being hot. I got a tester from Amazon, but Advance Auto usually has one for check out. It can make short work of finding little leaks like this, and was worth the money!
Habu135
5 Year Member
91TwighlightGT
20+ Year Stangneter 
He said he doesn't have a heater core.
I'd definitely pressure test the system. If you are smelling it, I would be more apt to think it would be in a hot area on the engine itself or contacting the exhaust system.
Habu135
5 Year Member
When my thermostat housing first started to go, I realized it from the smell, then I found the “oily spray“ on the underside of the hood.
No real leak or puddle anywhere else at first.
I guess only as the pressure built, the leak was small enough causing the spray to appear.
No real leak or puddle anywhere else at first.
I guess only as the pressure built, the leak was small enough causing the spray to appear.
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