There's a sweet coolant smell emanating from my engine bay every time I drive for a bit and park. For the life of me, I cannot find any coolant drips on the floor, nor white residue underneath my hood to signal an exterior leak.

I searched previous posts and checked the following:

milky oil to signal a blown headgasket - None, oil is the normal color and texture
white residue under the oil cap - None, oil cap comes off clean
white residue under the hood - None, hood is clean
worn radiator cap - Radiator cap seal looks good, I just replaced it 30k miles ago

It's about time for me to do a complete coolant/antifreeze drain and fill and I'd like to fix this if possible before I do it. One thing I have yet to try is bleeding the system, but since I actually smell coolant in the engine bay does that necessarily signal an exterior leak? OR does having air in the system contribute to the burning of coolant without leaving a trace?

TIA

 

there are kits that you hook up to to your radiator cap and run your car, they test for hydrocarbons in the cooling system. This indicates that the combustion is leaking into the cooling system. If your burning coolant, this test will confirm that.

 

Check your rad, top and bottom plastic end caps, it is very common for them to leak where rad core is "crimped" to the end caps, it can be very hard to find. 94

 

Good tip, I have the same smell and cannot see leaks anywhere, hoses are all new as is the thermostat after I pulled the head and had it milled I replaced the HG and installed new ARP studs. I will check the radiator since this is a car with 180K miles.