Hello I Just purchased A 2003 a4 (1.8T) with 70,000 miles on it. When I purchased the car it smelled like some orange cleaner but after a day or so I noticed a coolant smell coming through the vents when the heats on. If I put the heater on recirculate no smell comes out. The outside of the car around the hood smell like antifreeze but when I open the hood I cant smell anything. I cannot find any leaks and my coolant level has been fine ever since I bought it. The smell is driving me nuts.

 

Its leaking somewhere, probably the coolant flange on the back of the head, or if its a 3.0L, the nipple on the coolant crossover pipe.

 

It's a 1.8t.

 

When I changed my thermostat, the coolant was spilled a bit around on the engine block. I wiped it off with rugs and paper towels, but I still had coolant smell for days after that. I't fine now.

Just keep checking the coolant level but make sure you compare apple to apple, i.e. check it in the morning, with cold engine.

 

Like auditech says, check behind your engine for crusted coolant. It might be leaking.

 

I looked behind the engine and I see nothing leaking. there is some dirt n-stuff on the transmission but nothing that would indicate antifreeze. I sniffed around and I smelled coolant by the reservoir cap but didnt see any leaking. I untwisted the cap and it hissed which I assume is normal. Do you think it could be a heater core leak? I dont see how its possible because when I put the heat on recirculate or vent at highway speed the smell disappears. MAN this is frustrating.

 

It could be, look around your floormats for leaks or evidence of leaks. Keep an eye on that reservoir too; if it goes low top it off with G12.

 

Floor boards are dry with no coolant smell.

 

Then is most likely your cabin air filter, is like 20 bucks, change it to see if problem persists.

 

I bet you money its leaking..............just wait it will get bigger