Avdwaal1

2006 Audi A8 base, 145k miles. I have a sweet smell (coolant?) inside the car, it seems to be there most of the time but sometimes the smell is stronger, after I parked my car for about 1 hour and then started it the smell seems stronger. BTW: Several months ago I replaced the timing belt, water pump and thermostat. I did not use any sealant on the water pump, just the gasket. I have been reading here on the forum about possible causes but haven't found much useful info yet. I have also noticed white smoke coming from the car, probably from the catalytic converter?

help!
Arthur

Jack88

Sweet usually indicates coolant. Coolant will burn and produce white smoke out of the exhaust if you have a head gasket leak. Is the white smoke under the hood or out the exhaust?

tenspeed

Sorry to say that it sounds like a heater core leak. Not a fun job on any car.

TSHong

Unfortunately +1

Avdwaal1

it seems to come from the middle of the car, not the exhaust.

Avdwaal1

Anyone here who has done a heater core replacement?

Mister Bally

I have not had to replace them (note how I said "them") on my 2004 D3. There are two, one for the driver, the other for passenger side of the car. The procedure looks simple for the passenger side and not much worse for the driver (for driver side, the accelerator and brake pedal contraption has to be removed).

Pretty straightforward procedure per the Bentley service manual. I'd actually look carefully for a leaky rubber hose or possible broken/loose hose clamp on or near those heater cores.

Good luck.

Jack88

Okay, smoke from the middle of the car means a leak onto the exhaust, relatively good news. White smoke out the exhaust is really bad. Keep an eye on your coolant level.

MP4.2+6.0

+1 on suggestion to check the connection hoses carefully. Take off the plenum cover, clean out all the leaf crap and other junk that will be in there usually, and look carefully at the hose connections over on the (U.S.) passenger side. There are a fair number, compounded by that electronic heater valve next to the heater assembly. If you find pink residue on things, that is burned off coolant from a physical leak. Much easier to fix than starting to get into the heater cores.

Also, be sure to confirm you are actually even losing coolant. If not obvious over the days or a week, mark the coolant overflow bottle fluid level when it is cold. Then check it after a few days. If it changed you have an issue. If no change, you are smelling something else.

Avdwaal1

[EDITED]
I checked the hoses carefully, don't see any leaks. Earlier this week, I was driving a bit fast for 15 mins, then parked my car on the driveway which has a slight incline. When i came back 10 mins later i noticed quite a bit of coolant under the car. Then I remembered some months ago the coolant in the expansion tank was boiling and overflowing, it happened driving uphill.

-faulty thermostat (although I replaced it 6 months ago)
-Tank cap
-Oil cooler leaking
-Head gasket
-too much Bar's leak
[UPDATE]
-clogged radiator; the fans seem to be running all the time [UPDATE] I just checked the upper and lower radiator hoses, upper one is really hot, lower one is cold/lukewarm, engine coolant temp according to vagcom was 90c at this time


thanks,
Arthur