2002 A4 Quattro 3.0, 92k miles, noticed the other day white smokefrom the back left of theengine, between air filter-cabing filter and engine. took it to a shop and they told me water pump is leaking but the water pump is in the front by the belt so i dont think is the water pump. what could this be? oil leak? coolant leak?

 

Did you take it to Auto-Zone and run the codes?

 

No Codes, No overheating

 

a water leak is just that so things to look for is coolant lose, is oil leaking onto that side of the exhaust ( oil leak ), does the car run well with no apparent problems? is the CEL on and what are the codes as asked?

 

if it's not overheating then who cares just drive it

haa yeah just kidding there. check your coolant level, if it's low you could possibly have blown a head gasket, but when that happens the smoke usually comesfrom the exhaust and the car overheats, so idk. maybe get your coolant system pressure tested?

 

Blue Smoke = Oil Leak
White Smoke = Coolant Leak
Black Smoke = Rich Fuel Mixture

You're experiencing a coolant leak. This could be bad coolant pipes (my first guess if it is near the rear of the engine), valley pan gasket, head gasket, water pump gasket or water pump unit. Check the coolant carrying hoses that lead into your firewall. These carry the warm coolant into the heater core inside the car for your warm air. If they are loose, cracked or have bad o-rings you might be leaking.

Never ignore a coolant leak. You guys are freaking crazy if you do.

 

do we ignore a coolant leak?? ^^ that's the first thing I looked at and that's why I asked if the car was running well, an oil leak from the valve cover dripping onto the exhaust would plume a white(ash) smoke till it got serious, through the exhaust pipe it would be blue

 

I'm thinking you mean right rear unless they have really changed things around. Check the rear of the valve cover to see if your crankcase vent hose isn't broken offor cracked.

 

The car is running fine, just lately everytimeI stop theengine smokes from the back. I could try get some oil and coolant, use a dropper and drop some on a hot metal see which one smells like it and what color smoke, it will tell me if is coolant or oil. But I still wont know where the leak is coming from, I'm going to have to take off the air filter box and look, its a pretty tight space. The shop did add some coolant because it was low.

 

Kind of tells you what might be leaking.