I've seen a couple of post regarding this question and I've picked up a few things from them but I have a my A4 has a few symptoms that stand out in my mind. First I'll start with the specs. I know this is long winded but I really like my Audi.

99' A4 1.8 FT with around 180k miles.

I've replaced a lot on this car but here is a list of things recently replaced in order.

I replaced the original oil cooler around 3 years ago but with a cheap one I found online. I now get my parts strictly from ECS because I feel I can trust them to sell decent parts and frankly they help point you in the right direction should you need it.

My original K03 went bad a while ago and I recently had that replaced with a new K03. I also had the CAT replaced since I'm sure it was a little clogged since my car was burning oil due to the bad turbo. This is my work car and I drive quite a bit for work so that is why I replaced with the K03 instead of upgrading to the K04. With 180k miles I'm just trying to keep it running not upgrade. Anyway once the turbo and cat were replaced the car was more powerful than the day I bought it. The car ran great although did misfire and stutter a bit when I stomped on the gas.

This made me think I should do a tune up and replace some other parts that I had neglected after the turbo was replaced. New coil packs and spark plugs took care of the misfiring and I also replaced the thermostat because mine was stuck open and the car never warmed up to where it should and the heater wasn't as hot as it was before. Lastly I replaced the cam seals and the valve cover gasket. I replaced the valve cover a year ago but neglected the cam seals I decided to do the valve cover again with the cam seals since it's cheap and I might as well since I was in there.

Here's where I got stumped. Once I replaced the thermostat the car got up to normal temp and the heater was blowing hot air again. All looked well so I decided to let it idle for a while and think about how awesome my car was again. After 20 minutes I noticed white smoke coming from the exhuast and water dripping from the tail pipe. I know most people jump right into a bad head gasket but I'm really hoping it's not because I'm going to get rid of the car if so (and I love this car). I also noticed the valves clicking which I'm assuming was because the oil was diluted with coolant and when I pulled the dipstick out it had bubbles on the end of it. I drained the coolant to see if the oil was getting in and it didn't seem that it was although I didn't test it.

I haven't done a pressure test but here is why I'm thinking that it's the oil cooler and not the head gasket. First, when I went out to start it again after letting it sit it wasn't smoking anymore and there was no clicking from the engine. It also doesn't misfire and doesn't overheat or run rough which are the typical signs of a bad head gasket. It seems though that once the car gets warm enough that the thermostat opens up is when it starts with the white smoke and the dripping tail pipe leading me to believe it is the oil cooler.

Is there anything else I should look for to determine it's one or the other? I think I'm going to replace the oil cooler again since it's cheap and if it's not the problem then assume it is the head gasket. Is there anything else that would cause these symptoms beside the gasket or oil cooler? Any thoughts or advice would be greatly appreciated.

 

might do an oil change just to see what color the oil is... if it is milky then you know what id up