n52audi18t

There is also what looks like sludge, but I guess it's oil in my overflow tank, is it a bad head gasket or a crack in the head itself, is there anywhere else where oil and water can swap?

Yippers®

More likely the oil cooler.

n52audi18t

I didn't know there was even an oil cooler on the car, where is it

JAFO

<center><img src="http://pictureposter.audiworld.com/39415/1.8t_engine_with_descriptions1.jpg"></center><p>square silver box.

Yippers®

fluids to mix.

n52audi18t

thanks

n52audi18t

it shouldn't get any worse, or do i have to replace the unit?

JAFO

oil change won't cause this on it's own. lack of maintainance on the cooling system causes the cooler to corrode. changing the filter was probibly the final insult. unit will need to be replaced and coolant system flushed!

Mighty Highlights

The oil cooler is what the filter screws onto. To fix <A HREF="https://forums.audiworld.com/oz/msgs/2048.phtml"> LOOK HERE </A>

If you keep driving on the busted oil cooler then all your oil will drain into the coolant system, the coolant system will over flow. Then you will be left with no more oil in your engine. eeek. Im surprised your engine/oil light hasn't already come on.

Its not an expensive part.

n52audi18t

that's why I thought it was just a bad seal on the new oil filter when he said it was the cooler, and I check my oil almost every day so i'm not to worried about an engine with no oil, but it did take about 4mm on the dipstick when it first happened