i just purchased a 2001 S4 about a month ago and i have a few issues with coolant. It seems to be using up coolant from something, i did notie if you get under the car it seems to have a small leak from somewhere and you can smell it coming from the engine bay but it is so crammed its hard to actually figure out where its coming from. is the any place that is a comon spot for coolant leaks? also, i was reading another post and they mentioned that if they ran the car for awhile then shut it off for a short period or time, and turned it back on it would read alittle warm, but would cool down right away. mine seems to be doing that but i didnt think much of it because the fans have shut off and it makes sense that it would get alittle warmer, is this really a problem? any help would be great.

 

2 places it likes to loose coolant.

1. the expansion tank, this is where you put coolant, it gets old & crusty, get tiny splits in it, when under pressure, coolant comes of out the splits. This is hard to notice, due to the tank having a double wall. If yours is crusty, just change it. It should be a egg shell white color.

2. the Afterrun pump. This cools the turbo's by pumping coolant through them. It's under the intake manifold. If you remove your engine covers, & get a flash light, you can see if over towards the passenger side. If it is leaking, you will see pinkish crusty stuff around in that area.

 

I have a similar type of problem but no smells of coolant. Coolant goes down when cool to Min in the expansion tank. Whenever I fill it up to Max, it takes a week or so to go back down. Fortunately, so far, it doesn't go below that.

Temp needle stays slap bang in the middle.

Do these expansion tanks have an overflow outlet? Where is it located?

 

ok thanks alot, i dont think its the exspansion tank cause i have looked at that. ill look into the afterrun pump though. i had the car on a lift for inspection and i noticed dried coolant underneath so its def leaking and not burning it through the motor, which is good. but ill def get underneath and take those covers off and take a peak. What exactly does this afterrun pump look like, or will i notice it right away? also, what the cost on a new one? i do all my on work, so worry about that cost. thanks

 

The pump is under intake manifold, on the passenger side. If it is the cause, you will see pink gunk all over it.

 

I had to change mine 2 years ago for the same reasons as yours. It'sa PITA job if you don't
take off the intake but it can be done (i did it). You remove all the dishes over the intake, you take off
the TB & TBB, then you have too use long screw driver and/or your fingers to slide it out/in. Works better with small hands. Prepare yourself for some hands scraches. If you want to get intake out it will be time consuming. The pump is sold around 180-200 $ ECSTuning sold some i beleave.

Good luck !

 

The overflow is under the cap on the bottom of the tank. The cap has a pressure release that lets coolant come up and over the perimeter, then back down through a small tube.