Brown coolant, but only in the coolant res??

[Commocozy1]

So, I did a little searching and a little reading. But I couldn't find much.

My oil on the dipstick is black and pretty.. My oil in the coolant res is brown... So from what I can tell the oil cooler went bad. But I could really find a lot to back this up in the search.

Does anyone have any ideas? Going to try to do a pressure test tomorrow on the coolant system as well.

BTW this is on a 2003 5 speed 1.8T


I hate cars sometimes!!!

[Lusticles]

black dirty oil mmmmmmm

but you should probably not drive your car and do a coolant flush
it is probably the oil cooler but could also be the headgasket

[Menyahs]

I have this same exact problem. Oil is still good but coolant is nasty. I just ordered all the parts and will hopefully be replacing the oil cooler, doing a coolant flush, and changing the oil this evening. I wasn't able to find a who lot by searching either but the consensus was that my problem was the oil cooler. Hope you are fortunate enough that it's the cooler and the head gasket.

[Commocozy1]

Got everything cleaned out and flushed the whole system today.. Going to drive it a bit tomorrow and see if anything changes.. But so far SO good..

BTW you'll need a 27MM socket to get the nut off the bottom of the oil cooler.

[A4OrlandoB6]

did you mix the pink g12 coolant with any other coolant off the shelves of Autozone like prestone? mixing these is pretty bad. its been discussed a lot lately. they can cause buildups in your coolant flange/lines. are you losing any coolant?

[Menyahs]

Thanks for the info on the socket Commo, You prob just saved me a ton of frustration and agony. They shipped my parts from Tampa to orlando, then back to clearwater, wtf? I will finally get them today, hopefully i'll have as much luck as you did.

[Commocozy1]

Thanks for the info on the socket Commo, You prob just saved me a ton of frustration and agony. They shipped my parts from Tampa to orlando, then back to clearwater, wtf? I will finally get them today, hopefully i'll have as much luck as you did.

I had the same frustration!!! So I figured i'd save you the issues.. The job was pretty easy... Flushing all the bad coolant has to be the hardest part, as it takes so long.. Also good EFFING luck getting the lines off the cooler.. Sweet jesus that took for ever and was a huge PIA..

As for mixing coolant, I personally never did.. Either way everything is fine and danndy now.. I am running 90% water and 10% coolant for a little while till I am sure everything is 100% flushed. All and all I am happy with the results.

[Menyahs]

Done. Indeed huge PIA. I flushed the coolant several times and didn't get all of it There must have been an entire quart of oil that seeped into the coolant. I think its much better for now, I will prob do it again sometime soon. The good news was my oil was perfect for 5500 miles, although i was a bit low as it had seeped into the coolant. Cooler lines: 1st one wasn't bad as it had a normal adjustable clamp. The back on is a total bitch as you have to fully compress with pliers. For the cooler bolt I ended up using your method. I looked at wal-marts and advance and couldn't find a 27mm socket. After a lot of profanity and frustration i did get it, boogered the nut a bit but pretty sure i got it tight enough. Anyone else doing this GET 27mm SOCKET!!!!!!! I will posting pictures later (prob tomorrow) on the thread where is started it all and was given the advice about the oil cooler.