im losing oil and it's going into my coolant reservoir. what could the problem be?


Asked by Aug 22, 2013 at 10:35 PM about the 2002 Buick Rendezvous CX FWD

Question type: Maintenance & Repair

I have an 02 rendezvous that is running perfectly. It doesn't heat up or blow smoke, no
signs of any problems. But after i got my oil changed i did notice that my coolant reservoir
was over flowing with milky looking liquid. My oil is being is being leaked to my coolant
reservoir. There is NO milky substance in the radiator or in the oil it just in the coolant. I
have no idea how it could be getting there. PLEASE HELP.

5 Answers


Typical culprit is failed headgasket. If the oil is in your reservior, it's in the radiator/whole cooling system. Don't drive it anymore till you get it fixed. You'll have to have both the oil and coolant drained when doing the repairs.

5 of 5 people found this helpful.

I have a screeching/squeaking sound coming from my car when i press the gas, but as soon as i press the breaks it stops. What can this be?

2 of 2 people found this helpful.

Don't do anything about your head gasket until you first check out the oil cooler I had a 2003 Buick Rendevous with the 3.5ltr engine, with the very same sypmtoms. (oil in the coolant) Fortunately, I was tipped off that it might be the oil cooler and that was what it was. On the 3.4 ltr, the oil cooler is what your oil filter threads onto in the front of the engine. To access it, I did have to remove the raidiator and a few other things, but it was a great deal easier than replacing head gaskets only to find out that it was the oil cooler. The cooler did cost me a couple hundred dollars, but it did fix the problem. So grateful to the guy who tipped me off, that I thought I would take a moment to save someone else like he saved me.

4 of 4 people found this helpful.

I have a similar issue, but I had a mechanic report that it was transmission fluid leaking from the radiator internal transmission fluid cooler. is there a difference between oil cooler and transmission cooler, or are these one and the same?

1 of 1 people found this helpful.

They are the one in the same. Just easier to say "oil Cooler" then the other. Transmission Oil Cooler.

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