Hi I have a 1998 volvo C70 with 110k kilos, over the last year I have noticed that the water resevour has a mixture of water and oil in it . The intercooler was worked on about a year ago and since then I have had the above problem. Fortunately I dont have water in the oil and the oil is black and the correct color.(dipstick and filler cap). I seem to be loosing a small amount of oil and gaining it in the reservour. otherwise temp and performance are fine.Do you think I have a leak in the intercooler? maybe a bad weld. thks

 

Is your car a auto.


If so you have a oil cooler for the transmission within the radiator matrix. I would check the auto fluid level and make sure its not going up.

 

Black colored oil indicates that you need to change the oil and filter also.
Moderate discoloration is ok after a period naturally.

 

You may have a bad radiator. You may be able to have it pressure tested to see if the oil side is leaking into the coolant.

There is also a chance that you have a bad head gasket, mixing oil into the coolant chamber. This is rare but possible. You may have a mechanic do a compression leak down test to verify this.

 

Hi guys Thks for your advice. It looks as if it could be a number of things, non of which can be tested in the car. The gearbox oil is clean and up to the mark only (so not the G/box oilcooler). There is no oil in the water on the dipstick or filler cap.,and the car runs great therefor I doubt if it is the cylinder head gasket.
Fact is I,m loosing a small amount of engine oil over a long period of time with associated "Cafe au lait" coloured water in the resevoir. Another suggestion is, Is the turbo water cooled?? as well as oilcooled??I tend to think it is a radiator/engine oil cooler contamination. Whichever way its going to be a costly exercise to find which of the above is the culprit. would appreciate any more ideas as we learn as we go Thanks .Alan

 

Turbo is oil lubricated and coolant cooled.

 

I guess I am a bit late here. Did you get the problem sorted?

My suggestion would be to drain the coolant no just fill up fresh one. It's $15 at a parts store (do NOT get their generic brand). Keep a note on the color and level on a daily basis. You will see know how bad the problem is. Loosing some oil over 3000 miles or so is ok. My 1998 with 298k miles goes through about 3/4th quart between oil changes.

I also recommend that you get a pressure test done. If you want to save some money, get a "loaner" coolant leak tester from advance auto/auto zone. Instructions come with it and are very straightforward. Mixing coolant and oil can lead to disastrous failure and for the age and mileage of your car probably resulting in junking it.

Post back with your results and someone can guide you further.

 

Hi Thanks for your suggestion. I,m going to drain the radiator flush and refill with anti feeeze/water ,then monitor it for a while. I,m not familiar with a pressure tester that can be used in situ on the car (maybe its not available here in South Africa), as radiator specialists say the rad has to come out to be pressure tested. Meanwhile the car is running like a dream. Thanks

 

Whoops. Didn't realize you were in South Africa. But here in the US, you can get a pressure test kit. You can YouTube it and see what I am saying. It's pretty simple and yes you can do it by yourself on your street/driveway/garage. Just do it when the car is cool. The leaks will "pop up" as such and then you can decide what to do.

Also while changing your coolant, creep down under your car (secured on jack stands of course) and see if you can see if the transmissions cooler line which runs into the radiator - these are on the passenger side in Left hand drive cars if I remember correctly - is leaking. Also check if the inter cooler is leaking. The leak test checks the whole cooling system and not just the radiator.

I would avoid taking long distance trips until you can pin point the source. Oil and coolant mixing is never good and the 5 cylinder Volvo engines can be very finicky.