Have a 1998 V70 GLT with 165,000k. I found brown milkly sludge in the coolant reservoir. There is no coolant on the dip stick, or underside of oil cap, and the car runs fine. Could the oil be coming from the radiator or turbo, and is there any way to conclusively find out?

 

It's hard to say, I believe these might have the oil cooler on the pan that goes bad, but does not leak into the motor. If it does not have this cooler, then I would say the radiator.

You should replace all the rubber hoses, thermostat, gaskets, etc. in the cooling system but that's your call. Cascade powder works good as a cleaner, dissolved in hot water 1st.

 

Thanks. I am going to have the radiator checked tomorrow (1st), and then perform a compression check on the cylinders. If these check out, I"ll look at the Turbo.