Mystery Oil Leak Conundrum

I have a 2003 Saturn Vue, with almost 114,000 miles on it. This past year I have had several repairs (broken water pump and timing belt replaced in Feb), and in July I had leaking head gaskets which mixed with the coolant and made a big mess of my engine. I took it to an independent mechanic after it overheated heated and broke down, which is when the problem was discovered. After 2 weeks of work, including the head gaskets going to a machinist, the radiator being replaced and the engine being flushed several times (not to mention $3000!), I finally got the car back.

This past Tuesday I took the car into the Saturn dealer for an oil change and to check the engine because the oil light had flashed on and off and the car had started making a knocking noise. When the tech checked the oil it was completely dry and it looked like the radiator fluid had been replaced with oil! The mechanic at Saturn thought the last guys to work on the car had messed up and put the oil in the wrong place, but since I had been driving for about 6 weeks that didn’t make sense.

I had the car towed to the original mechanic, assuming they had either missed something or done something wrong with the repair, but they can find nothing mechanically wrong with the car. They also said it looks like someone drained the oil and poured it in with the radiator fluid - but no one has worked on the car since the repairs in July. At this point I don’t know what to think, so I thought I would check with the Car Talk community to see if anyone has heard of anything like this, if the mechanic is trying to cover up a mistake, or if it could be a case of foul play… Any ideas??? The car is still in the shop and I am supposed to be driving it from San Diego to Monterey in a couple days.


We have heard of this and a lot more. It’s easy to get things wrong. I recommend a rented car for this trip because you can’t possibly have a lot of confidence in the Vue. I have gone to and from San Diego from the Lompoc area in a 2003 Vue and I enjoyed the trips. I liked to stop at Coco’s in Calabasas, don’t take a wrong turn. As far as the vue goes, I would sell it, of course. I didn’t like the seats or the way it would get sneaky and try to drive off the road. I never drove it when I was tired because of that feature. I put 30,000 miles on it and quit after that. I never could figure out where I was going in Montereythe one time I went there. Nice place.

If you are contemplating a long drive in a car that supposedly had NO oil left in the crankcase, then I would suggest that you reconsider this plan.

If you really drove it to the point of zero oil or very little oil, and if the engine was making knocking noises, the engine is undoubtedly toast at this point, and cannot be relied to take you as far as the supermarket without a catastrophic failure. That type of situation would be inconvenient in your own environs, but it would be REALLY inconvenient when the engine suddenly seizes up about 200 miles from home.

As was already said, you should rent a vehicle for this trip while your trusted (??) mechanic sorts things out. At this point, I am leaning toward the possibility that your engine blew a head gasket, but with the information that you have provided, my guess is just as likely to be wrong as it is to be right.

In any event, the engine on that vehicle should not be started at this point, because even starting the engine is likely to inflict more damage on it than has already been done.

Please post back with the final diagnosis by your mechanic!

If this engine has an engine oil cooler, look into the possibility that the cooler has sprung a leak and is pumping pressurized oil into the cooling system. The oil pressure would be 20-60 psi while the cooling system would be less than 15 psi.

This may be a simple fix, i.e. a part replacement; clean up of the cooling system; and oil change just to flush out any coolant that got mixed with the oil.