Looking to get some help with a problem I have with my 2009 r55s. I have been getting oil in the coolant, but no coolant in the oil. All cylinders are sitting at 135 psi so ruled out head gasket, at least between cylinders and oil and water jacket. Until today I never had an oil leak. But today something somewhere spewed oil all over on the passenger side of the engine. The whole underside is dripping oil, oil running off of brake caliper and wheel. Back of the car covered in oil. Belts were covered causing alternator to not charge. Had to get towed home. This morning tore into it getvthe cover off so I could see what I was dealing with. Simple green and dawn to get the oil already there off. Now it's all clean and oil free. Started it up to find the suspicious leak. Two hours in and no leaks anywhere. Not a drip. I've seen alot of things in my years working on cars, bikes, tractors. But this takes the cake. Where did the oil come from and why do I have oil in my coolant. Car runs great. Nice and strong, no other issues.

 

The most likely suspect is the oil cooler that is tucked under the exhaust manifold. It is a known failure point.

Not all that mysterious why the oil migrates into the coolant but not vice versa. Peek pressure of the oil is several times that of the coolant.

That the engine failed to leak during what I assume was an idle test suggests that temperature is a factor. The temp controller only allows a very slow rate of temperature increase during warm up, thus it is very likely that during your test the engine never reached full operating temp.

So either the oil cooler itself has failed internally or the seals between it and the block have. Given the car’s age, I would opt for replacing both.

Hope that is of use.

 

If you lost that much oil without re-filling it, your "idle test" may have been a waste of time. I agree with thefarside about the oil cooler being a common problem, however, it's located towards the tranny end of the engine and isn't likely to spray all over the passenger side. Try another idle test after topping off the oil and pulling off the passenger side front wheel and its liner, to expose the belt side of the engine. There's a couple bolts holding the chain guides that might be loose and the front seal could be worn. Maybe get the engine up to normal operating temp before doing all this. You can also get a better look at the valve cover gasket and rear PCV connection. Hopefully your oil spray isn't coming from the dip stick tube, that would indicate a serious crankcase pressure problem.

Let us know what you find?

 

Excellent points, OBF!

 

Thanks for the reply, have since found the culprit. Was just assuming it was engine oil getting in the coolant. Turns out it was transmission fluid from a bad transmission cooler. Started having transmission issue and checked the fluid. 3 quarts low. Filled it back up two weeks later low again. Changed the oil cooler and problem has ceased to be a problem. And the major engine oil spillage was the machining plug in the timing cover behind the crankshaft pulley coming dislodged. A little tappy tap and a drop of jb weld and if is fixed back into place.