So I've changed the oil on my rx8 since I've had it, but I got a coupon in the mail for a very cheap oil change from a mazda dealer, so I brought my car in. The service manager said that he was going to put regular oil in because synthetic supposedly eats at the apex seals (or something like that) so I said ok...up until that point I was running synthetic. Now this was about 2 weeks ago, today I decided to check the oil and I noticed two things: 1) it's way overfilled and 2) there's a tan colored foam on the dipstick. I'm really concerned, but at the same time the car runs perfectly fine, there's no noticeable differences in acceleration or idle or really anything...any ideas? I'm certain that before I took it to the mazda dealership that the oil was at the appropriate level and there was no tan colored foam-like substance before. Could the fact that I ran synthetic in it when I "shouldn't have" cause this?


edit: I should also add, I've searched and read a few threads that basically say in our engines overfilling the oil isn't that big of an issue compared to a typical piston engine.

 

If you searched you would have found many threads on the foam in the oil issue and the use of synthetic oil debate. Search some more.