PeachParts Mercedes-Benz Forum - View Single Post

GlennCraven · #14 11-02-2005, 11:45 AM

All right ... tell me how stupid I am. Or something.

Now I wonder whether I really have much of an oil leak at all! (OK, some, but not a lot.)

I sprayed the engine liberally with Gunk-brand degreaser. Hosed it off. Got it pretty clean for the most part; very few additional gunky spots.

With the engine cool (sat overnight in the driveway) and sitting about at the bottom of the "safe" zone on the dipstick, I added a quart of Rotella that brought it up to the top. Then I backed the car out into the only available sunny spot on our acre and let the engine run a bit.

I looked down from the top; no apparent major leaks.

I got underneath; no apparent major leaks.

One of the two big stain spots was right around the rim of the oil pan, dripping off pretty much the whole right side and front edge of the lower pan. That pan is now very clean (for a 216K-mile car) and there's not a drip. None. I put a clean rag underneath to catch any drips that came down, ran the engine about three minutes, cut if off and let it sit for 10 minutes, not a drop of oil.

Back near the passenger firewall, where there was such a flood, I can't see dripping at all. I didn't put anything under it to catch, so it's possible a drop or two went down, but nowhere near the constant stream I'd experienced before.

Here's what I think: At least in part overfilling.

When I test-drove the car, I took it about two miles down a service road and parked it in an empty business lot and did a walkaround. I looked under the hood while it was running, then shut off the engine and checked the oil. It was at the top notch on the dipstick.

When I paid for and returned the car to where I was to meet my wife, it was spewing oil. ... When I've filled it up to that point on the dipstick again after getting the car home, it spews.

I do realize that you should check oil while cool and on the flat. As the manual says, checking the oil right after the engine has run can give a faulty reading because some oil might remain in the upper portions of the engine. But I didn't think it would make potentially this much difference.

After filling to the top in the driveway today, running the car at most five minutes, then shutting it off, the dipstick showed a half-quart low. And when the car sat for five minutes, still a bit low. Sitting 20 minutes, it's now up to the midpoint on the stick. I'll bet when I get back outside after writing this, it'll be back to the top of the proper range on the dipstick.

I'm really wondering whether the car was overfilled with oil when I bought it, resulting in me freaking out at the purge of oil (from where all it came, I don't know) and thus I overfilled it to compensate for all that I seemed to be losing. Especially because it seems to take 20 or 30 minutes for the oil to work its way back into the lower pan from the upper parts of the engine after parking.

Now, I do know that there's a seepy-sort of leak at the valve cover. That's readily apparent. But I really wonder whether the oil-puking I've experienced was from overfilling.

What do y'all think?