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'98 C280 Water-in-Oil Problem(?)

2891 Views 13 Replies 6 Participants Last post by  lugnut2099
So, crap. Went to check my oil this afternoon, saw a bit of the signs of water in the oil. Opened the filler cap, as nasty-looking as you could get. First thoughts were of course that it's screwed, but then I got to thinking - it runs great, it doesn't knock, it doesn't get hot, it doesn't smoke, the oil/coolant levels don't seem to be off, etc. Then I started googling stuff and found a lot of mentions of M112 engines with this issue in cold weather/short trips caused merely by condensation and a poor design and now I'm convinced this must be what's happening, but not sure. The oil itself doesn't seem milky or anything, just a tell-tale sign of something askew. The dipstick doesn't have any of the "peanut butter" goo on it that you see under the cap.

Anyway, it had admittedly probably been a month since I'd looked at the oil by stick, but it was fine then. I'd checked via the dashboard method last week and got an "OK." These past couple weeks though, it's been pretty damn cold (below freezing) in the mornings/nights, and the car does get used for a lot of short trips. Now while *I* let the thing warm up, neither my wife nor my friend who lives us seem to understand how to do this. Incidentally during these past couple cold weeks, I've let our friend use it in the morning to take her kids to school a mile or two away, since her car has no heat and a bad power steering fluid leak. It's still very cold then, she goes there and back, and then the car sits for around another three hours before I go to work.

My drive to work is about 16 miles, so really the engine is probably *just* getting to the normal temp at that point (in this cold weather), I'm thinking, right? From there, the car generally sits for 8 hours again, and it's night by the time I get home and thus, cold as hell again. Drive the 16 miles home, car gets shut off, usually sits 'til the next morning or maybe a very short trip to the store inbetween.

Soooo.... does this sound to you guys like the condensation issue? It seems that way to me, but I'm far from mechanically inclined and might just be wishful thinking. I'm just betting with the cold snap the thing's probably never quite getting warm enough to burn it off, especially after reading how common this seems to be, but I dunno. If it was head gasket/head/block I'd think I'd surely be experiencing some kind of issue with the performance or some kind of dashboard error light triggered or something, but it's just fine seemingly and even though ever since I've been *looking* for something wrong (I'm a pessimist by nature, heh), I still can't think of any unusual symptoms... other than the nasty gunk under the cap. I'm going to go ahead and change oil/filter this weekend, but I almost have to wonder if I might be wasting money/time doing so.
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lugnut, have you come across this thread:

Do your deposits look worse (if that's even possible) than those of the threadstarter? You don't have to read through all the pages, by the way: in the end, nothing was wrong with his engine, as many predicted (although some others vigorously argued his head gasket was blown...).

If you still worry, why don't you take your car on an extended joyride--1-2 hours on the highway--and see what happens.
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