George Boss

I just changed the oil on the car (89 951) and the wrench called me over with those dreaded 6 words : I think you better see this
There was engine oil on the undercarriage, and it seems to have splattered on the various pulleys and belts.
Now, I've never had this problem, and I suspect the culprit is the thinner grade oil I recently put in (less than 200 miles). I always used Mobile 1 synthetic 15-50 for the past 8 years, and never had a problem. I decided to try the Mobile 1 synthetic 5-50 at the last oil change, and, in addition to letting the engine run hotter than usual, this.
The question is, do you guys think it's the oil (I just ditched the 5-50 and put in 10-60 synthetic today) getting around an admitedly old seal, or is it the seal? And if it is, which one and what is it called? Any ideas of how much to fix it, assuming it's the seal?

StoogeMoe

There's an ongoing debate whether different grade oils cause engine leaks. I think you just ran out of time on the seal.

You're going to have to be more specific where it is leaking. There are about 50 places where a leak can occur. Some easy to fix, and others very painful. Need more info.

____________________________________
1986 944 NA - Guards Red - 90k miles
1983 944 NA - Platinum metallic - beginning a new life
1985.1 944 NA - Guards Red - donor car
1984 911 Carrera Coupe - Guards Red (gone, but not forgotten)
"If you're not living on the edge, you're not living"

George Boss

I just got a quick look at it, but the most accumulated dried oil/crud seems to be from the most bottomost pulley. Any hints on how to more accurately zero in on the possible location?

StoogeMoe

Is that what your mechanic pointed to? If so, it's most likely the crank seal and the associated oil pump drive gear. Or the oil pan gasket. I would clean off the gunk as best as possible using brake cleaner and rags. Get it as clean and dry as possible. Then start the engine and see if oil starts collecting there again. If not, it may be a slow leak that you may be able to live with.

You can also lay a big piece of white paper under the engine to help locate approximately where the leak is coming from and how bad your leak is.

____________________________________
1986 944 NA - Guards Red - 90k miles
1983 944 NA - Platinum metallic - beginning a new life
1985.1 944 NA - Guards Red - donor car
1984 911 Carrera Coupe - Guards Red (gone, but not forgotten)
"If you're not living on the edge, you're not living"

George Boss

Already laid a white sheet (in secret of course....my wife is married) under the car last night. This morning, there was no oil on it. I'm beginning to believe it might have just been the super hot thin oil getting around the seal. I'll try the same thing tonight and let you know.
BTW, if it is the crank seal and the oil pump drive gear, is it labour intensive to replace?

Chris_924s

you can pressure wash the area to clean it - then watch closely for oil dripping.

Check your manual, or www.clarks-garage.com to see if replacing the crank seal is a task you'll feel comortable with.