Oil leak question

toddu · 10:30 AM

I've just recently developed (or more than likely an existing leak worsened) a leak that is dripping down onto the exhaust line that runs from the right heat exchanger over to the front muffler. This is occuring fairly close to the heat exchanger (where the 3 pipes begin to join). If memory serves me, this would be close to the oil cooler (can't remember if that would be just below, and a little behind, etc).

I haven't jacked the car up to look yet, and my ADD won't let me wait

, anyone have thoughts of what might be leaking? I suppose it could be oil cooler gaskets. Do any of the oil lines run up near there? The hose comming off the cooler doesn't actually carry oil does it?

I'm hoping I can fix whatever it is with motor in car. Dripping onto the exhaust creates some good smoke at times.

Todd

rusnak · 07-09-2008, 10:33 AM

do you have an SC or a turbo?

It sounds like the classic oil pressure switch, thermostat leak, which on CIS cars requires a full engine drop. It is not a big deal if you've done it before. Just be sure to disconnect all of the wires, oil lines, and linkages. Check twice, three times just to be sure before letting the engine down gently.

If you are lucky, it will be the engine oil cooler seals because you can change those with a partial engine drop, but it's so much easier with the engine out, that I would probably change those too. I'd expect you are in for an engine drop to change all of these parts. The 911SC should be completely dry underneath with no oil leaks.

Peter Zimmermann · 07-09-2008, 10:56 AM

Quote:

Originally Posted by toddu

I'm hoping I can fix whatever it is with motor in car. Dripping onto the exhaust creates some good smoke at times.Todd

The leak that you describe can also catch fire - put the car in the garage until you can fix or get it fixed! That part of the exhaust runs extremely hot, and as Rusnak stated, the leak is classic thermostat o-ring/oil pressure switch (I pull the engine to fix them, partial drop is too hard on my back).

toddu · 07-09-2008, 06:25 PM

So, sounds like I can change just the gasket on the thermostat then. Any way to check if it's working ok while I'm in there (in case I need to replace it)? I guess this all will explain my flywheel noise when the car has been sitting. I suspect oil is leaking onto it.

This sucks!! I've been starting to plan a rebuild that I won't get to for at least another 18mos. That means another drop. Good practice I guess.

Todd

rusnak · 07-09-2008, 06:29 PM

I would recommend changing the o-ring on the thermostat (green one) and the oil pressure switch both. If you want to really go for it, then change the 3 oil cooler seals while the engine is out. No tellin when you will get to the engine rebuild if it's runnin ok, so might as well fix the oil leak now. When you get to the engine drop, let me know and I'll post some pics.

toddu · 07-09-2008, 06:55 PM

my bad. I plan on replacing all suspect gaskets, but I wasn't sure if I needed to do the whole thermostat or just that gasket (along with all others). I get it now though.

this is all making sense now. I was having weird oil light symptoms (pressure fine but light on sometimes). New switch.

Appreciate the help!!

rusnak · 07-09-2008, 07:53 PM

The thermostat only bolts back in one way, so you can't re-install it incorrectly. Just clean the top of the motor really well, take the thermostat out very carefully, and when you go to reinstall the thermostat with the new o-ring on it, be sure to lubricate the o-ring very well with clean motor oil. Yep, the oil pressure switch turns on the oil light.