Help With Oil Leak Please

[Alan Lindquist]

1980 911 SC. I had an oil leak at the top back of the motor according to the pool of oil on the top of the back of the motor. I pulled the motor and replaced the oil pressure switch, the breather box gasket, and the oil thermostat gasket.

I don't know of another possibility for oil on the top back of the motor. Did I miss something?

I re-installed the motor and the leak was worse. I pulled the motor again and went after the same three spots with permatex and re-installed the motor. I have the same problem.

Can I have some ideas on what you think is going on? How could a leak go from bad to worse?

I also replaced the three seals on the oil cooler on the first pass, and inspected it on te second pass and can't see any indication that oil is coming from the area of the cooler.

Ideas?

I don't mind pulling the motor again, but I need a more certain approach for the next effort.

[DRACO A5OG]

Before you drop the engine again, wash the area and let it dry out. Drive her and see where the oil could be coming from with a mirror

Check the Breather Hose connection to the Breather, Mine was loose and it sprayed a puddle back there.

Also the Oil Light Switch, if you opened her up to re-torque, the washer would be shot, it is a crush washer and can not be reused.

[afterburn 549]

Like said..and some talkum (baby powder) powder dusted on it may help if it real elusive

[NOLAsc]

Originally Posted by DRACO A5OG

Before you drop the engine again, wash the area and let it dry out.

This will be a stupid question, but what's the best way to clean up in there?

I'm in kind of the same boat as Alan. Only difference is I'm pretty sure it's my breather hose and/or gasket. I did not replace them last time I had the engine out. Didn't want to loosen any CIS components to get the cover off for fear of messing up something else. I did replace the thermostat o-ring and the pressure switch.

Thanks,
Shawn

[wildcat077]

Shawn,

I used a can of brake cleaner ,some paper towels and an air hose to clean up my mess back there ...
Then of course,you are blowing all the **** down on the lower part of the engine but you should get some Simple Green and a pressure washer and give the engine a thorough cleaning afterwards.
Turns out my $6.00 oil light switch was cracked and my crankcase breather hose was split right at the clamp.I cut four inches off it and re- clamped it back on,no more leaks !

Got black flagged on my last session in June at the track because i was leaving a James Bond type smokescreen ... lol
To do it properly you will need to remove your air box completely and the AFM as well for proper access !

Cheers !
Phil

[NOLAsc]

Thanks Phil.

[afterburn 549]

You might as well have the O.P switch in hand B you start...a tip a light coat of JB weld around the plastic to metal part on top (to stop it from doing it all again) it works..! dont try this a on a used one as there will be oil in it the JB will not stick

[DRACO A5OG]

Nola, not for nothing but try Electric Component Cleaner, it is less harsh on rubber/plastic components in that area and drys quickly too. I used half a can to clean off that area. Put a pan under the front part of the engine to catch the fluid and debris :EEK: if you have painted garage floor like mine it will stain/melt it.

Drive her around till hot and then check with the mirror, you should see where it is weeping.

+1 powder would be a faster idea but will leave a mess, but GUNK and water should take care of that.

Jim

[Alan Lindquist]

Thanks for the replies.

My breather box hose seems shot, but I didn't imagine that it handles so much oil flow. I guessed that it was handling crank case pressure. It really handles oil flow?

[steely]

It's not supposed to handle flow, it's supposed to vent, but sometimes oil can get in there.
Sometimes, a PO may have put too much oil in the crank, and some will blow by - if some residual oil is in the line, that could be a source. True story, I removed the entire intake to update the gaskets etc, and found pools of the stuff in the breather lines and blower (cylindrical portion of the intake).

[steely]

don't know how to edit a pic into my previous post - here's a pic of some earl I found everywhere. Probably from a one time event. Do like Jim and others have said, clean and dry until you locate.

[Alan Lindquist]

Thanks again for all the advice.

It seems to have been the crank case breather hose. It was hard and brittle and cracked. I should have paid more attention to it when putting the gasket on the breather cover. I replaced the hose and I'm not leaking on top any more. Now I need to get after the timing chain covers. My car will transform from a leaker to a spot dropper. I can live with that. The motor has over 220,000 miles on it, so I'm just nursing it along to it's eventual replacement.

BTW - Instead of dropping the motor my friend and I cut an access port in the rear firewall and worked it from the backside. He's welding up a flange so that we can bolt it back on.

[DRACO A5OG]

Access panel? NICE please post pics.

[slodave]

Alan, my engine has over 238,000.... I went from a serious leaker to spot dropper. It can be done. Good luck!