Oil leak after seal refresh

[bugstrider]

Hello fellow Pelicanites,



I just the 78 911 SC back on the road after an extensive seal refresh. The triangle of death, oil cooler, return tubes, intake/exhaust cover, rocker-arm gaskets, and rear main. Removed, cleaned, Mideast blasted and painted the exhaust/heat exchangers with VHT. Fresh oil 20-50 Castrol with a new filter. The engine was also cleaned of the 35 years of grime that has accumulated over 3 decades. Drove the car home approximately 50 miles parked and immediately noticed the smell of oil being cooked on the exhaust and looked under the car and observed multiple drops of oil on the ground literally minutes after backing in. Even saw several drops on the ground from the drive in. In looking under the car, I notice oil on the case seam and a drop on the cross member connecting both exchangers. Yes, I know this is typical of these older cars and being 35 years and with 259k on the clock and not knowing if the engine has been apart, am I expecting too much thinking the seal refresh should have resolved the oil loss or at least slowed it down? I was just surprised to see the multiple drips after a 50 mile drive. It was my hopeful attempt that the refresh would slow the leaks down so I could possibly get another year out of the engine baring a catastrophic failure before an overhaul.



I'll post some pictures as soon as I can link them up with the post.



Thanks Trevor

[Bill Douglas]

Other than the oil leaks it's nice and clean How is the car going?

[bugstrider]

Thanks Bill,

Car drives great other than the leaks. Runs at 2800 rpm at 70 indicated on the speedo and feels smoother than the pre seal work. It's nice to get it back on the road. Although got a whopper of a surprise when I discovered a peddle cluster full of brake fluid. I guess it was a result of a brake flush gone crazy. Levels on the MC are at maximum with no change in level. Needless to say the peddle cluster and floor pan have never been so clean.....

Anyway, just trying to keeper fresh and tidy. My dad instilled upon us youngins, a clean engine is a happy one....

Cheers

[Cooper911SC]

Nice work on the re-seal. Exhaust and bottom side look clean.

I'll be doing the same on mine soon.

Gearbox 1st gear synchro gave it up for a second time in 312k on Friday evening.

My oil leaks look the same. Biggest offender is the pulley side case O ring. Oil runs across the rear hard line plus down the case rib. Annoying, but that's the only real leak.

Gonna' wait it out until something really breaks before doing the engine. :-)

Happy motoring.

Cooper

[tobluforu]

What oil are you running?

[fanaudical]

Any possibility the rear main seal went in wrong? You may have seepage there that is running down the case line.

[bugstrider]

Originally Posted by tobluforu

What oil are you running?

Castrol 20-50 regular dino oil

[bugstrider]

Originally Posted by fanaudical

Any possibility the rear main seal went in wrong? You may have seepage there that is running down the case line.

I guess that is a possibility but I sure hope not since that was also replaced. I need to get it up on ramps and look around some more with a mirror and light. Man, between this and the flooded peddle cluster with brake fluid, was a buzz kill.

[bugstrider]

Ok, here is a twist in the oil leak saga/drama. Well, let's just say oil or brake fluid.....

On a earlier thread I kinda ranted a little about our peddle cluster being full of what resembled brake fluid as well as a soaking floorboard area and soggy carpets and mats. With no noticeable fluid loss in the MC. I figured it was a brake flush gone bad.

Drama warning!
In doing some general cleaning I decided to pull the shift coupler cover plate off of the center tunnel. When I did this and discovered the little surprise of even more brake fluid pooled up under the coupler, you could say I went straight to redline. Someone please explain as to what could have gone so horribly wrong with a standard brake flush that would fill every single fluid collecting low area in the tunnel with standing brake fluid. Nothing like baptism by fire in Porsche interior disassembly. Needless to say, rather than go on our first trip in the car after it sat for months at a shop, I ended up gutting the entire interior to spend all day cleaning and scrubbing and cleaning some more. Not exactly the way I wanted to spend one of my few days off. Instead, the wife and I had plans for a day spent together on a scenic drive in the Targa.







It's days like this that make you realize all you can do is laugh. So now, I don't even know if I'm looking at engine oil or brake fluid spewed all over a clean engine

Cheers Everyone

[Emery G.]

could be a shift shaft seal. i have seen those pop and fill the tunnel with gear oil!

[bugstrider]

Emery

That's a good point. Would a 50 mile drive throw enough gear oil to work its way back to the cluster? When I pulled the shift rod( none techi term) to swap out the shifter cup bushing and rod guid bushing I didn't notice any residual jiz in the rubber boots where the shift coupler hooks up. I'll need to squirrel under the trans for further investigation.


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[mnez]

2 different sources maybe? Brake fluid up front, trans oil at the back?

[bugstrider]

Found this under the front.....

Any ideas???









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[kodioneill]

I just resealed a friends 77 911 and it leaked oil down the rear of the engine and it looked like the rear main was leaking pulled the motor and found the sealing ring on the oil light switch (new) was oblong-ed causing a similar leak like yours.

[CountD]

Originally Posted by kodioneill

I just resealed a friends 77 911 and it leaked oil down the rear of the engine and it looked like the rear main was leaking pulled the motor and found the sealing ring on the oil light switch (new) was oblong-ed causing a similar leak like yours.

It really doesn't take much to do the above. You really need to forget the 'feel' you've acquired turning bolts this size with a steel washer - I think to really tighten these correctly you need to watch the base or do it by hand until it touches then maybe a half turn after that. This is what I have done almost all the time with several Italian and German motorcycles I have owned which have light alloy cases. It amazes me how many people have a heard time with this oil switch. You need to pay attention.

[bugstrider]

Update time,



So, here we are, four days into my leaking drama bag. There is nothing like baptism by fire with regards to Porsche interior removal and installation. Interior was removed cleaned and reinstalled. Even swapped out the Recaro LX-C's for factory leather. Have done two long drives and everything that was soaked by brake fluid is remaining clean. Engine drips are down to two drops. Still cannot figure out a logical explanation as to why there was so much fluid since everything is still dry.

[ManniB]

Originally Posted by bugstrider

Found this under the front.....

Any ideas???

That plug looks like the one that covers a hole in the front of the brake booster support. I don't have a picture at hand.

- Manfred

[Porboynz]

There is no mistaking the smell of gearbox oil, the viscosity is different to brake fluid as well. Assuming it is brake fluid maybe it is from fitting new brake pads, pistons all retracted into the callipers, displaced fluid overflows from master cylinder, ends up in tunnel? That plug looks like a normal plastic plug used all over a 911 to plug various access holes.

[christiandk]

Is the shift rod and rubber piece wet from gear oil?

[gamin]

Porboynz I think has it right. Overfill of brake reservoir during flush. Overfill drain line not routed properly?