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[jamie]

Also thanks Neil, Keith, Jason.

Neil - that link is helpful. I found another on that forum that might be even more relevant to my issue, but I need to dig a bit further here first...

[jamie]

Just got back from holiday. Nice to spend some time away from the car, but once I was home I was straight back in the garage.

I checked the flywheel area for leaks again, hoping that a bit of fresh perspective might help. Nothing jumped out at me. The oil galley plug seemed a bit loose, so I removed it, cleaned the threads and the threads on the case, and reassembled it, tight, with Marston jointing compound.

Whilst I was away, I mail-ordered a new (single lip, Viton) oil seal, so I put that in. I didn't see anything wrong with the old one, or the way it was seated, but what the hell.

I also checked the oil level. With the engine on level ground, it's exactly at the top marker of the dipstick. Bearing in mind that 1/4 litre of oil has leaked out of the engine, and that the car is also tilted forward a bit (front wheels on the floor, rear of the car raised on axle stands), I wonder if it could have been too much oil which was causing the leak?

In other news, I also noticed that the spark plugs were not tightened in cylinders 1 and 3. Can't blame anyone but myself for this - I must have just forgotten to check. I tightened them up and could really feel the difference in compression when rotating the flywheel. Derp derp.

[jb]

When I had a 356 I seem to remember taking the engine out a number of successive times with a similar oil leak.
I have only vague memories of the problem but I think it was something to do with some dowels in the flywheel having elongated which now seems like nonsense to fob me off but I thought I would mention it.
My main memory is taking the engine out with a scissor jack and skateboard and putting it in my mini cooper where the front seat should be to take it down to the engine expert.

[jamie]

I don't have a Mini Cooper, so it looks like I'm plain f*cked.

[jjeffries]

Jamie, any update? Hoping that all is well. John in CT.

[mycar]

Jb's comments about dowel pins and flywheels rang a bell. Here's a recent thread from the Registry that may be of help.

http://forum.porsche356registry.org/vie ... =1&t=40492&

[jamie]

Thanks for the link Mike. My leak definitely isn't at the dowel pins - the clutch plate stays dry. It's the seal.

So, a recap...

On Christmas day I ran the engine for the first time and discovered oil was dripping from the clutch bellhousing.

The day after boxing day, I removed the engine, replaced the main seal, reinstalled the engine and ran it again. The leak was still there.

Then I went on holiday for two weeks. Then I came back for two days, managed to ignore the car, and then went away on work for a month.

I got back yesterday. Today decided that I would take another look with a fresh set of eyes. I found the oil level was very high on the dipstick and concluded that this was the problem. The front of the car is on its wheels, and the back is high up on axle stands to facilitate sliding the engine in and out from underneath. So I removed a bit of oil from the engine, lowered the car so that it was level, reinstalled the engine and ran it again.

It didn't work - the cocksucker still leaks. There are actually now two - the same big one at the crank, and a minor week at the oil pump cover (which looks like an easy fix). I'm pretty certain the one at the crank is the main seal, but I can't understand why. It looks to be seated right, no kinks or other weirdness.

Anyway, I'm at a very low ebb on the enthusiasm front, so my plan now is to take it to a shop and get it bench-tested by someone that knows what they're looking at.

[jjeffries]

That's a be-atch. Good idea to take it to a good engine man (or woman...equal opportunity commenter here). Someone with the finest micrometers to get a complete picture of how the crankshaft end is playing with the rear main seal, look for scoring, etc. I hope the fix comes in soon. John.

[sladey]

Good call Jamie. You'll get it sorted

[KS]

Are you sure the case isn't cracked behind the flywheel? On a VW engine, such cracks are not unknown - they remain virtually undetectable until the engine runs and gets warm, then open up to leak like the Torrey Canyon, before (visually) closing once cool. Just a Monday morning thought.

[jamie]

Thanks guys.

Keith - Good call. It didn't leak before it was rebuilt, but I'm not certain of anything anymore.

The other thing that crossed my mind is that there's a high oil pressure situation occurring somewhere in the system, that is being forced-out at the seal...

[Cortina]

Thanks guys.

Keith - Good call. It didn't leak before it was rebuilt, but I'm not certain of anything anymore.

The other thing that crossed my mind is that there's a high oil pressure situation occurring somewhere in the system, that is being forced-out at the seal...

That was my random thought last night when I saw the "new leak" at the pump face. Link up a "known" accurate pressure gauge at the nearest available tapping point and put a figure on it ! ?
Like all things , it is fixable ....... but first you got to find what to fix .

cheers
Alan

[911hillclimber]

It didn't leak before the rebuild then, so something has changed during the re-build obviously in that area.

The seal should not be under pressure just splash from the oil splatting around in the sump.
If there IS pressure in the case then oil will be forced out while running.

I would be looking for a leak-down test to be done by the person you take it to first, then you can see if the case pressurises.

If the breathers are open then they will allow a reasonable pressure to pass, if blocked, non-existent then you will get oil passing (through the system's least line of resistance) very quickly.

I think we have been here before with this issue, but thought it worth raising again.

Keep going Jamie; pita but soon will be sorted.

Just try a race car if you want frustration....

[Nige]

Are you sure the oil leak isn't at the top of the engine somewhere and dribbling down making it look like the leak is from the end seal?. I'm unfamilar with the layout but is there a pressure switch or something towards the back or leaking from the oil cooler or something?

I am guessing.

[Nige]

Ignore that, just looked back through your posts and it's pretty obvs it's the crank end.