HELP - major oil leak .... then nothing

[MT]

Hello all - urgently need some guidance.

Got my 66 swb restoration finished, registered and went for my first trip to the petrol station to fill up (about 5 miles). On arrival there was a lot of oil smoke and about a pint or more of oil was gushing (it seemed like gushing!) down both sides of the front of the engine (near the transmission). Made a VERY large puddle under the car, then stopped. Looking at the oil trail it only started about 30 yards from the petrol station, and I had oil pressure throughout. Recovery lorry home

Anyway on further examination - lots of oil on the top of the shroud mainly at the back, little if any underneath the shroud. Top of oil cooler dry, oil dripping down the front of the engine either side of the transmission and over the front end of the valve covers. Got it home, jacked up, cleaned off - as an aside itlooks like it was over-filled, but not by more than a litre I'd guess - nipped up the valve covers ever so slightly (I know they should not be very tight) and then I ran it for 5 minutes. A few drips and a bit of smoke as oil burnt off the SSI's, but that's all. Sat all night in the garage, not a drip underneath. Engine out this morning, no further forward. Given the distribution of oil (top cover, both sides) you'd have to think the oil thermostat and/or the pressure switch but both show no further signs of leakage. I have removed both today, and the o ring is good (and new). Breather hose cover next to these is also tight and shows no evidence of gasket failure. How can you get such a major escape of oil, then nothing...... can't be a split hose, crack or gasket blown you'd think.

Now this trip was the first time the engine had been really hot since its dyno run (where Neil replaces the thermostat and pressure switch with his own so they were not tested). Seems likely that when the thermostat opened for the first time it dumped a load of oil out onto the shroud - but how???? I thought it likely the secondary section of the oil cooler, or the top two seals had gone, but there is no evidence of that - indeed the top of the oil cooler is 'rusty' if anything, and if the leak was lower down how did it get onto the top of the shroud and down the other side without getting oil all over under the shroud as well?? I know the fan can blow stuff everywhere, but that would mean EVERYWHERE!

Is there a relief valve in the thermostat? Because it looks very like a big dump of oil (from my over-filling?), then nothing. What is that little black screw thing on the top?

Current plan, unless anyone can suggest otherwise is to fit another thermostat and pressure switch (from the 2.4E engine), refit, cross fingers and go for another ride....

Perplexed of Newdigate

Mick

[Bootsy]

Could it be purely down to the overfilling? I knew somebody who had a similar experience and it was because he'd taken his oil level wrongly (cold and not running) and then filled it up a fair bit.

[barryb]

Hi

When I rebuilt my engine I put in the required 9 litres and because it was all new I thought just pop the last of the can in. Well for the first 50Km the smoke was terrible from the echangers both outside and inside the car, then for the next 100Km only round roundabouts at speed. Now 750Km later the level is right on the dip stick and no smoke and no drips.
Lesson, don't overfill unless you are lookong for an oil fire, I was lucky.

Barry

[MT]

A few pictures:

What I am completely flummoxed by is HTF it is possible for my engine to vomit about a litre of oil, clearly under pressure, in something like 15-30 seconds (max) all over the top of the back of the engine shroud and then seal up again as if nothing has happened. Oil was literally flooding off both sides of the engine when I stopped at the petrol station.

And yet, under the shroud (dry apart from a few drips through the holes in the shroud)



And on top of the oil cooler (that's the copper showing through the paint - again dry as a very dry thing)



It all points to me to the oil thermostat - the original one has some additional bits on the top that I am unsure of their purpose, so if anyone knows please do tell. Is it some form of relief valve? I have taken the one from the 2.4E engine and plan to fit it instead tomorrow when the engine goes back in. You can see the difference in the photo. Note: I have already swapped the o rings ready to fit tomorrow so the lower one had the new green seal when the leak occurred - it is new and looks it)



Now the later version also has larger ports in and out, and the 'O' ring groove is slightly higher The PET shows the earlier version used to 71 (901.107.751.00) and then 930.107.765.00. Are they interchangeable??

Can't see how it could be anything else. Oil pressure switch was tight, looks fine and shows no sign of any leaking. Breather hose gasket looks fine as well and I cannot see how they could vent so much oil so quickly and show no visible sign of damage.

It's a b*gger, it is.

Never mind took the opportunity to fit the proper PMO manifolds while the engine was out...



Let's hope they don't get a 20w 50 'douche' as well...

Mick

[Bruce M]

If the oil was overfilled, it has to find an exit route from the tank. Could that be the breather system and therefore the oil ended up leaking from the air filter housing?

Have a look at this it might be useful (maybe )

http://forums.pelicanparts.com/porsche- ... 2-2-a.html

[squirdan]

unless you have a catch tank fitted thats exactly what happens..it come pissing out of the air filter housing all over the top of the engine !

[MT]

First prize to Bruce M, with runner up prize to Dan


Mystery resolved …… somewhat to my embarrassment! I have resisted the temptation to just keep quiet for the benefit of others.

Cause was a combination of two things.

1. I had over-filled the oil tank by at least a litre, possibly 2 as I was not aware you had to measure with the engine warm and idling
2. I had routed the breather pipes wrongly. I had joined the crankcase breather to the 'T' next to the filler cap, and the other from the upper tank nozzle to the air cleaners

There was oil all over the inside of the pipe to the air cleaners, and because they are just 'rain caps' that house the K&N filters that came with the PMO's with a nozzle in the side, the oil drops straight out of the holes and onto the shroud. As the revs increased, and the 'blow-by' accordingly, it pushed vapour into the tank lower down than intended, and probably below the oil level, this puked the excess out of the upper nozzle on the tank and along to the air filters …… and out onto the shroud.

Have cleaned, refitted the engine with the original oil thermostat (you cannot use the later version as the body is 3mm longer I found from a patient chap on Pelican) and routed the hoses correctly. Filled with oil carefully, and been for a couple of 10 mile runs. Apart from quite a bit of oil smoke on occasions from the screen vents as there is still probably some oil in the SSI's, no further leaks or drips underneath.

Numpty of Newdigate

[ross.mcw]

Good news - glad to hear it was nothing serious Mick!