Oh the Joy, 3.2 Case Through Nut LEAK?
 

So I was under the car today and noticed a new drip trail emanating from the nut circled in red D-Side on the engine case. I assume it is a case through nut. Is there an oring behind it that may be leaking?

http://img.photobucket.com/albums/v5...psfbvwqiq2.jpg
Not my car, thank goodness :eek: but thanks donor from Rennlist :D

I checked the torque, it is at 25 ft lbs so I am thinking an oring that gave out.

http://www.pelicanparts.com/catalog/...00640-M213.jpg
1985 Porsche 911 Carrera Targa - Main Engine Components - Page 3

TIA,

Jim SmileWavy

Yes, that is a case through bolt which helps clamp the intermediate shaft.

The common problem with these, is that the stud pulls out of the other side of the case which makes it impossible to torque. But if yours is at 25lb ft, then that is unlikely the issue. Lucky too, since the only way to fix that, is split the case.

There is no o-ring.. just a washer and nut. Try cleaning the thread, spread some thread sealing compound, then put the nut back on and re torque.

technically , its not a case through bolt. just a stud and nut.. the case through bolts are around the cylinders, use o rings and have pressurized oil flowing around them. just like mikeD said, remove nut, clean it up and install new nut and washer. there I no pressurized oil behind that nut.

Oh Perfect, thank you Brothers!

I've seen a video where the guy recommends to put 574 under the washer of this nut.


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i would use black silicone rather than 574 there.

I'll try some 3Bond aka HondaBond/YamahaBond on next oil change.

sorry to hijack but i have a question. i have the same issue with the lower dome nut behind the oil cooler. i tried to torque it and right when i got to 25 lbs i felt it pop, meaning it jumped threads inside, which would explain why that nut was loose in the first place. any suggestions?

I sealed it and it worked, no more drips.

Every once in a while the Porsche Gods smile on you. :)

"sorry to hijack but i have a question. i have the same issue with the lower dome nut behind the oil cooler. i tried to torque it and right when i got to 25 lbs i felt it pop, meaning it jumped threads inside, which would explain why that nut was loose in the first place. any suggestions? "

Not good. Magnesium case?

[QUOTE=boosted79;9387050]"sorry to hijack but i have a question. i have the same issue with the lower dome nut behind the oil cooler. i tried to torque it and right when i got to 25 lbs i felt it pop, meaning it jumped threads inside, which would explain why that nut was loose in the first place. any suggestions? "

Not good. Magnesium case?[/QUOT
you could install a heilcoil and reset the stud. If the case is apart then I would use a timesert instead.

case is not apart and trying to keep it that way. i put a double nut on the stud and turned it till it bottomed out. now just waiting for the oring to arrive from our host to try again. i tried to double nut it again to turn the stud out to remove it but it did not want to spin. so hopefully it will stay. i don't think it will be possible to put a heli coil in there without splitting the case, unless it fits through the hole which is slightly larger than the stud anyway. i'll see what happens first before i go that route.

Yeah thats why i was thinking a helicoil might fit, a time sert will not because it has a shoulder on it.

One a mag case, when that stud pulls and leaks oil, run a 10x1.25 tap in the hole and use a short bolt and aluminum washer. No drilling needed, no damage done. Timesert the stud hole sometime when the case is apart.

Make it work
 

Like he said!

Thanks for sharing your skills
For All these years.
Makes it possible for us do it yourselfers.;)

Alan

This is a great suggestion. Thanks
Do i torque it to 25 ft lbs like the original nut on the stud?

25lbs is probably why it pulled. 18 max for an 8mm fastener. The 10mm Bolt trick just needs to be lightly torqued so it seals. It's not holding anything.

Too bad that isn't going to work for Drola's problem-great idea for Dracos though!

why would this not work for me?

Sorry but
 

Because the fix is useful for a stripped 8MM stud-the one you've described
is a 10MM already.

ah i see
well, for now i think i'll just put a new o-ring with some rtv sealant and hope for the best. since i bottomed out the stud i can tighten it pretty tight and it does hold. i just know not to try to put 25 lbs to it like last time (as per the bentley manual).
my concern was that it may hold one of the main bearing in place or something along those lines. but if all it does it seal the case i think i should be ok.

drola - that cap nut goes onto a case through bolt, only in this case, and for the one above it, it is not a through bolt, but a stud. But it has the same job - to hold the case halves together around a bearing. In this case it is the large #1 crank bearing - the one with thrust surfaces.

I'd torque it to the spec for these M10 fasteners, which is 35 Nm, or 26 pounds/feet.

There is a way of dealing with the head studs in these engines: If it holds torque, stop worrying about it. When one no longer holds torque during a periodic check (say when setting valve clearance), time to take the engine apart.

I'd apply the same logic to this case 10mm stud.

Here is a picture of a case apart, showing the left side case half. I've not heard of these pulling the way head studs do on these mag cases, but John or Bruce may well have encountered this since they go through so many engines.

http://forums.pelicanparts.com/uploa...1481861765.jpg