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3forall
Joined: 29 May 2015 Posts: 17 Location: Canada
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Posted: Fri May 29, 2015 10:06 pm Post subject: Leaking turbo oil inlet |
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The gasket between the oil inlet flange and the turbo is leaking quite badly and sending oil onto all the hot parts downwind from there making one heck of a smoke show. Although I like that it has taken care of tailgaters, I really should get it fixed.
The question is how to get to the gasket. The whole area is quite tight. As it is I see two potential ways. Either remove the charge tube and try to manage in the now slightly less tight space. The other way would be to remove the turbo.
Any opinions/suggestions would be welcome. _________________ 1981 924 Weissach edition
1982 931 - Megasquirt and liquid intercooler
1969 911 |
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Fasteddie313
Joined: 29 Sep 2013 Posts: 2596 Location: MI
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Posted: Sat May 30, 2015 3:24 am Post subject: |
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If its a leak where the hard line connects to the mount you can snug it up, I think I cut a 19mm open end short for this.. (check size before you cut)
If its a leak between the mount and the turbo you can try tightening the 2 allen nuts with a bunch of extension, universal, and an allen driver. If you dont have an allen driver you could cut about an inch off of the correct size allen wrench and use it between a socket and the nut..
If that doesn't make it stop leaking and the leak is between the mount and the turbo it may be possible to unbolt the mount from the block, take off the hardline, remove the 2 allen nuts, and shimmy the mount up enough to get a new seal in there, or maybe you can even get it completely out, but I don't know if its possible without completely removing the turbo.. _________________ 80 Turbo - Slightly Modified |
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3forall
Joined: 29 May 2015 Posts: 17 Location: Canada
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Posted: Sat May 30, 2015 1:07 pm Post subject: |
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Fasteddie313 wrote: | If its a leak where the hard line connects to the mount you can snug it up, I think I cut a 19mm open end short for this.. (check size before you cut)
If its a leak between the mount and the turbo you can try tightening the 2 allen nuts with a bunch of extension, universal, and an allen driver. If you dont have an allen driver you could cut about an inch off of the correct size allen wrench and use it between a socket and the nut..
If that doesn't make it stop leaking and the leak is between the mount and the turbo it may be possible to unbolt the mount from the block, take off the hardline, remove the 2 allen nuts, and shimmy the mount up enough to get a new seal in there, or maybe you can even get it completely out, but I don't know if its possible without completely removing the turbo.. |
The leak is between the inlet flange and the turbo, not where the oil line connects. I did try to tighten it but only one of the two allen bolts are accessible. The one that I managed to get to wasn't going to get any tighter. Getting to the other one is my main objective since I would rather not have to take off the turbo. I guess pictures would explain the best, I just need to figure out how to post them on this site. _________________ 1981 924 Weissach edition
1982 931 - Megasquirt and liquid intercooler
1969 911 |
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ideola
Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI
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Posted: Sat Jun 06, 2015 12:35 am Post subject: |
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There is a round profile green rubber o-ring that fits into a groove on the underside of the turbo mounting bracket, and seals against the upper mounting surface of the bearing housing. What usually happens is that the o-ring loses its elasticity, gets compressed, takes on a square profile, which results in the oil leak you describe. No amount of tightening will fix this, the o-ring must be replaced. I believe the OEM part is still available, but it's been quite some time since I last checked.
There is also a copper crush washer for the upper oil feed line. These will leak too, so I wouldn't assume that it's not coming from there.
The drain line also has a larger brown o-ring that suffers from the same failure mode as described above. The OEM version of these are NLA, but you can get the specs out of PET and order a suitable replacement from McMaster Carr.
While you're at it, you should replace the four alu crush washers for the oil cooler lines, and the large alu crush washer for the main banjo bolt that secures the oil filter console to the block. These are quite troublesome to seal, although I've had some success by coating the crush washers with blue loctite and tightening to OEM specs (H/T to Rasta Monsta). I can't recall whether these are still available as OEM parts, but I believe the specs are listed in PET, so you should be able to find suitable replacements inexpensively, again from McMaster Carr. _________________ erstwhile owner of just about every 924 variant ever made |
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GeneT95
Joined: 07 Nov 2019 Posts: 12 Location: Chesapeake, Virginia
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Posted: Wed Dec 04, 2019 8:21 am Post subject: |
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I'm just bumping this to say thanks to everyone who contributes. Really. I've had a 931 for about 5 months. It's a great running car with a fresh rebuilt engine/turbo/wastegate etc, but I've had to do a couple things (new water pump, cracked ignition switch, chase small turbo oil leak) and having some place to hunt for answers not contained in the manuals is beyond fantastic.
My small oil leak at the turbo inlet was likely due to a loose rear allen bolt. Using 2 locking extensions and a swivel adapter, I taped a allen socket to the swivel (so it wouldn't be left behind) and found the hard to reach allen had 1/2 - 3/4 turn until it was even snug before tightening. Here's to hoping that was the problem. |
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924RACR
Joined: 29 Jul 2001 Posts: 8794 Location: Royal Oak, MI, USA
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Posted: Wed Dec 04, 2019 10:38 pm Post subject: |
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Hope it works for you; to date, every time I've removed the turbo I've found that o-ring (that Dan referenced in his post) to be cooked hard as a rock, no pliability to seal, and needing replacement.
No doubt the heat from the turbo kills it.
I do wonder if Porsche under-specced the original part with respect to temp, and if perhaps the newer green ones hold up better thanks to modern materials science and engineering...
Certainly haven't had any leaks after replacing those, but it's taken turbo removal to make it happen. _________________ Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype |
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GeneT95
Joined: 07 Nov 2019 Posts: 12 Location: Chesapeake, Virginia
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Posted: Thu Dec 05, 2019 9:48 am Post subject: |
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Yeah. I'm hoping not. The turbo is newly rebuilt (not by me) in the last 2000 miles. I wouldn't expect a hard o ring but a poorly seated one or something else.
Can the orings of that section be replaced without taking the whole things out? Or can I unbolt just the upper portion and reseat if I need to??
I'm at work, so I don't have a manual with me (shame) so the question may indicate my newness. _________________ 61 Biscayne : 62 Bug : 81 931 : 88 944 NA |
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Carrera RSR
Joined: 08 Jan 2010 Posts: 2309 Location: Somerset, UK
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Posted: Thu Dec 05, 2019 6:33 pm Post subject: |
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Need to drop the turbo to replace the top O ring and all the extra parts to remove do so. Its a painful process. This may mean new gaskets for manifold to turbo and turbo to exhaust unions. Same potentially with waste gate and J pipes. In addition its probably wise to replace all fixings if they are looking crusty.
So to replace a leaky 50cent O ring, it will potentially cost 1-2days labour and several hundred bucks of consumables if you do the job right.......hence PO maintenance may me lacking on a cheap craigslist turbo...
When reinstalling the turbo I use a smear of Loctite very high temp exhaust sealant on all gas and oil joints to try to help the seal. So far so good.....
PS just had an issue with oil pee'ing all over the turbo area. I thought it was the oil joints or turbo. On closer inspection the straight 15mm oil breather hose joining the head breather hard pipe to the oil drain hard line had loosened. I probably failed to tighten early this year when installing new turbo. This was the cause of the oil and thankfully an easy fix and clean up.
You can see the hose above the turbo in this pic
Untitled by stevenmcooper, on Flickr _________________ 1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252 |
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