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bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

Parked the car and let it idle a bit to cool down, and noticed there was a pretty significant oil slick under the turbo. Cleaned it up best I could and then started the car....reasonably certain it's leaking from the oil feed where it connects to the bearing housing. Actually not sure which side of the mount. Either way, as I understand it, the turbo has to come out. (*sigh*).

A couple weird observations. First...I'm either missing one of the studs on the turbo that the oil feed line is held on with, or it broke off where I can't see it, because I just have a hole there. I can't say if that's a new development or if it's been like that for a while. If it's new, and it just came out somehow, maybe replacing it will fix the problem? I'm not that lucky, so probably not, but I will try if I can find a stud and get it threaded in there.

The other weird thing is that my car starts up, idles pretty good for a few seconds and then gets low and surges and sounds like it's going to die. It doesn't, usually, but it's very rough. I can open the throttle and rev it though...but it seems like a vacuum leak or something. It was NOT doing this until after I found the oil leak, so they have to be connected somehow, right? I don't see how, but it seems like too big of a coincidence.
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1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)

kondzi · Joined: 02 Jul 2018 Posts: 485 Location: Poland/EU

There is a rubber elbow that is almost always to be replaced. It's connected to a metal hose just above/behind the pulley and goes from underneath to the intake manifold IIRC. Maybe that's the culprit?

Regarding the studs - share a photo what are you missing

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Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

So you know the oil feed line that attaches at the top of the turbo bearing housing (I think it actually goes through the mount that attaches the turbo to the block). That attachment (the oil feed line) is via two studs in the turbo bearing housing. One of them is either broken or missing. Coincidentally (or not) the oil appears to be leaking from that connection. I haven't been able to get a decent picture of the area yet.

924RACR · Posted: Tue Jan 31, 2023 10:28 pm Post subject:

Not fun, but achievable with the motor installed - have done this a few times.

Yes, the oil feed line goes through the cast iron mount; strictly speaking, the oil feed line goes into a compression fitting on the top side of the mount, which then seals to the top surface of the mount with a copper washer. If you have a leak on the top side of the mount, these are the two points it can fail at. The compression fitting is extremely hard to tighten while installed thanks to 17mm hex size and very little clearance to swing such a large wrench.

The studs support the weight of the turbo, in part, and clamp it to the bottom side of the cast iron mount, which is sealed with an o-ring. This will leak without both studs and nuts in place, and the o-ring is usually hard as a rock thanks to the temps.

So you'll want to have the necessary exhaust gaskets (turbo to manifold and turbo to downpipe), plus the sealing rings associated with the oil feed. The drain can be disconnected at the compression fitting, the drain elbow wouldn't necessarily need to be removed from the turbo to R+R.

However I would suggest you consider having the turbo rebuilt, maybe even upgraded, while it's out...

Also "while you're in there" would be the really hard to get to hose elbows etc, like the one mentioned on the bypass valve...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

kondzi · Joined: 02 Jul 2018 Posts: 485 Location: Poland/EU

I have currently my turbo out with engine in place. It was challenging to remove. Hope I will install it properly.

I’ll take some photos in the afternoon and post for reference.

EDIT: Here we go...

The rubber elbow I was mentioning connects to the recirculating valve.
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Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)

Mike9311 · Joined: 14 Dec 2004 Posts: 1678 Location: Chicago-ish

I had a leak like this on my 80. Turned out it was the oil line itself. It had a crack
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1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

madislandguy · Posted: Thu Feb 02, 2023 11:09 am Post subject:

I had a cracked oil feed line on an Xr4ti and misted some oil on the exhaust manifold. Burned up everything on the passenger side of the engine compartment, ruined the hood and even cracked my windshield. Turbo oil leaks are not to be trifled with..

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

Kondzi,

For some reason I can't see your images, they are just "broken image" icons or whatever that's called.

FWIW, I had the head off last year, and replaced the wastegate as well. So the turbo-to-manifold and turbo-to-downpipe connections should not cause me any major problems. Too bad this didn't happen at the same time, I'm sure it would be much easier with the head and exhaust manifold out of the way.

Can anyone give me a basic step-by-step, so I don't head off down the wrong path? Since this is coming out from the bottom, what else do I need to remove first, other than exhaust stuff?

Also...does anyone know the size of the studs that the oil feed attaches to? The ones in the bearing housing of the turbo. Since I'm missing one, first thing I want to try is getting one in there if possible.
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)

kondzi · Joined: 02 Jul 2018 Posts: 485 Location: Poland/EU

Try right click and open in new window. Not sure why for some my photos wont appear linked to the forum…

I removed my turbo with engine in place.
Started with the intake part that goes into the aluminum connector between turbo and intake, then the connector.
Removed the bottom parts from the KJet housing / distributor.
In general everything that was en route. I had to loosen the sway bar - finally I removed it. Then the lines and bolts / studs on the turbo „stand” that bolts to the block (it’s in my photos). It required to replce your wrists and fingers with rubber ones though

Anyway I did not remove / loosen the exhaust manifold.
IIRC most of the bolts / studs are 13mm, some 17mm and maybe a 15mm, maybe.
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Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)

924RACR · Posted: Thu Feb 02, 2023 10:30 pm Post subject:

I can see the pics just fine...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

Thanks for the info, that's helpful.

I don't know what's up with me and the pics. I'm just using Chrome or Edge in Windows. Weird...
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11724 Location: PacNW

If there's any reason at all to remove the motor for this operation, you'll save time in the long run. Like, if you need a clutch, or to reseal oil leaks, etc.

It can be false economy to use work arounds when better quality work is attainable on an engine stand.

Years of fighting these cars has taught me not to fight.
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

While that's true, I have no room or tools to remove the engine. If I need to do that, it means I need to pay someone else to do it, which I really do not want to do.

Mclaren924 · Joined: 13 Oct 2021 Posts: 171 Location: California

Beartooth · Joined: 05 Apr 2022 Posts: 212 Location: Roberts, MT

I removed mine and have it back in now; if you scroll down, you'll see the thread on that. It is a pain, and I've never had the motor out on mine, but I could see where it might not be any more work if you have the right equipment. I removed the sway bar, and took the steering rack loose, but not completely out. One of the bolts for the turbine flange is a real pain to get to (an impact grade swivel adapter seemed to be the best thing there), as are the oil feed lines (I used a crow's foot there), and the wastegate bolts. If you've lived a clean life and everything comes apart without any broken hardware, it's just a lot of fiddly stuff. Of course, one of the turbine flange bolts broke off in the manifold... The one thing I needed help on was getting the turbo back in place and the bolts started. Maybe there's a better way of going about it, but I could not find a good way of holding it in place and getting a bolt threaded in. I still need to finish torquing everything down, and I'm going to take the wastegate pipe off and put a flex joint in it (I can see it cracked and was repaired at one point). Unfortunately, my snowmobile (mountain machine: a Polaris 800 Pro-RMK) blew a piston the first ride out this year, so that's taken me away from the 931.
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1980 931 diamond in the rough