tt9714

I’m in the process of removing my one-piece crossover pipe in preparation for a bottom end reseal on an ’86 951. So far I have been able to remove 9 of the 13 fasteners that attach the unit to the turbo, wastegate, and exhaust headers.

I’m looking for tips/suggestions on getting those last 3 fasteners out. Specifically:

Crossover pipe to turbo: 3 of 4 successfully removed; cannot get enough leverage on back side (bolt head) of lower right fastener (looking at turbo, closest to engine). Tried using a 15mm regular socket with 3/8” breaker bar. I noticed that the nut on this fastener is spot-welded to the crossover pipe flange. Was this a factory spec? I’m guessing that the PO tacked the nut on to facilitate reinstallation

Crossover pipe to exhaust headers: 3 of 6 successfully removed; broke all 3 loose, but now cannot get a wrench on the back side (bolt head) to keep it from spinning while turning the nut. I tried to access this flange from above without success. What’s the trick here? One idea that came to mind was applying some Loctite to the bolt head side to “freeze” it in place enough to get the nut off.

So far this has definitely been the most difficult part of the job. It’s frustrating because it’s not ~technically~ challenging, just extremely inconvenient.

951Tom

That one nut came spot-welded from the factory. I think I got the bolt off from below when I did mine. Sorry, not much help.

Tom
'87 951
'86 Supra

keith

try getting in there with a stubby wrench, also a universal may help, but I never use one. I get it from below, mostly - one or two from the top (working wrench) - another wrench is locked on the other side (top or bottom)

Dave E

I think I heated a wrench with a torch and bent it 90 degrees allowing me to hold the head of the bolt on the header side( after about 20 minutes of frustration with the same problem you're having)good luck! Also , after an engine rebuild in my garage and many hours wrenching my 951, I just finally accepted the fact that some nuts and bolts can just take forever....

tt9714

I have good news to report...the crossover pipe is out! That is definitely quite a piece with all of the bends and connections. I look forward to reinstalling the updated version to simplify things in the future.

On the turbo side, I used a regular-length 15mm box end wrench to break the bolt loose then used a 15mm stubby box end wrench to take it out. The key was removing the O2 sensor which I thought that I could leave attached.

On the exhaust header side, the stubby box end wrench came to the rescue. It's amazing what a difference a few inches in wrench length can make.

keith

tt9714 - can you post a pic of the crossover now that it is removed? I can't fathom why the updated part would have made removal any easier - perhaps I am unaware of a very early version of the crossover...

tt9714

Keith,
Unfortunately I don't have easy access to a digital camera...however, I'll do my best to describe it.

The unit has three connections:
1) A dual port for the exhaust headers (6 fasteners)
2) A single, smaller port that goes to the wastegate (4 fasteners)
3) A large diameter port that directly bolts to the inlet of the turbo (4 fasteners)

All of this is assembled as a single piece that does a great job of wrapping around very back of the oil pan. Apparently it comes close enough to the bell housing that it must be removed for clutch repair/replacement.

What would make the job easier (and not require the top-end disassembly) is if the pipe that goes to the turbo was made of two separate pieces. For example, if the joint was between just after the oil pan and before the oxygen sensor this would allow removal of 80% of the crossover pipe with easy access to everything else.

Comments from someone who actually has the two-piece crossover?

keith

to the best of my knowledge, the only 2 piece crossover pipe differs from the '86 pipe in that it has a flange on the wastegate pipe so that the clutch replacement can be done without removing the crossover.

They should be the same at the turbo end...

Can someone verify/correct me on this?

Porsche-noob-91

Sorry to gravedig, but 21 years later I'm also taking out this pipe.
I'm wondering if I have to take out the wastegate to remove the 1 piece crossover pipe?

ecrouch01

You have to disconnect the crossover from the waste gate at a minimum. You could also disconnect the downstream side of the waste gate if easier and pull it with the pipe. However on my car the wastegate bolts were so rusty there was no chance they were coming out. I ended up cutting pipe to wastegate and having a v-band welded in. If your wastegates bolts are rusty you are in for some fun for sure.

Porsche-noob-91

I actually found out I did not need to take out the wastegate. Thank God, because it would've been a pain. The bolts are very rusted and 1 of the 4 leading to the exhaust pipe is snapped.
I just disconnected the cross-over pipe to wastegate bolts (x4), applied ample lubrication beforehand, and then wiggled the pipe out. Studs are very rusted, but hope that my new nuts will go on without a problem.

So to answer my own question: it is definitely possible to extract the cross over pipe (1 piece) on a 1986 turbo without removing the original wastegate!