Exhaust bolts - Advice needed please - Aaaaaghhhhhhh!!!!!

squelch · 11 Apr 2018

Today I finally had some time to get the bypass pipe fitted and so I set about removing the centre silencer...

I don't think Porsche could've found any poorer quality exhaust nuts & bolts if they'd tried! I've seen better condition exhaust fittings on a 20 year old Ford! The corrosion is ridiculous and they've seized in place.

However, I've managed to remove all but the upper two (one on each side) and wondered if anyone had any pearls of wisdom for removing these - they're the ones tucked up above the pipe (on the flanged join). The surface corrosion means a socket or spanner cannot get enough grip on what's left of the nut and the tucked-away position means I've got little to no hope of drilling them out....

Any advice would be much appreciated - thanks! :thumb:

FZP · 11 Apr 2018

Having done this myself I can tell you I feel your pain. I used the following tools to get it done.
DREMEL
RECIPRICATING SAW
SMALL ANGLE GRINDER
HEAT GUN
LUMP HAMMER
MASONRY CHISEL
HOLE PUNCH
The best I can suggest is that you try and cut the bolt off as close to the flange as you can with what you've managed to get your hands on. It's not easy and turned a 3hr job I to a day and a half for me. But if you have a sympathetic mechanic near by, give him a call and see if he'll remove the remaining 4 bolts for you. The rest you can so yourself. Also go and get 2 new exhaust gaskets along with 6 new stainless steel bolts washers and nuts.
Good kuck

squelch · 11 Apr 2018

Thanks FZP!

Luckily the bypass pipe came with new gaskets (and nuts & bolts, zinc plated but not stainless, so I think I'll replace them).

I've got all the others off, so it's just these last two that are proving elusive - I'll persevere... :sad:

FZP · 11 Apr 2018

Here is my thread from when I changed over the exhaust from std to Tubi. **** of a job.
http://911uk.com/viewtopic.php?t=123776&highlight=tubi
Just thank your lucky stars that you're not trying to get at the cat bolts :sad:
Edit:Just went back and realised you do need to get the cat bolts. :sad: :sad: :sad:

ayton1 · 11 Apr 2018

Just changed mine last week, I ended up warming them up with torch & then
Sharp chisel to chop nuts off. Bolts then knock out with punch.
If you have top gear pipe you will have to drill holes a little larger in cat pipes
& the support brackets, As bolts they supply are to big. Or better still get some 8mm stainless steel ones.

squelch · 11 Apr 2018

FZP said:
Here is my thread from when I changed over the exhaust from std to Tubi. **** of a job.
http://911uk.com/viewtopic.php?t=123776&highlight=tubi
Just thank your lucky stars that you're not trying to get at the cat bolts :sad:
Edit:Just went back and realised you do need to get the cat bolts. :sad: :sad: :sad:

Thanks for the link - I'm just about to read it now.
Indeed, it's the uppermost cat bolt on each side that I just can't get to...

ayton1 said:
Just changed mine last week, I ended up warming them up with torch & then
Sharp chisel to chop nuts off. Bolts then knock out with punch.
If you have top gear pipe you will have to drill holes a little larger in cat pipes
& the support brackets, As bolts they supply are to big. Or better still get some 8mm stainless steel ones.

Thanks ayton1 - Yes, I think I'll get the 8mm SS nuts & bolts (if I ever get that far :sad: )

chaser · 11 Apr 2018

Had my car in to OPC for major service today. the mechanic remarked on the state of the nuts holding the exhaust together,and told me they gas torch them and use mole grips to get the old ones off. The young lady on the desk rang me with a quote to replace them all ...... £1000

I`ll be tackling that job myself then. :wink:

Clanky · 12 Apr 2018

I had the same issue when fitting the Capristo.
I ended up cutting the rusty blobs off with a dremmel & cutting disk & using a small chisel on the remainder. Also managed a couple of the better ones with a nut splitter.
I also bought a small sprung loaded pipe wrench type tool which helped access the difficult nuts.

It looks as if the original manifold studs are stainless or ti, as there was no corrosion on them.
When putting them back, I used brass nuts to avoid corrosion & make it easier to dismantle in future.

Callughan911 · 19 Apr 2018

I have seen these worn even on 991's that are a couple of years old, something to check before purchase?

John997 · 21 Apr 2018

Re: Exhaust bolts - Advice needed please - Aaaaaghhhhhhh!!!!

Hiya, I went throiugh the pain as your goodself, its quite soul distroying really.... used all the tools as peeps have mentioned but what I found on the flange joint between Cat & Manifold - these 3 bolts, welll the heads werer tag-welded to the flange !!

Generally they are a splined bolt so as long as you get most of it out you can tap/bang the rest out, I think in your case mate and the awkward position is to get someone to plasma cut the fecker out - thats what I did...

I spent a good couple hours on one bolt !!!, got a few of these out then I eventually got a Paul out (PCW) to cut the others out - so time scales...

Flange bolts, muffler bolts (all round) took about 1.5 hours if that and to replace with SS bolts.

All the best and sure you will get it done.

Cheers, John

squelch said:
Today I finally had some time to get the bypass pipe fitted and so I set about removing the centre silencer...

I don't think Porsche could've found any poorer quality exhaust nuts & bolts if they'd tried! I've seen better condition exhaust fittings on a 20 year old Ford! The corrosion is ridiculous and they've seized in place.

However, I've managed to remove all but the upper two (one on each side) and wondered if anyone had any pearls of wisdom for removing these - they're the ones tucked up above the pipe (on the flanged join). The surface corrosion means a socket or spanner cannot get enough grip on what's left of the nut and the tucked-away position means I've got little to no hope of drilling them out....

Any advice would be much appreciated - thanks! :thumb:

Exhaust bolts - Advice needed please - Aaaaaghhhhhhh!!!!!

squelch

Imola

FZP

Zandvoort

squelch

Imola

FZP

Zandvoort

ayton1

New member

squelch

Imola

chaser

Suzuka

Clanky

Suzuka

Callughan911

Monza

John997

Silverstone

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