DIY exhaust rebuild?

[DarkMatter]

I've got a 987.2 Cayman, 2.9 litre. I've been advised that I should have the exhaust stripped and reassembled from the triangular manifold flange back to tail pipes to replace corroded bolts and brackets (the cats and silencers are fine). I intend to do this myself.

Does anyone have first hand experience of doing this job on their Cayman/Boxster, what advise can you give?

Thanks

[edc]

Be careful with the hammer or you may damage the cats, get some penetrating fluid to help ease the rusty bolts. If you have to remove the manifolds be well prepared as the bolts will easily snap in the head.

[Trev450]

If you don't have the facilities to work under the car in comfort and also have access to a good blow lamp, I would think twice about doing it yourself. I had my indy change mine back in the summer and he managed to snap seven of the twelve bolts going into the head. This is a guy who has done this job countless times before, but warned me in advance that a good few would shear and that the labour charge for the job would then increase accordingly.

[DarkMatter]

Thanks.

Thankfully I was told that the manifolds (and the manifold to gead gaskets) do not require any attention as they are in good rust free condition.

It appears to me that it is the manifold to cat flange that may be the most difficult, looking at the PET diagram it appears that there are 3 loose bolts and nuts on each flange (well rusted on my car), rather than 3 studs and nuts for each one - does that sound right?

[Trev450]

DarkMatter said:

Thanks.

Thankfully I was told that the manifolds (and the manifold to gead gaskets) do not require any attention as they are in good rust free condition.

It appears to me that it is the manifold to cat flange that may be the most difficult, looking at the PET diagram it appears that there are 3 loose bolts and nuts on each flange (well rusted on my car), rather than 3 studs and nuts for each one - does that sound right?

Yes you have three nuts and bolts on each manifold to cat flange, but the bolts that retain the manifolds to the heads also rust away and will more than likely need replacing as well. This is when the fun and games can start as unlike some other cars that have studs with nuts on them, Porsche use flange-head bolts made from mild steel and it is these that if/when they shear will need to be drilled out and something along the lines of Time Sert thread tubes used to replace the damaged threads.

Edited by Trev450 on Tuesday 10th November 16:55

[Demort]

If the flange bolts are original ones then they are press fit (flat head with a spline).I use oxy/acetelene to heat whats left of the nuts then chisel them off then heat the back of the stud houseing and knock them out , its a ramp job really but i guess it could be done on axle stands.
You could use some sort of blow torch but to be honest the key is getting it hot enough and dont forget your close to various items that will burn .. i would advise getting a garage to do them to be honest.
Im sure people here have indeed done them at home but its not a job i would recomend to attempt purely on a safety asspect.

Edited by Demort on Tuesday 10th November 19:35

[DarkMatter]

Thanks Trev450 and Demort, I think that you've convinced me that it's a job best done by my local Porsche specialist.

[AndrewsCayman]

I had mine done under warranty when the 3 flange bolts corroded fianlly let go while on the way to Le Mans this year. My message is: don't delay getting them done, because a bit of enthusiastic acceleration one day will blow the rusted remnants apart at an inconvenient moment! It was a long droning trip back home with one side of the exhaust blowing all the way...

I suspect the OPC found replacing them relatively easy because they had it done in half a day, unlike some of the other jobs like water pump, steering pump, battery (2 days!!!), window lifters etc etc which all seemed to be "difficult" jobs.

[Demort]

AndrewsCayman said:

I suspect the OPC found replacing them relatively easy because they had it done in half a day, unlike some of the other jobs like water pump, steering pump, battery (2 days!!!), window lifters etc etc which all seemed to be "difficult" jobs.

Exhaust studs take about 2 -- 2.5 hrs to do if you are removeing and replacing the clamps as well , but a water pump/window lifter is kinda an hour and a half job