The joy of removing a rusted exhaust.

So yesterday I began the job of removing the stock mufflers and cats. I thought I would share a couple of pics of what I had to work with This is on a 68K UK car. Most of these bolts snap immediately. In fact for some of them that's pretty much how I was hoping it would work out (and it did). Some of the bolts are so rusty that they just flaked away to be some kind of dome. But check out the studs from the catalytic converter to header flange - there is almost nothing there. What sized socket for that lol!

That sucks man. I try to avoid northern cars for this reason, at least with 996s, the exhaust bolts/nuts (and maybe some clamps and a couple of studs for fender liners, etc.) should be the extent of your "problem" areas, with a BMW of that vintage, everything would be falling apart....

on on 1999 car ! this car must have seen quite some bad weather.. probably staying very close to the ocean or driving in the snow. On my 2003 from dry Texas, all the bolts are like new. That's where you see that the discount for northern car is important, and often you'd better go the extra mile and pick on down south... far from the coast

Pretty much all the cars I looked at here in the UK were like this. The exhaust hardware is definitely the worst, although I am sure I will battle some of the suspension hardware when the time comes. PB buster is my new friend - but I do now own a reciprocating saw, thanks to this job.

Things are coming along better this morning. Cats went on well and the muffler lined up with the cats nicely and the tip lined up well with the apace in the bumper too. Before I can finish I have to fab a new sleeve for the 70mm bolt on the other muffler mounting plate as the old bolt was seized in the old sleeve. Given the conditions here I have gone with all stainless steel hardware other than the replacement factory parts.

Very nice.

Looking good. So far, I have found similar rust primarily on the exhaust hardware, but not as bad as yours. My Porsche has 52k miles, so that's probably why.

I wish I had that stainless setup under my car!

thats perrrrdy!

Had the same thing on the header/cat flanges on my exhaust. Be glad you were putting on new cats. The "bolts" on the cat flange are actually pressed into the flange, just studs with no heads. It took me a couple of hours to drill them out on one side to install stainless steel bolts. Left the other side attached. I did this when dropping my engine.

All done. Dharn yeah, I'll hang onto the original cats and remount them for some dyno comparisons so I'll take them to general workshop and have them press the studs out and drill to 10mm so I can use regular bolts when I remount them.

looks nice how does she sound?

are those the supercups? or the Maxflows? :-) edit.. not supercups.... so Maxflows? lets hear a sound clip!

Hi OZ951, A fellow UK member!. Where did you get the Fab M8 and how much if you dont mind my asking looks GR8.

P.s I found the quickest way of getting these rusty B's off is Drill through em.

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Yes the mufflers are maxflows. As for how it sounds I'll let you know my views on that after I have been able to drive it for a while.

I took this picture a few weeks ago of my 94k mile car, it's lived in Florida and North Carolina since new -plug- it's for sale! I still say you're super lucky it's not a 90s BMW though, that car would fall apart in your hands if you looked at it wrong...

I'm jealous (of the clean condition). It's amazing the difference in condition between cars in nice climates and those that have to deal with salt grit. I need to get my car back to Oz! I look at the earth cable on my engine and I wonder how the thing starts. I'll get to it sooner or later.

Nice work, I'm sure worth the effort!

Hey thanks, after owning several northern cars, I try to avoid them now. I do use my cars for ski trips, but if they ever see snow, I try to wash the underbody right away. Here in central North Carolina it may snow an inch every few years, so at least no long term exposure to salt. As for the ground strap, the 996 doesn't seem to be that sensitive to grounding issues thus far from my experience like 944/951s were, but of course clean grounds wouldn't hurt. I actually cleaned the strap on one of my earlier MK1 996's, didn't seem to make much of a difference.

Have you ever skied at Beech Mtn?

So I dropped the car in to a workshop today so they can deal with the header bolts, odds are they will have to drill some out i'm guessing. So it will be all stainless steel when it comes back on Friday - that will be nice.

I picked up the car from Gantspeed today, that's the Porsche restoration specialist I took the car to to remove the rusted bolts. In the end 8 of 12 header bolts sheared off. Not pretty. So 9.75hrs of labour to sort out those bolts and four equally nasty bolts on the muffler brackets. I'm glad to see them gone. (not quite as glad to see half a dozen C notes gone but hey, I still have my sense of humour and no busted knuckles. More detailed pics are on my web site. Heading back to the dyno on Tuesday to get some more numbers. I haven't decided exactly what exhaust components I will have installed for that next dyno run. I'll think about that over the weekend.

Wow! nice and shiny, looking good. How does it sound?

Very nice !

I found a nice set of (used for two weeks) Fabspeed mufflers for a decent price.... Are they really loud?

Very Sexy. Hot Hot Exhaust ****.

very nice! enjoy the new sound!

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Oz, Can you tell me how they removed the sheared manifold bolts? I just snapped 4 removing my old exhaust manifolds. Thanks, Peter

I broke allso 8 of the 12 bolts. plus 2 on the mufler holder bracket. I drilled those out. We tryed to weld nuts on them, but the metal on the bolts is pita. When heated they will be hardened and when you try to turn those open, it will snap of again. If you weld them, and they dont come loose you will need special drils to get thru. Here's some pictures of my winter project, i allready had the engine out for ims and rms work. http://speedrii.kuvat.fi/kuvat/possu/P1030718.JPG

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LOL I guess it's the car **** equivalent of taking it in the rear...

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G'day Pete, they were drilled out and then heli-coiled.- Good luck. it's a PITA job.

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Thanks Oz. I figured this would be an interesting job. BTW-your website is awesome....

Im currently in the middle of a exhaust manifold replace job. It is an absolute PITA. I have also tried welding new bolts on but when torque was applied, the bolt would snap at the weld... My next move is to use a dremel with a grinding stone on, grind the rusted heads off the bolts and then drop the manifold off. Hopefully I should be left with just enough of the stud to use a pair of mole grips to twist it out... If that doesnt work then i will hand it to the pros...

Hey guys I need some sympathy here.. An easy job which takes about 1.0 hour has turned into a mess. Snapped four manifold bolts, tired to drill them out and use an easy-out thinking I might be able to back them out. Snapped the easy-out in one of them. I am going to have a drink now and wallow in my pain.

pmkazz, I know what you mean. I broke 10 bolts, 8 on the manifolds. I have been drilling those out approx 8 hours And my engine is out of the car.... Still have one to go. Those easy outs wont help you. Bolts sit really tight in the heads. Best thing to do if (when) this happens, is just drill those out. You need to get a carbide drill to get thru the easy out... If you are getting realy pissed of, take the car to some proshop and let them deal with it... Saves your nerves

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Thanks Pete, "an interesting job", now that's an understatement. Sorry to hear about your current predicament. I hate to say it but when I hear about yours and everyone elses trouble with these bolts I am really glad I just took it to a shop for the bolt extraction. If it makes you feel any better I paid �675 to have 16 bolts dealt with (I had them replace the lower muffler bracket bolts as well). Well, it's time to begin a job of my own on the car today, so I best get cracking. Good luck.

Thanks Speed rII and Oz. Misery loves company. And yes I think it will be a visit to my Porsche shop as I can foresee my patience running thin

Sharing my pain and looking for some tips really. I am also in the UK with a 90K miles car. Everything was rusted up at the back, but I'm working through it. Silencers removed once I had either snapped the mounting bolts or dremel'd through the nuts - then pushed the bolt up and hack sawed through the head. Angle grinder to the sleeve bolts and cat bracket bolts and dremel to the silencer nuts. With silencers off angle grinder through the tip clamp bolts. But some seem to be made from toughened steel and only a grinder will get through - in a really tight space. I'm now on the cat to manifold flange, I managed to simply cut the heads off the ones you can see in this photo (left side) and they knocked out. But with the right hand side the bolt heads and nuts are gone - rusted away, but the bolt remains in the cat part of the flange with seemingly just enough rust to completely hold the cat to the manifold (although not enough as the flanges are leaking which is why I want to put a new gasket and bolts in). I've tried pounding the remains of the bolts in the flanges, but they are definitely now moving and I don't want to pound too hard for risk of cracking the manifolds. Next plan is to remove rear bumper, heatshields, both silencers, the CAT I can get off then I'll have as about as good access as is possible to try and move the remaining CAT too and fro in the hope the bolts start to give... Lee ps, dear Porsche AG, these cars cost $100,000 when new. Do us a favour and put stainless fasteners on in the future. Most of us don't track our cars so stainless, whilst not as strong, will do just fine.

I just removed both mufflers to get at my plugs. The mufflers came out via loosening just the 3 bolts facing the coils which were not corroded. (NO need to remove THE LONG BOLTS). Then snapping off the four bracket bolts at the rear along to the cats and sliding out the muffler from the clamps. I got replacement bolts for those at the local Hardware store and plastered them with 'easy off' crap. I had PB blaster on the clamps bolts for 24 hours and still I had to snap them off. Hey guys----The Long bolts could have been easier to remove when the muffler was off on the floor. Unfortunately where ever you live in the UK you are not much more than 50 miles from the ocean.