Went to a muffler guy today....

[AugustneverEnds]

Are there any shops in your area that specialize in European cars? I don't live really close to any of the DMC vendors so for the jobs I don't tackle myself I did some research and found a very good local Euro specialist. The PRV's exhaust really isn't difficult to remove just takes vast quantities of heat and patience. A competent shop should be able to help you out.

[Lou and "Boo"]

I never heated my exhaust manifold studs (which were rusted worse than that posted picture), and they unscrewed just fine with nothing breaking. A little AeroKroil helped. Just take your time. Quick jerks on the wrench will break it loose (no pun intended) but steady pressure will snap the stud/bolt.

[Rich_NYS]

The import shop where I live(Evia Auto) did the exhaust manifold gasket replacement on both sides of 10372. He lets the studs snap, removes the manifold, then uses a welding technique to zap a bolt onto the broken stud and easily backs the stud out. He has a few variations of the technique depending on how the stud snaps. He has done it a zillion times, enough to where he prefers the studs snap because it's easier for him.

When I do the exhaust on 4728, I'm going to do the work myself but will bring it to him to get the manifolds off.

[Bitsyncmaster]

When I can, I will MIG weld a nut onto a broken bolt and the heat (gets red hot) lets the broken bolt back out real easy. I've done that a few times to the transmission drain plugs.

[David T]

When I can, I will MIG weld a nut onto a broken bolt and the heat (gets red hot) lets the broken bolt back out real easy. I've done that a few times to the transmission drain plugs.

Nothing works better than an Oxy-Acetalyne torch on old, rusty exhaust hardware. You do have to be careful about the heat so you don't damage anything nearby. Even with that it is possible to pull the threads out of the aluminum. A Heli-Coil fixes that right up. Figure on a new set of studs and gaskets. If it has been leaking for a while you probably need to have the manifold ground flat.

[mluder]

I was pretty lucky. I did it with PB Blaster and a handheld propane torch. An impact driver is helpful as previously mentioned. Continuous pressure breaks bolts more often than a bunch of tiny impacts.

I soaked mine in Blaster for a couple of days. Just every so often went out to the garage and hit the nuts with a squirt. If they're real bad you can heat them with a torch first and then when hot spray the penetrating oil. Capillary action will help pull the oil into the threads. The only one I broke was because I had the driver set on revers and I actually tightened it instead of loosened. (Don't tell anyone).

Actually the most difficult nuts for me were the crossover pipe to the manifolds. Drives side is restricted access and didn't want to budge. IN the end heat, oil, and an impact gun won out.

Good Luck!
Steven

[dmruschell]

I recently helped a friend install a Stage 1 exhaust. I soaked the studs in penetrating oil on a regular basis a month before we tackled the job. We still broke a few studs. The good thing about the Stage 1 (as well as DPI's exhaust) is that they can make use of all 4 exhaust studs per cylinder, but don't necessarily need to. We could have broken every stud and still installed the Stage 1. I'd personally rather buy and install a performance exhaust myself than pay someone hourly to get the rusted broken studs out just to reinstall the stock manifolds.

[gamerguy51]

Wait a tick guys...why remove the studs if the nuts come off? Or is it a foregone conclusion that the nuts are seized? The studs actually are not very rusty...car has been garaged for 30 years and driven about 1000 miles in that time period...plus I think the exhaust was replaced in 01 at DMCH. I'll have to check my repair records to be sure. Also, how the hell are you supposed to get in there with a friggen MIG welder? I can solder, but i've never welded anything, much less manifold studs and nuts....You guys are scaring me. haha

[dn010]

It all just depends: Sometimes the nut will come off and the stud will stay, sometimes the stud will come out with the nut, and sometimes if it is bad they will snap leaving you with the rest of the stud down in the aluminum head. I just removed manifolds off a PRV over the weekend and all of the studs stayed in the head, nothing broke and it was a glorious day.

You are looking for a shop to do it so this doesn't matter, but for those who will be trying this yourselves, soak the nuts in PB or similar for a while, then heat the studs with a torch prior to your removal attempt (I like to run the engine before any exhaust work to heat everything up) and wear gloves. Before I had an acetylene torch, I've gotten by using a MAPP gas torch from a hardware store. Even if the studs/nuts don't look bad or just look like it has "surface rust", starting to wrench on them can turn into a nightmare real fast in some cases.

Exhaust work is right up there with "fixing electrical problems" in the things that I HATE doing column. I'd rather rebuild automatic transmissions all day long.

[DMCMW Dave]

Wait a tick guys...why remove the studs if the nuts come off? Or is it a foregone conclusion that the nuts are seized? The studs actually are not very rusty...car has been garaged for 30 years and driven about 1000 miles in that time period...plus I think the exhaust was replaced in 01 at DMCH. I'll have to check my repair records to be sure. Also, how the hell are you supposed to get in there with a friggen MIG welder? I can solder, but i've never welded anything, much less manifold studs and nuts....You guys are scaring me. haha

Take a close look at the studs, if they have rusted and are "thin" at the engine end they must be replaced unless you happen to like doing this job again later. If they are not rusted away, i.e. are full thickness, you can leave them alone but most folks would change them anyway.

Yours is not the usual case, typically people are dealing with original parts.