Help removing nuts at exhaust header

[mjfeeney4]

Any suggestions on removing the 13mm nuts which attach the exhaust to the header? The appear to be copper and are slightly rusted. sprayed on liquid wrench this weekend. The 13 mm socket was too big due to rust removal but 12mm or 1/2" were too small.

Should I try hammering on the 1/2" socket? What about heating the nuts with a tourch first to make removal easier. I'm open to suggestions.

Mike Feeney

[Mr Project]

PB Blaster. Great stuff, seriously. Soak it and let it sit overnight. Other than that, yes, pound a 1/2" socket on, heat it up a little, etc. They get tough, but they're doable. Great motivation to spend the $12 for all new hardware before you put it back together! :)

[Kalevera]

I would use heat -- anything more than a little bit of resistance, and you need it. The metal studs are too soft and they can easily be destroyed (don't ask how I know).

Given that heat doesn't work (it should) and you have access to an air chisel, one should quickly remove that kind of nut.

By the way -- use PB blaster.

best, whit

[mjfeeney4]

I've never seen PB Blaster in the US, but then again I've been using WD-40 or Liquid Wrench. Is PB Blaster really different, that I should try to locate some before this weekend?

Thanks for the suggestions. I'm concerned about breaking the studs and then a simple flex disk replacement is going to get really complicated ( removing manifold or even the head)

[Bellicose Right Winger]

Try a six-point 13mm socket and heat from a propane torch. Be sure to use copper paste on reassembly.

Paul Shovestul



Any suggestions on removing the 13mm nuts which attach the exhaust to the header? The appear to be copper and are slightly rusted. sprayed on liquid wrench this weekend. The 13 mm socket was too big due to rust removal but 12mm or 1/2" were too small.

Should I try hammering on the 1/2" socket? What about heating the nuts with a tourch first to make removal easier. I'm open to suggestions.

Mike Feeney

[dacoyote]

AutoZone in Ohio carries PB blaster

[DanH]

My exhaust header had 12mm nuts. When I was removing them, 8 came off fine, 2 came out with the studs and the 2 by cylinder #6 were frozen, so the studs snapped off.

Now I need to get the remnants of the studs from my head. Good thing I was taking the head off anyhow... I'm getting some expensive craftsman drill out bits/extractor type things, they better work or else I'll have to get professional help(for my sanity).

[DanH]

I see you're doing the flex disc. When I replaced the center bearing on my car, to remove the exhaust, I just disconnected it at the output end of the manifold where the springs are. It was much easier than worrying about snapping an exhaust stud in the head.

I snapped one of the other bolts anyhow, but it is easier to deal with than one in the head.

Good Luck,

[LMUNick]

It may be a little late in the game, but I know this problem well. My father (factory trained BMW tech) had a great solution: shoot some penetrating oil on the nuts (wurth hhs 2000 is great). let it soak. Then use a 1/2" to 3/8" impact extension with a 3/8 drive impact wobble socket. you can use a 12mm and grind it out or hammer a 1/2" on to it. The 12mm will usually have a smaller diameter to allow more room agaisnt the pipe. If you have an impact, zap it a couple times, or use a big breaker bar and some elbow grease. Good luck!


Any suggestions on removing the 13mm nuts which attach the exhaust to the header? The appear to be copper and are slightly rusted. sprayed on liquid wrench this weekend. The 13 mm socket was too big due to rust removal but 12mm or 1/2" were too small.

Should I try hammering on the 1/2" socket? What about heating the nuts with a tourch first to make removal easier. I'm open to suggestions.

Mike Feeney

[Gene in NC]

Try a nut splitter.

[mjfeeney4]

Several posts have warned about breaking off the studs, and yes I'm removing the exhaust after the header (or manifold) because the bolts at the head looked even harder to remove.

Have others tried to use a tool to split the nuts on a 6 cylinder exhaust (M50)? It may turn out that after letting the solvent work on the nuts, they'll come off this weekend. It may be a tight fit but I'll purchase a nut splitter if it prevents breaking the studs and having to remove even more of the engine to have the broken studs drilled out.

Thanks for all of the suggestions.

[Kalevera]

Michael -- let me reiterate that the metal used in the OE fastener hardware is quite soft, and I've messed up threads (beyond using a die to fix them) and cracked flanges due to using some of these more "forceful" approaches. If it doesn't come off after a good PB soaking and a light wrench/socket, I'd get heat on it and it'll be off in a second.

best, whit

[mjfeeney4]

Lowell; Will go with your suggestion. Have sprayed with WD40 for a few days and will use heat before trying to remove them.

[LMUNick]

Just be careful to make sure that you don't shoot a bunch of wd-40 on right before you put the torch on it. wd-40 is super flammable.

best of luck!


Lowell; Will go with your suggestion. Have sprayed with WD40 for a few days and will use heat before trying to remove them.

[Robin-535im]

Is to *tighten* them a 1/8 turn before trying to loosen them. I learned this trick from Winfred and it really does work. There's much less chance of breaking anything, and all you really need to do is break the bond and it will back out really easy after that. I use this trick all the time now whenever I have a skinny little rusted nut or bolt. Just turn it in until it pops and breaks the bond and you're all set.

And please do try the PB blaster. It works. I've used WD-40 and Liquid Wrench for years and never thought they really did much, but PB blaster kicks butt! I used it on a rusty old O2 sensor after all else failed. Just let it sit a while, re-spraying and whacking the bolt with a wrench every now and then to let it settle in.

HTH

- Robin

[mjfeeney4]

After using PB blaster and letting it soak for a day the bolts came off easily. One problem though is that one of the studs came off with the nut. Was planning on just treading back into the manifold when replacing the exhaust.

Any suggestions on reinstalling the stud. Should I purchase a new one?

Thanks for all of the suggestions.

[Kalevera]

Hmmm...depends on how much trouble you want or need to go through with it. I'm assuming it's the 3 bolts per flange setup. You can probably get away with using two studs. If the threading's still good, it might be just as easy to replace the stud (I haven't done it -- I would probably try to find a good substitute).

best, whit

[Mr Project]

All of the hardware, nuts and studs, was under $20 from the dealer, IIRC. It's a no-brainer in my opinion. Make sure to use anti-seize when you install the new hardware and you're good to go for the rest of the car's life.