I'm in the midst of a clutch job on my 99 Forester with 170K miles. Thankfully, removal of the exhaust manifold was relatively uneventful. The only issue is that the studs unscrewed from the heads in three of the locations. Aside from surface corrosion on the exposed ends, they look to be in decent shape.

 

Is there any reason to use new studs and nuts? Also, should I use Loctite 271, which can only be removed once cured by heating up to 500F (260C)?

years ago i used to replace them...and now i just reuse them - the stud/nut combo's just turn into bolts, no big deal. some of the ones i replaced years ago then turned into bolts too! LOL i see no point in worrying about it anymore and i won't locktite anything in place because we have too much rust around here - would probably end up stripping threads once it's rusted and has to pull the stud out.

Is there any reason to use new studs and nuts? Also, should I use Loctite 271, which can only be removed once cured by heating up to 500F (260C)?

 

Loctite 271 wouldn't even work. Exhaust temps are about 800 F minimum. 1300 F is common on turbo's.

 

GD

I just reuse them - whether the nut came off or the stud came out makes no difference - I just remember which hole they came out of.

 

And I anti-seize the crap out of it!

As always, great info. guys. Thanks.

I just remember which hole they came out of.

i've never even done that, i just assume they're all relatively similar and visually appear that way. but that is really good advice, never thought of it.

 

occassionally you'll have one that mangled a bit of thread, chasing it with a tap is a really good idea (regardless of whether or not you use new or old studs).

kind of an unrelated question...sorry.... but wont anti seize also burn off at high temps?

kind of an unrelated question...sorry.... but wont anti seize also burn off at high temps?

 

Don't truely know. I often use high temp stuff I put on my diesel glow plugs.

 

I did have to pull the engine(s) in a 99 Forester a few years ago 3 times (bad engines - what a nightmare). I use it on all eng/trans bolts, engine supports, etc.

 

Certainly can't hurt.