Exhaust Manifold Nut coming loose

[fiftytakedowns]

On #1 the exhaust nut consistently Is coming loose, at first it was the stud, but after finding different studs with the shoulder on em it wasnt an issue. now the nut keeps comin loose? Im thinking a lock washer? Any other input?

THanks. Im getting sick of the exhuast leak.

[c.d.iesel]

copper exhaust self locking nut and flat washer

[1453aalapapa]

you should try 18 10 7 523 805. this is a flange nut(looks like a nut and a washer together) used on the v8's. it is heftier than the other exh nuts, but the neatest design of this nut is that it has an alloy helicoil. i used these on my mitsu galant vr4. the 4g63t engine is notorious for breaking exh studs. what happens is the heat cycles makes the nuts back off, and the vibrations crack and break the studs. with this nut, i think the alloy helicoil tightens up with heat. i never had broken studs after switching to this nut, and lots of my friends who also switched noticed it stopped the breaking studs.

[Pinepig]

Don't use the kind that CD posted a picture of, you want the ones that look like the top on the nut was squished sideways. The ones I get local have a flange on the bottom and I have to grind that part off because the stud is a little to close to the pipes.

Oh BTW once your gasket leaks once you might as well pull the main and put new ones on, it'll start leaking again in no time.

This is one of the prices you pay when you turbo.

[Guest Anonymous]

IMHO, either kind works fine. You could add some high temp loc-tite if it still loosens, but I usually go the opposite way, and put some anti-seize on them so they come off easier the next time I want them off.

[c.d.iesel]

http://www.wurth.com.au/catalogue/A09_7311.pdf

[fiftytakedowns]

Don't use the kind that CD posted a picture of, you want the ones that look like the top on the nut was squished sideways. The ones I get local have a flange on the bottom and I have to grind that part off because the stud is a little to close to the pipes.

Oh BTW once your gasket leaks once you might as well pull the main and put new ones on, it'll start leaking again in no time.

This is one of the prices you pay when you turbo.

Did you mean Pull the manifold and put in a new exhaust gasket?

So far, I havent had any trouble with exhaust leaks once I tighten it up, but the nuts loosen relatively quickly after each heat cycle, which is frustrating

If I can find one of those in 12 MM I will jump on it and keep em as spare.

Another issue is the vibrations.. but as I am tuning the car they are slowly becoming less prevalent. I scheduled some dyno tuning time to make sure I am accurate as far as my AFR's or Timing, I get some m,isfiring at cruising speeds, and cant tell if it is timing, or fuel, acuse as I adjust either it doesnt change anything

[Pinepig]

http://www.wurth.com.au/catalogue/A09_7311.pdf

Thanks CD,

The middle one is what I use and have had the best luck with.

[Guest Anonymous]

Where can I find those Nuts?

[Pinepig]

I got mine at FPS right here in Sacramento ( foreign parts specialties ).

[fiftytakedowns]

The Damn STuds and NUTS keep on coming out. They thread in, and will stay in, but after a couple of Days the stud comes out, and shoots oil everywhere, and fucks my day up.

Should I use plumbers tape on the studs? a special loctite? I really cant figure out why it comes loose all the time.

[Colin]

The Damn STuds and NUTS keep on coming out. They thread in, and will stay in, but after a couple of Days the stud comes out, and shoots oil everywhere, and fucks my day up.

Should I use plumbers tape on the studs? a special loctite? I really cant figure out why it comes loose all the time.

You're supposed to use the thread sealing kind of locite on them.

[fiftytakedowns]

not high temp resistant loctite?

[Colin]

not high temp resistant loctite?

http://www.bmw2002faq.com/content/view/19/32/

[tjones02]

Loctite 5770... for your extreme application.

http://www.fastenal.com/web/products/detail.ex?sku=0608690&ucst=t

Otherwise, I use normal red loctite.

JP should easily be able to get the copper lock nuts that Charlie describes.... might even have them in stock.

http://realoem.com/bmw/partxref.do?part=11-62-1-711-954

I have seen the Mercedes style 12mm wrench size before but don't know if the usual wholesalers like SSF or IMC carry them. I'm not at the shop computer to be able to check. Würth obviously has them, but usually require a minimum order, and only through a shop with a wholesale account like JP's A1-Imports.

As for studs, you say you've installed the shouldered type. Those are good for your application.

On reusing the gasket... once the hot exhaust goes past a leaking gasket it is compromised and usually thinner than the areas where hot exhaust has not gone past it. Only on rare occasions have I ever been able to get away (long term) with reusing an exhaust gasket that has been leaking as you describe.

Cheers and HTH,