Thread: Exhaust Manifold Nuts Loctite or Loc Nut?

Loctite, spring washer and nylock nut wont work, The manifold gets to hot.

You need to remove the manifold and have the face machined. They bend.
Its not where the nut sits, its the side that goes onto the head.

Replace the gasket, all the studs and nuts, Use the correct nuts they are a flanged nut with anti rattle grooves on the face.

Have you done the rest of the mod with the manifold?

I did mine last weekend, and all has been good since.

New studs, new nuts, new gasket, cut the webbing out, enlarged the outside holes, and even gave it a couple of coats of VHT paint, just so it looks pretty.

The torque isnt much on these, but there is no real reason that it should have come loose again.

If you do look at using loktite or similar, it is going to have to be high temp stuff... that sheilding around the turbo is there for a very good reason.

If you're using this type it should be ok. Make sure to tweak the other 2 nuts to even out the load on the flange and studs, these studs have been known to sheer.

Not sure about the loctite, heat generally releases it's grip so I cant really comment whether it'll be effective.

Thanks guys,

I have used the flanged nut and have now checked the other nuts ,the top end one was loose so maybe now it might hold better.

Basil i haven't done the rest of the mods the manifold seals fine when the nuts are tight. We are leaving in two weeks for a 3 month trip with family and camper so i am watching this very closely.

Woko, i just mean't that there was advice to machine both surfaces as it was said that the angle of the surface from manufacture is not square so the nut does not sit flush, which might be my problem.

there is a high temp thread locking loctite you can get that will work in this application. trust me on this, dont use it.

while you have the exhaust manifold off for repair coat the threads very lightly with a silver antisieze then use the nuts as pictured above, better is to use the dome waashers and normal taper lock nuts.

I replaced all my studs with an equivilent bolt&washers...

So far is great, problems at all... and if anything did break in the future, alot easier to remover and replace.

Put a straight edge or spirit level on the side that bolts up to your cylinder head. That will tell you if its warped or not.

If it is you will see a gap between the spirit level and face of the manifold.

If its warped you will need to get it machined as it will keep blowing exhaust gaskets.

Both surfaces that bolt up together should be nice an clean, so a good seal forms.

You can get a specialist high temp lock nut from AFAIR boat suppliers.
They have a "floating" stainless steel disc at the top which jams onto the thread. They are specially made for exhaust applications.
I remember going to St peters in Sydney to buy them but I cannot remember the company.
I put them on my Porsche 924 Turbo as it had the same undoing problem.
Regards Philip A
These look similar
http://www.industrysearch.com.au/Pro...Lock-Nut-83648