Exhaust Manifold Studs

M&K · Post by **M&K** » Mon Apr 16, 2007 10:30 am

Due to a broken stud I had them all replaced last year. a couple of months ago I replaced half the exhaust sytem with a stainless one, the 1st stud has now come out and I have found the thread in the engine block has gone, any thoughts on this problem would be appreciated.
Also, is there a Bongo friendly garage in the Birmingham Area ?

Best Regards

Mike.

Veg_Ian · Post by **Veg_Ian** » Mon Apr 16, 2007 11:21 am

Have you thought about a helicoil insert? Most garages should be competent at fitting if this is all you have in mind.

haydn callow · Post by **haydn callow** » Mon Apr 16, 2007 12:19 pm

Spot on veg_ian

mikeonb4c · Post by **mikeonb4c** » Mon Apr 16, 2007 12:46 pm

Didnt I read that this tended to happen when the exhaust manifold had become distorted due to an episode of overheating. The problem then was that you could but a new stud in but it was still likely to shear or pull out the new stud due to the strain exerted by trying to hold a warped manifold in place. I'm not a techie so cant comment personally, but might be worth seeing if an experienced BF person comes back on this one.

Good luck - I'm sure it is all very sortable.

Mike

Veg_Ian · Post by **Veg_Ian** » Mon Apr 16, 2007 1:02 pm

That's very likely Mike. All exhaust manifolds can warp or crack due to the nature of their composition (cast steel) and the continual heating up to high temperatures and cooling down cycle. Just like with the cylinder head you should always check for level if removed. The more recent multilayer gaskets help but not enough if you've a banana shaped manifold!

mikeonb4c · Post by **mikeonb4c** » Mon Apr 16, 2007 1:34 pm

Can they be skimmed or ground flat if so, or is that not a practical option veg_ian?

Veg_Ian · Post by **Veg_Ian** » Mon Apr 16, 2007 1:47 pm

Well they should be skimmed but a mate of mine once used a flat paving slab, chalked it and rubbed the manifold face over it to reveal the highspots then used a grinder to rub them off.

Not very scientific but it worked and no doubt saved a fair few quid

having said that, it depends upon the extent of the distortion. It obviously wouldn't work for extreme cases.

mikeonb4c · Post by **mikeonb4c** » Mon Apr 16, 2007 3:02 pm

Wow! And I thought I was a £ watcher.

Veg_Ian · Post by **Veg_Ian** » Mon Apr 16, 2007 3:19 pm

Mike, you a £ watcher !!!

Shock horror, I would never have guessed

I'll let you into a secret, I hate spending money on cars as well.

M&K · Post by **M&K** » Thu Apr 26, 2007 5:09 pm

Thanks folks, helicoils and new studs did the job, the garage had all the answers.

smartmonkey · Post by **smartmonkey** » Fri Apr 27, 2007 10:05 am

Veg_Ian wrote:That's very likely Mike. All exhaust manifolds can warp or crack due to the nature of their composition (cast steel) and the continual heating up to high temperatures and cooling down cycle. Just like with the cylinder head you should always check for level if removed. The more recent multilayer gaskets help but not enough if you've a banana shaped manifold!

If they were cast steel there wouldn't be a problem but sadly they use cast iron.