Exhaust manifold studs: How tight?

e30jake · 06-26-2012, 10:39 PM

So I finally got some inspiration to work on putting another m42 in my 318is. Bought it with a blown engine and it has just been sitting since then. I'm planning on putting the exhaust manifold back on tomorrow. I have brand new studs for it and tightened them finger tight, which was different for each hole. I was in a hurry and didn't think about cleaning the holes out which could have been a factor. So how tight are they supposed to be? Are the threads in the head short enough it should just bottom out by finger tightening or what?

e30jake · 06-27-2012, 08:08 AM

Anybody?

nando · 06-27-2012, 08:12 AM

hand tight is fine.

cormier · 06-27-2012, 08:14 AM

Clean the holes, use loc-tite, and use two nuts against each other to tighten the studs

Not sure the spec, but I would say just over hand tight (maybe 30 ft lbs) should be fine with loc tite

e30jake · 06-27-2012, 08:17 AM

Thanks!

nando · 06-27-2012, 08:32 AM

I'm pretty sure you don't want to loctite exhaust manifold studs in place.

cormier · 06-27-2012, 11:49 AM

I've always heard to use it.. I'm sure it would be fine without as well

Some info on this thread if you wanted to do some reading

http://m3forum.net/m3forum/showthread.php?t=397602

A simple google search produced many many results about exhaust studs, BMW or otherwise

06-26-2012, 10:39 PM	#1
e30jake Mod Crazy Join Date: Feb 2012 Location: Harrisonburg, VA Posts: 634	Exhaust manifold studs: How tight? So I finally got some inspiration to work on putting another m42 in my 318is. Bought it with a blown engine and it has just been sitting since then. I'm planning on putting the exhaust manifold back on tomorrow. I have brand new studs for it and tightened them finger tight, which was different for each hole. I was in a hurry and didn't think about cleaning the holes out which could have been a factor. So how tight are they supposed to be? Are the threads in the head short enough it should just bottom out by finger tightening or what? __________________ 88 325 2.7i- DD 69 2002- m42 swap/resto project

06-27-2012, 08:08 AM	#2
e30jake Mod Crazy Join Date: Feb 2012 Location: Harrisonburg, VA Posts: 634	Anybody? __________________ 88 325 2.7i- DD 69 2002- m42 swap/resto project

06-27-2012, 08:12 AM	#3
nando Moderator Join Date: Nov 2003 Location: bellingham, wa Posts: 25,600 Images: 2	hand tight is fine. __________________ Build thread R3v helped me raise $3000 for cancer research

06-27-2012, 08:14 AM	#4
cormier Grease Monkey Join Date: Feb 2008 Location: Mississauga Posts: 385	Clean the holes, use loc-tite, and use two nuts against each other to tighten the studs Not sure the spec, but I would say just over hand tight (maybe 30 ft lbs) should be fine with loc tite __________________

06-27-2012, 08:32 AM	#6
nando Moderator Join Date: Nov 2003 Location: bellingham, wa Posts: 25,600 Images: 2	I'm pretty sure you don't want to loctite exhaust manifold studs in place. __________________ Build thread R3v helped me raise $3000 for cancer research

06-27-2012, 08:17 AM	#5
e30jake Mod Crazy Join Date: Feb 2012 Location: Harrisonburg, VA Posts: 634	Thanks!

06-27-2012, 11:49 AM	#7
cormier Grease Monkey Join Date: Feb 2008 Location: Mississauga Posts: 385	I've always heard to use it.. I'm sure it would be fine without as well Some info on this thread if you wanted to do some reading http://m3forum.net/m3forum/showthread.php?t=397602 A simple google search produced many many results about exhaust studs, BMW or otherwise __________________