Author Topic: Exhaust studs (Read 3935 times)

mwilderl · « **on:** January 05, 2012, 02:00:44 AM »

I've been looking to replace my exhaust studs that bolt the header to the head... however they appear to be 7mm. On pelican parts they have 6mm, 8mm, and 10mm and claim that the 8mm is for the m42. I cannot find anywhere that carries a 7mm stud. I've used a caliper to measure the studs as well as the measuring devices with all the different sizes that can be found at hardware stores to make sure that it's 7mm... Time to contact the dealer? Is the 7mm size normal? I'm assuming it is since i've tested 2 different heads that i have. I've also been to a local import auto parts store and they, just like pelican, show that the studs should be 8mm.

DesktopDave · « **Reply #1 on:** January 05, 2012, 07:16:18 AM »

I'm not sure myself, but I'd like to know as well. I'd personally just re-use them, but I'm a devoted cheapskate...

keflaman · « **Reply #2 on:** January 05, 2012, 08:04:31 AM »

I'm doing a "rustoration" and the exhaust system on my car has returned halfway to its natural ore-like state. I'm ordering hardware in advance and these are the part numbers I came up with. As you can see in the illustration the stud is an M7X45.

#9 Stud bolt (M7X45) (07-12-9-908-199)
http://bmwfans.info/parts/catalog/E30/2-doors/USA/318is-M42/LHD/M/1990/july/browse/engine/cylinder_head/

#6 Exhaust manifold nut (11-72-1-437-202)
http://bmwfans.info/parts/catalog/E30/2-doors/USA/318is-M42/LHD/M/1990/july/browse/engine/exhaust_manifold/

mwilderl · « **Reply #3 on:** January 07, 2012, 02:07:34 AM »

I ended up ordering all new ones from a dealer nearby, good to know that i'm not crazy and that it is indeed a m7! thanks

e30jr88 · « **Reply #4 on:** January 08, 2012, 10:52:16 PM »

Any ever use bolts instead of using those studs? I wonder what the size would be. I'm asking because its the last thing I need in order to finish my project and I don't think the dealer has any near by. The wait is like 3-4 business days

keflaman · « **Reply #5 on:** January 09, 2012, 07:25:49 AM »

My advice is to stick with the OEM studs simply for convenience. It will probably take just as long to chase your tail trying to find an M7 bolt of correct length and pitch as it would to just order them and be done with it.

If not in stock my dealer can usually get items shipped in the next day, however, he's 25 miles away:mad:.

e30jr88 · « **Reply #6 on:** January 11, 2012, 01:23:52 PM »

Quote from: keflaman;109514

My advice is to stick with the OEM studs simply for convenience. It will probably take just as long to chase your tail trying to find an M7 bolt of correct length and pitch as it would to just order them and be done with it.

If not in stock my dealer can usually get items shipped in the next day, however, he's 25 miles away:mad:.

Yeah ended up reusing the old ones just took them off and cleaned them up a bit rethread them and worked fine I hope still havent fired her up