PDA

View Full Version : Is there a gasket at the exhaust manifold/pipe junction?



Adnan
09-03-2004, 12:26 PM
Hi,

Does the M30 ('91 535)have gaskets between the exhaust manifold and down pipe? The ETK doesn't appear to show one at that point but does show gasket rings downstream.

I'm hoping to track down the source of the flapping noise and thought I'd start there.

Thanks,
Adnan

Jeff N.
09-03-2004, 01:11 PM
I don't think so. From memory, the down pipe bolts up the the manifold and has a flair type fitting. There are two studs in each manifold that connect to a slip ring on the down pipe. Couple things that might be helpful if poking around in there.

- the studs are this wacky tapered style. A loading spring sits behind the slip ring with a copper crush nut holding it all on. If you are going to mess with the nuts, soak them with PBblaster or something for a while before turning them. They can freeze on a bit and it's really easy to twist of that tapered stud. (don't ask me how I know this!!)

- from the bottom, you'll need a couple of long extensions with a flexi drive to get on the crush nuts. You can also reach them from the top. Either way it's a little hard to inspect the connection as it's way up there.

- there is a accordian like flex joint in the down pipe. Suppose that might have a leak if the metal has fatigued. Worth a look as well while you're down there.

Hope this helps...

Cheers!

Jeff

Adnan
09-03-2004, 04:08 PM
Hi Jeff,

Yes, this is most helpful. Thanks much.

Enjoy the looong weekend!

Adnan

Robin-535im
09-03-2004, 06:00 PM
Hi Jeff,

Yes, this is most helpful. Thanks much.

Enjoy the looong weekend!

Adnan

a good tip from someone a while back: after soaking the exhaust crush nuts in PB Blaster, tighten them a 1/4 turn before trying to undo them. This breaks the corroded seal between the nut and bolt and is less likely to torque the stud to bits than if you just start off trying to loosen it.

Craig
09-03-2004, 08:27 PM
Just buy extra studs, because odds are you will break one taking them off or putting them back on. They are cheap from BMA and good to have as back ups. There is no gasket.

DO NOT OVER TIGHTEN! I had no extras and ended up breaking one putting my car back together. It sucked, to say the least because these are not parts you can just find somewhere locally.

Jeff N.
09-03-2004, 09:19 PM
.

winfred
09-03-2004, 10:20 PM
it usually takes just this side of the hand of god to remove a stud from the manifold, drilling them and retapping bites donkey dick


Just buy extra studs, because odds are you will break one taking them off or putting them back on. They are cheap from BMA and good to have as back ups. There is no gasket.

DO NOT OVER TIGHTEN! I had no extras and ended up breaking one putting my car back together. It sucked, to say the least because these are not parts you can just find somewhere locally.

Craig
09-03-2004, 11:50 PM
Yup I had the machine shop remove the studs for $15.

mrbmw1
09-04-2004, 07:00 AM
Craig, they want to charge me $80 in Miami I plan to do it my self next weekend car runs like crap with this major exhaust leak

Craig
09-04-2004, 11:33 AM
Can you find a spare set of headers somewhere? Maybe a local junkyard or someone that's parting one out? Might be easier than trying to get them out yourself.