E34 Exhaust manifold problem - 535ia/E32 735ia

[genphreak]

Hey all,

Here's a challenge! You think you know your car, but how well can you picture your exhaust manifold and engine pipe? Few of us ever go down there... but here is a curve ball to ponder...

Last year I took my baby to the exhaust shop for a stainless steel exhaust and new catalytic converter, complete with engine pipe (original BMW part).

When they removed the old engine pipe from the exhaust manifold, they broke the flexible joint which was a part of the cast iron manifold. That means that the manifold is toast as one can't weld cast iron normally. They did a bodgy repair to get me out of the shop, jerry rigging a piece in between - which now sounds like its only got very little more life in it!

As such, I recently took it back to the shop and asked them to fix the mess. However in Australia a rough job is sometimes considered alright, especially if it is 'knock off time' (ie 4pm; time to head for the bar for a beer) and the shop said; 'the stainless steel was rusted' and that it just broke, 'its not our fault', (Bloody BeeEmTroubleUwes they said) etc. and wouldn't fix it.

Now when they put the new exhaust on (I remember seeing them break at the time- they were twisting and wrenching the poor thing like they wanted it to break. However I didn't think it'd be very hard to fix up later - I figured once these monkey's were done I got out of there, I'd fix that but up. It was the worst I tell you... I could barely watch... don't you just hate it when other people work on your car???

So now the joint is getting more and more noisy, and out of interest I checked cost of a new manifold.. (normally the fix would be to weld a new joint, or even a straight piece of pipe instead, but if you cannot weld cast iron what do yo do? I imagine BMW have some hell- welding process to do it...

Ouch... it was beginning to feel expensive, the stealer quoted $963AU (750US)... could buy headers for that... still that's no option cos I don't have the cash...

So back to finding a more straight forward fix, which is where I need your help; On ebay there are some 2nd hand manifolds and perhaps I could one of get these, but looking closely I notice they have no flexible joint- so I'd still have to get my stock engine pipe modified...

Furthermore, looking at the manifold in the BMW parts list (ETK), a seemingly different exhaust manifold is listed, with the flexible joint a part of the engine pipe, down further away from the engine.

The ebay manifolds can clearly be seen with engine pipes attached and look just like the parts list version, except they seem to have had the flexible link described in the ETK entirely removed (btw, interestingly on our cars only one pipe has this flexible joint; with these ebay ones you can see where it was and how they have welded the new pipe in).

Has anyone else had trouble with these joints? Do we just get rid of them when they fail or break?

Perhaps one of you has seen one like mine; with the joint a part of the exhaust manifold as standard...

Maybe I am wrong and my manifold can be welded somehow... perhaps I will have to replace my manifold... hmmm.. As ever, any comments could be worthwhile.

If anyone got a spare E32/E34 M30 exhaust manifold hanging around the shed I'd love to know!

Many thanks in advance,

GP

[pundit]

Hi Genphreak,

Where abouts in OZ are you?

Try these guys in Melbourne...

BMSPARES

Good Luck!

BTW - I'm not certain, but I think you may find differences in the manifolds between L/H/D and R/H/D cars.
Remember the steering box on our Oz E34's sits close to the exhaust manifold. In the U.S. it's on the opposite side. I think that may result in some differences.

[Mobius]

Having just dropped my exhaust to get at my O2 sensor, I can say with no reservation that the flexible bits are not a part of the manifold.

See the pic I took:


I know on other cars I've seen this accomplished with a steel-braided sleeve bit.. I'm sure it could be welded in.

[winfred]

i've never had a problem with the flex joint on a 535/735 exhaust, the ones on a m20 525 can break varly easy, i can only guess they abused it getting the system out, i am not sure about the cars over there but on the usa cars head pipe/cat a 735 and 535 will interchange so that may add to the cars you can scavage from

[genphreak]

Hey Pundit,

Thanks for that tip, I'll give bmspares a call. It seems the US cars have the flex joint on the engine pipe, ours have the joint on the manifold itself.... weird difference....

It going to be hell to change it! Thanks again...

GP

[genphreak]

See the pic I took:
I know on other cars I've seen this accomplished with a steel-braided sleeve bit.. I'm sure it could be welded in.

10/10 for a GREAT pic of the situation Mobius! Thank you for posting that, now I can see it clearly. I simply cannot buy a US manifold, they are different to the Euro ones (I think Aus gets mainly euro/UK versions)

My local welding shop reckon a braided sleeve is too hard on that part.. I guess they are being lazy. Given the job they did beforehand I am sure of it

Will report progress shortly...

GP

[genphreak]

i've never had a problem with the flex joint on a 535/735 exhaust, the ones on a m20 525 can break varly easy, i can only guess they abused it getting the system out, i am not sure about the cars over there but on the usa cars head pipe/cat a 735 and 535 will interchange so that may add to the cars you can scavage from

Thanks Winifred, my current engine pipe and converter are from a an Aussie 735ia... you are absolutely right.

GP