E91 335i - Cat to rear section gasket

[Gad-Westy]

Hi all. To replace the prop bearing and coupling, I removed the exhaust from my 06 335i Touring. Managed to only break one stud!

Anyway, as I removed it the gaskets fell out and I was surprised to find circular rings as well as the regular diamond shaped gaskets. Real OEM suggests the rings shouldn't be there and there is no obvious seat on the exhaust where they would sit.

I think it is these. It looks like they may be intended for use further up the system but thought I better ask before I leave them out.

[Gad-Westy]

Hmmm, well I obviously got something wrong as the exhaust is leaking from that joint. Any ideas before I take it somewhere else to sort?

[Ian Geary]

I realise this is a few weeks on now and you've probably sorted it, but

I too removed my cat to rear exhaust, and had a ring fall out.

I think the oe gasket is constructed with an inner ring and an outer diamond shaped gasket fixed together. So only one part on realoem.

Over time they come apart, leading to them separating when removed. It might explain why the gaskets are so expensive... though that's par for the course I guess.

I just refitted the outer diamond shape part, but luckily didn't get a leak

(Although I used an electric impact gun to tighten up as there's not the space to get decent torque with just a extension bar imo)

Hth

Ian