Rattling Cat

[TonyD]

Ive develped a nasty rattle in one of my catalytic converters. Obviously the donor Beemer must have dislodged the ceramic honeycombe during the accident which hastened its metamorphosis into a Cobra.

Anyway, is there a method that anyone else has used whereby I can stop the ceramic honeycomb/insert rattling within its casing. The cat is silent when the engine is above idle but when the car is just idling the constant rattle is most disconcerting........not to say embarrassing as it sounds like the death rattle of engine and gearbox on their last legs !!

Cheers,

Tony

[r0lex]

Try taking the box of and shaking out the loose bits:tu

paul

[paul]

Take it to a vet{-}

[TonyD]

Come on guys, there must be someone with an answer ( sensible ones please) out there.

Would a solution be drilling a hole in the box and injecting some fire cement into the space around the honeycomb core, clamping the the casing in a vice and squeezing the case so that it grabs the core, putting a few self tappers through the case into the core etc......

Any suggestions gratefully received.

Cheers,

Tony

[r0lex]

like i said you will have to take out the box and shake the bits out this is not a wind up, or remove the box and put a pipe in its place but you will have to put a new cat in for mot.
the problem you can get is that if the bits in there decide to block up the output for the gasses you could end up with the box blowing off.

Paul

[rocket]

If the cat is "rattling" you need to replace it with a new one.

The cartridge will be damaged and will only get worse.

If it's really going there will be "flaky" particles coming out of the exhaust when you rev the engine, this means that the car would probably fail and emmisions test.

Rgds

Roger

when buying a new one try to get hold of a metal one as these items are welded in and not bonded.They can't come loose. If you give us a ring at Shinybitz I can often do a better deal on cat's than you will find almost anywhere. ( we can get metal cats too) 07720713885:tu

[TonyD]

Hi Guys, thanks for the advice.....

I was hoping to avoid replace the cat for two reasons.......firstly cash....I avoid spending it wherever possible, and secondly I built the underfloor exhaust so that the triangular section original cat fits between the chassis rails and the prop shaft making the underneath of the car as smooth and high as possible for ground clearance issues.

Replacing the rattling cat with another one ( and I have two cats one for each bank of cylinders) will mean cutting and rewelding one side of the the exhaust and shelling out at least £350 for a new BMW cat ( a secondhand one may well have the same problem as the original).

Hence I was loking for a simple, cheap but effective answer.

There are no flakes issueing as yet and the engines breathing hasnt been affected although if the rattling continues this will happen. I went through a hedge backwards in an Omega once and only found out that the inside of the cat was dislodged when the car wouldnt do more than 45mph once it got back from the bodyshop..

Perhaps I should look for a guaranteed BMW cat from a breakers yard or get a new insert put into my casing. Roger are you able to do this and how much?

Cheers,

Tony

[rocket]

I could supply you with the cats they are 9" long and 4" wide (approx)
You can gave ceramic inserts or steel ( with st/st casings)

If you need anymore info or would like us to do the work here or just need supply of the cats to do your self.

Give me a ring on 07720713885

Rgds

Roger

:tu