Tinkling exhaust

[cockers]

My 106 is due for its MOT at the end of this month and, after nearly three faultless years, it's decided to throw a surprise at me.

There's a strange "tinkling" noise coming from the exhaust between the downpipe and the cat - at first I thought it was something hanging off the car, because it almost sounds like someone dragging a set of keys along the ground, but it actually seems to be inside the pipe.

Does anyone have any ideas what it might be? I have a bad feeling that something inside the cat has shattered and that I'll need a new one.

I expect I'll find out what it is at the MOT anyway, but I'd like to sound reasonably intelligent when I phone the garage, 'cause otherwise they'll see me as a cash cow.

Cheers,

Paul.

PS - It's just pissed it down here at work and I'm feeling very smug because I sprayed water repellant all over the Chimaera's hood last night.

[mondeoman]

Could be the cat, but so what?? Just wait til you get the results of the emissions tests before you shell out on a new one - just because it may be cracked doesn't mean it'll stop working.

[CarZee]

bits of exhaust valve ?

[elanturbo]

maybe the ceramic honeycombe in the cat is breaking up?

[jeremyc]

When do you hear the sound - when moving, stationary, engine running/off?

Could it be the engine pinking, or the excess fuel igniting in the exhaust to produce those flames out the back?

[smeagol]

I would say bit of cat, but as Elanturbo has said get its emmisions checked before ditching. A very small piece may sound like a lot in effectively a metal drum. Eg a bit of gravel on the Elise chasis sounds like a nut coming off

[Simonelite501]

I've had exactly the same problem, and my Lotus doen't have a cat. Everyone that I talked to said that if it did have a cat, they would assume that the internals of the cat were disintergrating, so my best guess would be that. The cause of the tinkling in my exhaust was pieces of grey/black lavaish lumps about the size of boiled sweets. No idea where they came from, took the system to bits, shook it out, et voila! no more problem. I suggest that you do the same. Good luck.

[Mojocvh]

Cat breaking up, had this 3, yes 3 times on a previous car.............MoJo

[cockers]

quote:
Could be the cat, but so what?? Just wait til you get the results of the emissions tests before you shell out on a new one - just because it may be cracked doesn't mean it'll stop working.

Cheers Mondeoman and others. This sounds like an eminently reasonable suggestion! No point volunteering to shell out the hard-earned, is there?!

[Richard92c2]

quote:
Could be the cat, but so what?? Just wait til you get the results of the emissions tests before you shell out on a new one - just because it may be cracked doesn't mean it'll stop working.

If I had a cat "tinkling" in my car I'd stuff his as* into the exhaust pi....... Oh, its already there?

Ok. I know the drill!

[456mgt]

Isn't there an additive- I think it's called 'CAT guard' - you can put in your fuel that guarantees the car will get through the emissions test? I remember buying some from Halfords a couple of years ago. If it is your cat disintegrating, it may need a little help.

[cockers]

Well, it passed its MOT!

Mondeoman - Thanks for the advice about keeping my trap shut. Discretion is the better part, an' all that.

Simonelite501 - I'll have a shake at the weekend!

Cheers all,

Paul