cat on its way out.......

[paulmb]

I think my cat is on its way out......when i start up the car, something starts to rattle underneath.

Had a look yesterday. The rattling seemed to be coming from the exhaust, just as it comes down from the manifold and bends towards the cat. I pushed this section of the exhaust up with the end of a screwdriver and the rattle stopped. If i let go it comes back.....i don't think it is the cat but i'm not sure.

It may be the heat shield......if it is the cat, where is the best place to get one?

paul

 

[stargazerplus]

Are you sure it isn't just the heatshield? These corrode and rattle - if you can stop the rattle with a screwdriver, this is probably the cause. Cats CAN rattle but do not necessarily cause an emissions failure. Cure? A large jubilee type hose clip tightened around where you pressed the screwdriver will cure it. Couple of quid in B & Q

 

[paulmb]

going to jack it up and have a good look at it tonight.....hope its not the cat?!?!?!?!?!?!?!

 

[pluggers]

Id start by ripping the heat sheild off first,I had to do this on my old c class as it was rattling badly a bit of brute force with the screwdriver saw it off in less than 2 mins..As cats can be very expensive.

 

[paulmb]

so its ok to take off the heatshield.........once ripped off, it won't go back...is this right?.....i suppose that will tell me if it is the cat or the heat shield.

thanks

 

[pluggers]

once ripped off, it won't go back...is this right?

thanks

Correct. What your doing is like helping the rust on its way by ripping off what the rust hasnt managed to corrode yet.

 

[paulmb]

thanks mate, i'll try that tonight.

 

[chorcheela]

I've just been thru exactly the same thing in the last few weeks. The exhaust started to rattle about Feb time. I thought nothing of it, as it didn't affect the driving at all. Then over the last month or so, it got worse, and then the car started to lose power. I couldn't work it out. I was on the A14 over taking a truck (which was rather keen to pull out into my lane) and the car wouldn't go over 65 mph. It panicked me a bit!! I cruised home and just about made it - the car was by this time struggling to do 50 mph....

The monolith, which is the cotton wool-like structure inside the cat, had broken down and apparently this then starts to block the exhaust flow from the engine - hence the power loss.

The answer? A choice between an MB cat (£1000 ish), or a 3rd party (£245 fitted) - I went for the latter and all is ok.

I am surprised at a cat failiure on a 7 year old car with 127000 miles (almost all motorway miles).

The normal triggers for a cat failiure are bump starting or engine misfires where unburnt fuel gets into the cat, but neither of these happened with mine.

My advice, get it fixed before you end up with a story like mine!

 

[rajinder_1]

hi chorcheela wer did you end up buying your cat from? i know what you mean about paying the MB price, i have got aftermaket cats for my SL as i could not justify paying nearly double for the cats, although i have heard many horror storries about aftermarket cats!!!!
how are yours, not causing any trouble or too much noise are they?

Raj

 

[chorcheela]

Rajinder,
The cat seems fine; it is more noisy under heavy acceleration (the 2 litre in an e class never sounds good under heavy accelleration!) - fairly noisy - but other than that fine.

I got it fitted by a local exhaust place in Bury St Edmunds (Hardwick Tyre & Exhaust).

It's been on for 3 weeks now so hopefully this one will last......