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MG MGF Technical - What will cook?

walking to tescos I saw a cat heatsheild on the ground - and the F has stopped rattleing :-o. So assuming the worst - what is there to cook back there?
Will Munns

I was under the impression the heat shield on the cat was to protect it from thermal shock .... More heat will radiate from the downpipe/flexi joint !

If I am right ( and I may not ) it is not shilding the engine but itself!!!!
C Bowes

I have run with out the CAT heatsheild for a while now. No issues yet
Steve Ratledge

Hi All,
heatshields in general on cat's are to protect other items from the cat, like dry grass, and other flammable material, if you ever get the chance to see a cat glowing red due to a misfire in your engine you'll realise why.
Mike
Mike (London Office)

Hense why its on the leading face only!
Steve Ratledge

Will,

Have to agree with Mike, brother had an old 220GTI with a rattle from the exhaust, took it to kwik fit, they prised the heatsheild off and told him that it was rattling because the fixings had rsuted and that he didn't really need it and he had no problems with it after that. Had the same thing with mine on a rover coupe but got the tf before doing anything about it, as mark puts it, its in case it sets long grass etc aligght after you have parked the car.

john
J Ip

Dont think there's anything "meltable" nearby. Certainly no rubber hoses, bushes etc.

Would a CAT run a lot hotter than a CRP. After all it has no heat shield.
Bob Millar

I'd imagine that a cat would get a lot hotter than a CRP Bob. Firstly, it is designed to run hot - it requires heat to catalyse the oxidation of CO and NOxs etc. Secondly, it has a much larger surface area exposed to the exhaust gases, thanks to that honey combe structure - the CRP, in contrast, is just an empty pipe. Result - much more heat transfer. And finally, the metals used to catalyse the exhaust gases probably have a much higher heat conductivity than plain old stainless or mild steel...

Bottom line: I doubt that a CRP would need a heat shield any more than any other section of the exhaust pipe. :o)
Rob Bell

Yep the CAT is a second stage burning device to clean up the emisions - it gets a lot hotter than the manifold!

But reassured now - will just get on with changing the oil and filters.
Will Munns

I used to live in New Jersey and each fall (autumn) there would be warnings about parking cars among fallen leaves. Apparently they lose a few each year to leaf fires caused by hot cats.
Brian

> Firstly, it is designed to run hot

Ah probably an exothermic chemical reaction taking place in it as well!

And my chemistry teacher said I learned nothing!!!
Bob

This thread was discussed between 06/09/2004 and 08/09/2004

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