Just dropped off.....

Rivendell · Post by **Rivendell** » 08 Jul 2004, 00:35

Hi ...
I noticed a rattling noise yesterday whilst negotiating some speed bumps. Something was trailing from under the car, but before I could stop and look, it just dropped off and lay there in the road. It's about 8" long and curved as if it may be a heat deflecting plate or something. Not much to go on and the Haynes manual is next to useless on this occasion, but anyone got any ideas..?
Cheers,
Phil

Robin · Post by **Robin** » 08 Jul 2004, 00:55

Phil, it could be a heat deflector shield from above the catalytic unit on the exhaust. That is the first box on the system from the engine. If no cat same possibility from other exhaust area. R

Rivendell · Post by **Rivendell** » 08 Jul 2004, 01:29

Cheers Robin. Assuming it's the heat deflector from above the cat, how important is it and how easy is it to put back into postion ?
Cheers

Post by **philhoward** » 08 Jul 2004, 01:52

If it fell of, it can't be that difficult...assuming the fixings can be reused!
It protects bits above it (pipework normally) from the heat of the Cat; depends what's above the cat, really! I have heard horror stories of carpets melting, but I think that MAY be folklore...

jeremy · Post by **jeremy** » 08 Jul 2004, 03:36

Catalysts can get very hot - I seem to remember warnings about parking hot Jaguars in combustible materials like straw or grass.
jeremy

DLM · Post by **DLM** » 08 Jul 2004, 03:43

I thinks that goes for all kinds of cats - not just the big cats.....

paranoid · Post by **paranoid** » 08 Jul 2004, 12:20

Unfortunately it's not a myth, mine rotted off my rover unnoticed, heat going through the tunnel dried out all gear change linkages, and made console around h/brake and gear lever go a very funny shape, Very Very hot in the summer as well, Only took a hour to make a new one out of steel plate bent to shape. Is it me being daft or do they stay hot for a long time?

John F · Post by **John F** » 08 Jul 2004, 17:34

My understanding from visting an exhaust manufacturer is that the platinum in the catalytic converter is, as it says, a catalist in chemical reaction with the gases, and as a result of this reaction gets hot; hotter than the exhaust gasses which in fact act as "coolant" to the reaction. Once the engine is switched off there is nothing to "cool" the cat and it gets very hot, hence the heat shields/deflectors, etc. In fact, the cat is a self destruct entity. I don't think not replacing is an option; insurance companies don't like burn-outs and delve deep, even with third party, fire & theft.
Pity they didn't tell me about the particulates but then again I didn't ask.

John F · Post by **John F** » 08 Jul 2004, 17:37

Or there again, with safety in mind, decatting may be an option[:D]

Robin · Post by **Robin** » 09 Jul 2004, 01:36

Phil, if it is the cat deflector then it needs replacing somehow. Too many cables, linkages etc above it. Try to wire it back on directly to the cat with a spacer of some sort between the two as a temporary measure, you need a good 30mm minimum between the cat and deflector plate. This is to allow air to flow over of it. Yes, cats very bl**dy hot so don't go under there until it has cooled off. R

Rivendell · Post by **Rivendell** » 09 Jul 2004, 05:29

The plate seemed to originate from about the same position as the gear lever. Not sure what part of the exhaust system is in that vacinity, but maybe a trip to my local kwikfit might be in order. At least I can get a look underneath that way.
Cheers
Phil

Rivendell · Post by **Rivendell** » 09 Jul 2004, 05:31

Correct me if I'm wrong, but I don't think I can de-cat a 1994 2.0 LX petrol Xantia..........can I ?

Kowalski · Post by **Kowalski** » 09 Jul 2004, 14:22

All petrols since about 1993 need catalysts for the MOT emissions.

np · Post by np » 18 Jul 2004, 02:48

Found out what it was,where it was from Rivendell??

Rivendell · Post by **Rivendell** » 18 Jul 2004, 17:29

Sorry guys [:I]
I visited my local kwikfit and they stuck the car up on the ramps. Checked underneath and the heat shield is from the underside of the cat. Apparently they're only spot welded into place and frequently drop off anyways. According to 'Mr Kwikfit', cats rarely get hot enough to ignite any grass they're parked over, unless the car has been driven hard for some time beforehand.
Anyways, I didn't bother getting it put back on, but will be aware of where I park the car after it's been running for any great length of time.
I did discover that there doesn't appear to be any signs of corrosion on the under side of the car and the whole exhaust system appears to be in good condition [:)]
Thanks for all your guidance and info guys. It's nice to know I have such a vast amount of experience and knowledge available when required.
Cheers
Phil