Diesel catalytic converters

mikeg · Unread post by **mikeg** » 23 May 2004, 12:47

This might seem a simple question, but do any of you experts know the life expecancy of catalytic converters. I have a 1997, fully serviced, Xantia 1.9td estate which has done 126000 miles. What should I expect? Also, what would determine its demise.

NiSk · Unread post by **NiSk** » 23 May 2004, 13:02

Diesel catalysers last forever (or until they rust away) - they work on a totally different principle to thier petrol engined relatives. My own XM TD12 has covered over 500,000 km and the cat is still working like new.
//NiSk

mikeg · Unread post by **mikeg** » 23 May 2004, 13:19

Thanks NiSk, thats very reassuring.
Mike.

amcc · Unread post by **amcc** » 23 May 2004, 14:11

I was told by a mechanic that my diesel xantia would run as well without the cat. what do you think

Stuart McB · Unread post by **Stuart McB** » 23 May 2004, 15:43

Never had one my self but our staff / plain cars have them. Mainly Renaults & Peugeot thought. Talking to one of the guys at our Park lane depot (some may know what that is) garage they said that the cat on a diesel will last for ever or untill you take the vehicle off road a little and hit a tree stump or simalr.

paranoid · Unread post by **paranoid** » 23 May 2004, 16:41

Is that the Park Lane with the very fast Ice cream vans with the disco light on the top[:D][:D].
I am just down the road about 2 minutes from Spaghetti, Sorry to hear about your Colleage on Friday, knew it was bad by the amount of cars, helicopter etc.

Stuart McB · Unread post by **Stuart McB** » 23 May 2004, 20:22

You known the place well then. If you ever get the chance have a look at some of the write off's there. You'd never buy one of our used cars.
Cheers for the sympathys.

NiSk · Unread post by **NiSk** » 23 May 2004, 20:29

To Allan - (amcc) yes, your Xantia will run just as well without the cat, but the world would be a dirtier place without it . . . so why remove it? Diesels have been accused of filling the air with pollutants and a cat is one way of reducing the emissions - and since it doesn't steal any power from your engine why not improve your conscience and let it be . .
//NiSk

Kowalski · Unread post by **Kowalski** » 24 May 2004, 14:59

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by NiSk</i>

and since it doesn't steal any power from your engine why not improve your conscience and let it be . .
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
I've just replaced my catalyst equipped exhaust with a non-cat pipe since it had rusted through, was beyond repair and a new cat-pipe would cost £100 more than a non-cat pipe.
Performance now is much better, especially below 2000rpm i.e. before the turbo is able to provide full boost, this points to the catalyst being partially blocked or in the very least, very restrictive.
If the catalyst was partially blocked, I can't see it doing its job very well at all. Once a catalyst becomes coated with soot, so that oxygen can't get at the catalyst surface, the catalyst doesn't work at all.
I don't have fuel economy figures as yet but when I do, I will publish them here.

NiSk · Unread post by **NiSk** » 24 May 2004, 20:56

That's why diesels need a good blast every now and then - to clean the soot out!
//NiSk

James.UK · Unread post by **James.UK** » 24 May 2004, 22:32

I hear that cats hate water? my mate had two cats break up when he forded a stream in Scotland on two consec holidays-years.... so beware! lol..

Richard Gallagher · Unread post by **Richard Gallagher** » 25 May 2004, 02:39

James is quite correct because cats are mainly a large piece of china so they, just like dinner plates don't take too well when very hot to being placed in cold water.
Some newer cats are made out of metal so will be more durable. But enter a ford at you peril, car and water!!

Kowalski · Unread post by **Kowalski** » 25 May 2004, 14:26

My diesel gets up to 4000rpm several times a week (sometimes up to 4500) it is driven at 70mph 350 miles per week (10 35 mile journeys on dual carriageway), and still the catalyst was blocked.
Do you think more thrashing would give my car any benefit?

tomsheppard · Unread post by **tomsheppard** » 25 May 2004, 18:02

The catastrophic perverter was a knee-jerk reaction to misguided and ignorant tree huggers by a panicked Government. They don't emit oxides of lead which can be excreted but oxides of Rhodium, palladium and platinum, at least two of which are very toxic. The hydrogen sulphide they produce combines readily with rain to form sulphuric acid and they use about 9% more fuel, producing 9% more CO2.
Diesel cats are almost certainly just as bad. Only morons would specify such a stupid thing to be fitted and if it is legal to remove it then you'll be doing the planet a favour.

Unread post by **philhoward** » 25 May 2004, 23:58

More a point with petrol ones (but whilst we're on the stupid legislation bandwagon)...
When CATs first came out (10-odd years ago), it was stated that they took 8 miles normal driving to get to fully operational temperature; up to this point they actually produced more harmful (although different) emissions than non-CAT cars of the time. The average journey distance 10-ish years ago was...9 miles. Foot, Shoot, Yourself, in the.......