Fuming Xantia!

tim leech · Post by **tim leech** » 09 Aug 2006, 10:52

My 94 1.8i 8v xantias has failed its MOT on the emmissions being too high also the engine check light comes on (very top right corner of the warning light cluster) sometimes, Ive replaced the lambda probe which didnt help, although the car itself runs perfectly even though its done 130000miles. However if you rev the car hard when on the emmissions tester the emmissions decrease enough to make so it would reach MOT level but as soon as the engine returns to idle they go back up again. Also the engine seems to run warm and the fan cuts in alot when ticking over.

Im having the cooling system and engine oil flushed and refilled as a precaution, Im told it could be the catalyst thats shot, although you can smell it when you work the engine hard, Im loated to spend £100+ for a new cat to find its not that at fault. Ive been told it could be the charcoal filter aswell or possibly a blocked breather? The cars just had new plugs and filters also.

Im not mechnically minded but any advice would help! As ususal the local Citroen dealer havent a clue and want to charge me £70 just to look at it!

Many Thanks

Confused of Derby!

AndersDK · Post by **AndersDK** » 09 Aug 2006, 10:59

What emissions ?
HC ?
CO ?

With all new filters, plugs and oil - there is no reason to flush/renew the oils & filters once more. Waste of money.

Clearly the engine is sort of rich running idle - as the emissions gets better on higher revs.
That points to the CTS which exactly is responsible for the "choke" function.

tim leech · Post by **tim leech** » 09 Aug 2006, 11:03

Its the HC thats too high, i havent changed the fluids as yet just doing that now as they need doing anyway. You thinking it could be a choke thats sticking, even though its fuel injection and would that make the engine check light come on? And can you adjust them the same as a carburettor?

Many Thanks

slim123 · Post by **slim123** » 09 Aug 2006, 13:26

Get yourself down to your nearest motor factors and buy a couple of bottles of injector / fuel system cleaner, let the tank run fairly low, then pop them into the tank, take the car for a good warm up thrash and return it to the MOT, you will be suprised at the difference in the readings.

I have done this loads of times in the past, when people have been quoted for new sensors, catalysts and all sorts, it normally works!!

Regards
Slim

tim leech · Post by **tim leech** » 09 Aug 2006, 13:56

Already done it matey but its worth a nother go I expect thanks!

_kid_ · Post by **_kid_** » 09 Aug 2006, 14:26

from the bob mckay website

3. if the vehicle fails for high HC then ...if the CO passes, the vehicle is probably misfiring. Or if the CO fails and the Lambda reading is too low, the mixture is probably too rich and it may also be misfiring.

Was the lambda sensor a good quality one? Some universal ones are notoriously unreliable. what is the readings from the emissions test?

As suggested it could be the CTS assuming your car has one, my 1996 16v it is green colored, near the thermostat housing, it may be worth changing this. unipart/ partco sell them for around £13.

Further reading

http://www.bobmckay.co.uk/p_emissions.html

tim leech · Post by **tim leech** » 09 Aug 2006, 17:27

STOP PRESS!

It turns out that one of the pipes into the heater matrix is split and loosing water, so the radiator is ok, the cats coming off tomorrow to be inspected but it looks like its the original which is 12 year sold and done 130k!

tim leech · Post by **tim leech** » 09 Aug 2006, 17:29

My cars a 94 8v unit so im unsure if it has one, it may be the injection systems out of tune aswell so that will get looked at.

citronut · Post by **citronut** » 09 Aug 2006, 17:43

i think its bourder line whether your car has to have the full emmisions test or if it can get away with the short one,and if it can just go through a short test when the MOT tester holds the revs up and emmisions come within the limits then he is suposed to give you a pass,also if it HC is to high usualy its either ignition fault or running to leen,sound like its to leen to me
regards malcolm

Post by **philhoward** » 09 Aug 2006, 20:08

I thought ALL Xantias had Cats, so no escape from an emmissions test on the premise that if it had one from the factory, it must meet the Cat requirements..

HC's too high on a Catalyst test might be fine for a pre-93 (or is it 92?) car..if it's less than about 2-300ppm, then i'd suspect the Cat, especially if you can smell it. That would be a normal figure for a non-Cat vehicle.

AndersDK · Post by **AndersDK** » 09 Aug 2006, 23:51

High emissions on HC contents is usually a pointer to engine oil taking part of the combustion ...

This in turn points to the valvestem seals.

What viscosity grade engine oil are you using ? The '94 Xantia is factory spec'ed to 10W40 or 15W40 viscosity grade oils.
A lower viscosity oil may very well cause a problem on HC emissions ...

tim leech · Post by **tim leech** » 10 Aug 2006, 11:11

Catalyst is buggered its confirmed, ordered a new on today at a cost of £100! ouch! Hoepfully with thsi done an dthe heater pipe mended it should be roadworthy again after 7 months!

citronut · Post by **citronut** » 10 Aug 2006, 18:43

mind you dont put any exhaust paste in the front joint as this can damage you cat if it goes inside
regards malcolm

dnsey · Post by **dnsey** » 10 Aug 2006, 18:50

It's a bit of a "chicken and egg" situation - are the emissions high because the cat's had it, or was the cat wrecked by excessive emissions?
If there's any hint that the HCs are still high after the new cat's fitted, I would avoid running it until the problem's solved, or you may be in for another new cat much sooner than you expect

tim leech · Post by **tim leech** » 10 Aug 2006, 23:07

The cat rattles like its full of broken glass so you can safetly say its had it! Will put it on the gas tester as soon as its on and see what happens!

If there still way up thenits back to the drawing board!