glowing cats - err, not fixed (can I borrow some please)

[edhorne]

Evening all

Well I thought I'd fixed it.

Replaced both lambdas and set up on the laptop to within 5% of the adaptives. Had a quick test drive up the road tonight after flushing the cooling system and guess what....

....cats still glowing. Bugger.

Reckon they must be blocked. MOT next week Unless anyone knows any different. I have done a search and it seems a common problem.

So does anyone in the Swindon/M4 corridor have any that I could borrow?

Obviously I'd make it worth your while.

The other option is to buy some new ones. I know they are about £400 each. Has anyone purchased recently from anywhere?

Awaiting your knowledge with anticipation.

Ed

[ducati916]

[quote=edhorne]Evening all

Well I thought I'd fixed it.

Replaced both lambdas and set up on the laptop to within 5% of the adaptives. Had a quick test drive up the road tonight after flushing the cooling system and guess what....

....cats still glowing. Bugger.

Reckon they must be blocked. MOT next week Unless anyone knows any different. I have done a search and it seems a common problem.

So does anyone in the Swindon/M4 corridor have any that I could borrow?

Obviously I'd make it worth your while.

The other option is to buy some new ones. I know they are about £400 each. Has anyone purchased recently from anywhere?

Awaiting your knowledge with anticipation.

Ed
have you checked you ant got a missfre,check the lambas are swicthing ok.by putting a multi meter on the black wire of the lamba and earth the other lead of the multi meter on the engine and check the voltage is swicthing apox 0.01 to 1.80 volts

[edhorne]

Thanks for that.

I haven't checked but on the laptop the lambda values due fluctuate between the values you suggest.

I'll give it a go.

Ed

[GreenV8S]

I've had a car with severely blocked cats, but the time it is bad enough to be noticeable at low rpm the engine simply won't pull at all at higher revs. Yes perhaps you have 'blocked cats' but I doubt this is why the cats are glowing. The heat is almost certainly due to a reaction in the cats. This means you have either a large amount of CO in the exhaust, or more likely unburnt fuel plus oxygen. A misfire will do this very nicely, or perhaps it is just running very rich plus an air leak.

[mudstud]

If it is the cats and you want some new ones try talking to dave at autocraft [phone]. They now do their own version at £130 each. They fitted some to my beast and it passed its emissions with flying colours. Will post the results when I get my P&J back. Having said all that I seem to remember from previous threads that the problem is due to unburnt fuel reaching your cats.

[edhorne]

Mudstud

That sounds very interesting. £130 for a cat. If they get me through the MOT I can hang them up until next year.......

Cheers

Ed

[simonsparrow]

mudstud said:

If it is the cats and you want some new ones try talking to dave at autocraft [phone]. They now do their own version at £130 each. They fitted some to my beast and it passed its emissions with flying colours. Will post the results when I get my P&J back. Having said all that I seem to remember from previous threads that the problem is due to unburnt fuel reaching your cats.

Sounds interesting, are these high-flow types?

[ridds]

Cats don't necessarily get hot due to blockage. First signs will be reduced performance.

Only way your cat's will get really hot is due to retarded ignition combined with too little fuel or WAY too much fuel when the engine reaches rich limit.

If they are blocked to the extent that they are heating up that way DO NOT drive the car as the increased back pressure will do more damage to your top piston land and compression ring. Then you'll have a big ass bill!

Also it will be very odd that you have collapsed both.

Take them off and check. Get a garage to do it. Even Kwik Fit, look up them and as long as you can see through them well (Light through the matrix) then they're ok. Then you know you'll be lookling at other engine issues.

When does this happen?

[GreenV8S]

ridds said:

If they are blocked to the extent that they are heating up that way DO NOT drive the car as the increased back pressure will do more damage to your top piston land and compression ring. Then you'll have a big ass bill!

Is that right? I wouldn't have expected any damage, just more and more exhaust gas reversal and less and less fresh charge going into the cylinder, volumetric efficiency goes through the floor and the engine stops producing power. Mine was virtually air tight, and even with a positive displacement blower producing eye-watering amounts of boost all that happened was the blower stalled and the engine gagged as soon as the throttle was opened.

[edhorne]

Thanks for the comments chaps,

I reckon the glowing cats is down to a misfire which seems to occur after the engine has warmed up. This suggests to me HT leads or coil packs (maybe even the 100 amp fuse?). However it has Magnecor Kv85 leads and had 2 new coil packs last year. I guess it doesn't mean they haven't failed.

The leads run around the back of the engine and through a lead separator each side but then they run next to the water pipe and on top of each other down to each plug. Is this correct? I know its not good for leads to touch each other.

I did have the cats off last week to change the lambda sensors but didn't think to shine a torch through them. I need to do the clutch slave cylinder so they will be off again soon and I will have a proper check.

As for an air leak etc, the adaptive maps are more or less exactly on the 0% line all the way up to 4000rpm so I can't see that too much fuel is going in but I take the point that some of it might not be being burnt.

So its back to the drawing board with a look under the bonnet in the dark to check for arcing and making sure all the HT leads are properly fitted at the coil end.

Thanks for your input. Its a bit demoralising buying a new car and having it go tits-up in the first fortnight of ownership. However having had an S2 and then a Chimaera I guess I knew what I was getting myself into.

Cheers

Ed

[ridds]

GreenV8S said:

ridds said: If they are blocked to the extent that they are heating up that way DO NOT drive the car as the increased back pressure will do more damage to your top piston land and compression ring. Then you'll have a big ass bill! Is that right? I wouldn't have expected any damage, just more and more exhaust gas reversal and less and less fresh charge going into the cylinder, volumetric efficiency goes through the floor and the engine stops producing power. Mine was virtually air tight, and even with a positive displacement blower producing eye-watering amounts of boost all that happened was the blower stalled and the engine gagged as soon as the throttle was opened.

Yep sure will. wrecked a set of rings on an engine on the dyno 2-3 weeks ago. Got away with it just as it was sorted with a new set of rings. Their mechanical properties had all but vanished though, certainly didn't feel like rings anymore.

Pretty sure it will be the misfire issue. Biggest cause of cat temp increase is excess unburnt fuel. However this will not be the only symptom. I would also change your oil as you could be suffering from bore wash and oil dilution from the fuel travelling past the rings.

Saying that, this misfire should show up in the Lambda values when the misfires occur.