21 replies to this topic

[Carvell]

Ok so the problems have returned. So back the AB but again they found nothing. Symptoms are that the car judders. It's not a judder that you wouldn't notice, its a full on throws you back and forth in the seat. The best way I can describe it is imagine that your driving along at 70mph and someone is quickly pinching and releasing a fuel pipe so the revs drop and instantly spring back up making the engine lurch. As said before it causes the engine to lurch that much that the cat is now ratting. So what's the next step? Really don't want to start randomly replacing stuff as its an intermittent problem. Any other garages north west area who I could give it too?
Thanks

[Ipod]

The CAT should not rattle...the innerds sounds like they have collapsed and broken.

mine did this, and had simler symptoms..aslo felt like it was loosong power.

I removed cat and found large bits of it in the rear box, banged them out and put new CAT on and all was good.

[Fast Ivan]

certainly sounds like a fuelling issue, are the plugs still sooty?
When the garage carried out the diagnostics did they check that the sensors are operating within the required parameters? I say this because its one thing to plug it in and clear faults and another thing entirely to check that the sensors are within the required ranges. sensors can be showing no faults but may not be working correctly, the diagnostics may not show this as a fault, they would need to be reading and interpreting the live data.
As a first step I would check that all the sensors are clean and that the loom and connectors to the sensors are sound, include removing and cleaning the idle air control valve

EDIT: are you sure its not the heat shield that's rattling?

Edited by Rob Mac, 10 April 2013 - 07:26 PM.

[Carvell]

Thanks for the replies

iPod - the car had the issues before the cat started to rattle. I'm a bit hesitant to replace the cat only to find that the car continues to stutter and therefore the new cat gets ruined too. How could the cat make the car judder?

Rob mac - I will follow that up, I'm not 100% sure what the garage did. They are well recommended so I'm sure they will have checked each sensor rather than just cleared the faults but the first visit was a while ago and therefore I can't remember.

Also, spoke to my Dad who is driving the car at the moment he said the other day the revs stuck at 2000rpm he was able to drive at 30mph without touching the accelerator. When he go back to the house with is a good 15 minutes drive he turned the ignition off and restarted and it was back to normal. Might be linked or just another issue?

Thanks

[Fast Ivan]

Also, spoke to my Dad who is driving the car at the moment he said the other day the revs stuck at 2000rpm he was able to drive at 30mph without touching the accelerator. When he go back to the house with is a good 15 minutes drive he turned the ignition off and restarted and it was back to normal. Might be linked or just another issue?

Thanks

they may well be linked

[Ipod]

A broken inner gubbins of the cat will result in the exhaust gasses not being emmited smoothly and in my case partialy blocked, by huge bits of debris being blown into the rear silencer, and will cause juddry/lumpy running and even huge loss of power!

You dont have to buy a new CAT to test it, just bang it with ya fist (when its cold) and see if you can hear it rattle, or take it off (only 4 bolts) and give it a shake, and if you have an iar line, a gentle blow out (in the direction of the exhaust flow

[Ipod]

A broken inner gubbins of the cat will result in the exhaust gasses not being emmited smoothly and in my case partialy blocked, by huge bits of debris being blown into the rear silencer, and will cause juddry/lumpy running and even huge loss of power!

You dont have to buy a new CAT to test it, just bang it with ya fist (when its cold) and see if you can hear it rattle, or take it off (only 4 bolts) and give it a shake, and if you have an iar line, a gentle blow out (in the direction of the exhaust flow

EDIT: If the revs are holding up, it could aslo be the TP sensor having a spazz (might have been having an ok moment when tested)

Not having read back, but have you cleaned ALL sensor connectors with electrical contact cleaner?
I do this about every 2 months, just out of precaution, and good engine managment