Just wondering if anyone has had a catalytic converter failure on an XK8. Unfortunately after someone ran into the back of my car it hasn't been starting properly and the diagnosis shows a fault report on one cat with a possible cause for it being "fracture" which could fit with a rear end shunt knocking the exhaust and the shock fracturing the cat. I am struggling to convince my insurance company that this is accident related, even though it was starting perfectly pre-accident but doesn't now. The latest is that they say cats have a life of 10 years and my car is 10 years old so just one of those things.

I'm kind of hoping that I don't get lots of people saying their cats have failed but some idea of how common it is on the XK would be good. My other car is 14 years old with 186k miles showing and is still on the original cat with no sign of problems so they don't all fail at 10 years!!

 

They do rot through but not what I would say common, then again I would be surprised if the shock from the back effected the cat unless it was very rotten, the pipe going through the rear cage/axle would of folded up first?

 

The diagnostic check which showed the problem says possible causes as melting or fracture, it seems unlikely (but not impossible) that one cat would melt and the other not which indicates fracture as the cause to me. Given the angle the cats are at and how fragile they apparently can be it could be that a knock at the back would send a shock through the pipe until the point where it was no longer rubber mounted which is the cat. The trouble is the only way to find out if it is a fracture would be to take it off and cut it up I guess.

If there are very few which have needed replacement it hopefully strengthens my argument that it was the accident rather than general wear and tear. On the basis the car never hesitated to start before the bump but hasn't been starting properly since it would be quite a coincidence for it to have failed at the same moment the accident happened.

 

Here's a couple of pics which shows the typical place they go, this is normally at the bottom where the mounting bracket bolt on, water/condensation settling in the bottom of the cat rots them out, they are made from cast steel with a steel wrap which the straws sit in

 

Here's the LH Cat from my 2000 XJ8L when it failed in August 2006 at 80K miles.



Although it looks dreadful (and the RH was the same) for only six years old, they didn't rust through before failing internally. There was no impact involved. No doubt your insurers will be able to cite many similar failures.

My solution was to source a replacement pair from a specialist Jaguar breaker about seventy miles north of you. Incidentally these came off an accident damaged car which had heavy side impact and worked perfectly when I sold the car with another 5K miles on it.

I sympathise with your predicament but you're going to have a hard battle to overturn your insurers on this. A Consulting Engineer's report could swing it but end up costing you more.

Graham

 

Thanks for the replies, I haven't got underneath the car to look at the cats but there is no noise from them and the car runs perfectly once it starts, the only time the problem shows is when starting with it turning over for a while and then starting reluctantly but a little throttle then gets it running properly.

GGG - what were the symptoms of yours failing internally?

My battle with the insurers is that they say it is just wear and tear and have sent an "independent engineer" to look at the car, his verdict was that the impact on the rear was only light and therefore the cat damage is most likely wear and tear. I have asked for an explanation of how the wear and tear suddenly took place at the time the car was hit from the rear and have had no response so far. I have also asked how come the wear and tear has only affected one cat rather than both on the basis the engineer said that it often occurs due to a car being mis-fuelled at some point, he couldn't explain how it could be mis-fuelled in one half of the engine and not the other.

The insurers are saying that I can get an engineers report myself so I have queried what would constitute a suitable engineer and they have said a Jaguar dealership. On that basis I am hoping Jaguar would rather the perception is that cats fail because of impact rather than wear and tear. I'll let you know!

As a final point, if all else fails I may need contact details for the Jag breaker 70 miles north of me

 

Other than a slight difficulty in starting which I'd initially thought was a dirty TB, the first indication was failing the MoT! The emissions were through the roof:




We went through everything - MAF, TB, H2O2 Sensors and even swapped the ECU not believing Cats could fail at that age.

All the time it was running perfectly but it took a change of Cats to get the emissions back in range.

Graham

 

I still have my old cats after the Nameless install. If you still haven't resolved the issue and don't want to spend the big bucks for cats from Jag or Nameless I could be persuaded to get rid of these.

 

Thanks for the offer - not sure if XKR cats are the same as those on the XK8 but probably more of a problem is that you are in NY and I'm in the UK, shipping costs and risk of damage in transit would probably make it less than worthwhile.

 

I didn't notice your location. You're probably right, shipping would likely be prohibitive.

 

Update to this - I finally got a cheque from my insurance company to cover the cost of the cat and fitting. It took 5 months and quite a lot of effort but I got there in the end. Thanks for the help here, being able to say how few people seem to have had failures was part of my case. In the end the insurers said they couldn't prove it either way but would accept the cost.

After all the hassle I will definitely be looking for a different insurer next year!