So finally the Jag is on the road and driving quite well I might ad. The cats no longer glow red and it is rare if she stumbles or hesitates. But a question.

Does everybody else's stock exhaust ping and pop (or cling and clang) when you turn the car off?

I have a Mazda 3 and Dodge Durango and when I turn them off they are dead silent. But I took the Jag for a spin today and no lie, I could here some of the noises from the exhaust from fifty feet away. As stated, it only makes these noises after driving the car, not during.

 

I have heard it on the X300 sometimes. It is the metal contracting as it cools,

You say that the cats no longer glow red, so the exhaust will possibly be full of unburnt stuff, from the fault that caused the glow, that could give hot spots. A good HARD run to "clean out" the exhaust system will do wonders, and just might stop all those noises.

 

I don't think I can hear mine from 50 feet, but the pinging and popping of the cooling exhaust is definitely pronounced on my car over other cars I've had. I was concerned at first; but I've come to appreciate it as a trait. Cheers! Scott

 

This probably has no bearing on the question, but here is an observation:

Back in the days I installed a high $$$ set of stainless steel reproduction mufflers on my BMW motorcycle.
The stainless items were way noisier than the stockers. Would ping and pop to beat the band while cooling. I just figured it had something to do with the expansion/contraction rate of that particular metal.
Doesn't the Jag have a stainless system?

 

Retro that is a good question.

This Jag was a neglected, destined to the junk yard Jag that I picked up really cheap. It had lots of typical neglect issues (i.e. leads, plugs, CTS, coil, grounds) that I fixed and it runs pretty good now. But at first, my cats glowed very red, one could say a severe fire hazard, and now I wonder if the cat on the right side is ruined. (I feel less pressure in the exhaust with my hand.)

Could it be possible that a clogged cat would increase the amount of pinging and popping and it's intensity?

I guess removing and installing new cats would answer that. Oh, and note, the pinging and the popping doesn't really bother me, just curious as to other Jag owners experience as this goes.

 

If one or both of your cats is plugged up it will deffinatly cause a heat problem,also remember that you have two sets of cats, the ones under the car and another set in the exhaust manifolds. Excisseve heat can cause head warpage and blown head gaskets. To check out this problem, disconect the manifolds from the exhaust and make sure that both headers are flowing equally (if not remedy the problem) if they are flowing well check the cats in the exhaust pipes and fix the problem if one exsists

 

Hey Lumpy, does yours ping and pop?

 

It did until i fixed my cat problem. I chased a lot of other things (fuel pressure,timing,fuel rail which was plugged on #5 and #6,every thing on the intake side) car ran better each time i got everything up to spec,but still had a lack of power and some pinging when hot. Finally found out about the cat problem when the car couldnt pass emision test (was too clean no exhaust getting thru) and i lost the head gasket and warped the head, resurfaced the head and did a valve job on it (make sure if you have to do the head that you keep the buckets and shims in sequence for reassembly). When i fixed the exhaust system i bought the rear set (there the cheap ones) and i gutted the header pipe (pain in the *** but a lot cheaper than new ones) car ran fine and passed emission testing.