Can anyone help with this? I recently had cause to change an ignition coil on my 2006 xj VDP and I made a decision to change all of them as the car has got 180k miles on it. Over the last 1-2 years I have become aware of the fact that the exhuast note was getting more throaty at lower RPMs than previously. In the past it sounded quite loud when I was in sports mode and put my foot down hard at around 4000 rpm but over the past couple of years it seemed to be louder at around 2000rpm to the point that I sought the opinions from two seperate shops as I thought I had a leak in the exhaust but none could be found.
Now, after fitting 8 new coils, it is like driving a different car. The exhaust noise is back to where it used to be, the engine feels smoother and the performance just feels better.
My question is this, why would fitting new coils affect the exhaust noise?
Thanks for any comments.

 

I don't know if a worn catalytic converter would do that?

 

A spark is a spark ..it either ignites the fuel or it does not . talk of fat sparks etc is rubbish so I think you need to look elsewhere .
You are also asking the question on the wrong part of the forum ..this is for the XK8 XKR.
But welcome and I am sure you will have an answer.

 

If I’m reading the OP correctly there is no problem, just a fishing expedition for an explanation for the current happiness being experienced.

Just be happy and let the mysteries of the universe remain unknown.


Z

 

I would suggest that the exhaust is slowly burning out and getting louder, hence the gradual increase. It IS a 16 year old car with 180K after all.
Why the increase after the coils?? Maybe because it's burning complete now and more combustion is MORE POWER!!! Just a thought. TM