Hey Guys,

I've recently noticed a knocking noise coming from the car, it almost sounds like plastic hitting plastic. The noise doesnt go away when I press the gas, and the rate of the knocking doesnt increase or decrease with the speed of the engine. I've narrowed it down to the transmission area, and its easier to hear from the inside then from the outside. It only happens when its cold out, probably when its below about 45 degrees. Also, it only happens after the engine has fully warmed up. I cant figure out what this might be? Does anyone know what it might be?

Thanks in advance,

Mat

 

Just an update:

I brought the car in to the dealer and had them take a look at it, the noise had stopped because it was warmer then usual today but they got it up on the lift and found that both front airshocks are mal-functioning and need to be replaced! Good news is that everything is covered under the extended warranty that I purchased a few months ago, just before one of the compressors failed.

Mat

 

Another update,

I just got off the phone with my dealer, and they couldnt reproduce the noise for the extended warranty company, so they are denying the claim! They assured me that as soon as it starts making the noise again they will get the warranty company back to hear it.

Mat

 

The air shocks don't have to make a noise to malfunction. If the dealer says they were bad, then the warranty company should honor their warranty.

 

I just got home from the dealer with the car, I was told that the suspension was recalibrated and that might take care of the problem. Well.......... I got about 15 min away from the dealer and the noise starts up again! Although not as loud as it used to be, I can deal with this. As soon as it gets bad again though im taking it right back!

Mat

 

You shouldn't have to deal with any noise on that car. Take it back.

 

unfortunatly extended warranty companies are a bear to deal with..they dont approve for noises, only failure. Its tough and trust me, nothing like diagnosiing a problem only to have an ext warr co. deny claim, or approve but only for RNR no diag time...WTF you think we diag by touching a car??????

 

Well I think im going to take in the car next week, the noise is much louder then it was before and it really gets annoying when your sitting at a traffic light. Its even loud enough where I can hear when I take my foot off the gas while cruising on the highway. Thnaks for the advice!

Mat

 

Let us know what it was.

 

I am having a hard time imagining how the air shocks could make this noise and it would sound louder inside the car than outside and only when the car is warmed up. There is a disconnect here. Did the dealer tell you any details of the failure mode? I am usually suspicious when two parts like this fail at the same time and they are expensive parts! My first reaction is that this is not the problem. I'll think about it some but be careful.

 

Mat,
Mine does the exact same thing... Just picked up a 2004 XJ8 with 40,000 miles. If you turn off radio, and climate control you can hear the ticking very well. Notice that it is not engine rpm related! Although if I rev the motor above 2K then let it come back to idle it will go away for a short while then come back on. Today I brought the car to the office heated garage and let it sit and idle to try and isolate the location.

Open the hood and take off the plastic cover above the brake reservoir (driver side up near the firewall) see if you will hear the ticking louder from that location... I do.

It actually will seem to cycle on and off sometimes. Sounds like plastic on plastic, like a fan blade hitting a shroud. Maybe half a dozen times per second. It is louder in the cabin than in the engine bay, unless you remove the cover as mentioned above.

Keep us posted!

Tom

 

Panels,

Mine sounds exactly the same as yours, and does the exact same thing when I rev it above 2k! My car is about to hit 40k as well. Im going to try to bring it in on monday or tuesday to the dealer, and see what they say this time. They cant deny its making a noise now, because its doing it when its warmer out and the noise has been getting progressively louder.

Brutal,

I was talking with one of the mechanics and he was also saying how the warranty companies are a horror to deal with. He told me that one of the companies would send out transmission from junked cars, or cars in junk yards and force them to install it, even if the technician thought it was in bad shape. They would install the transmission and the car would come back not long later with a bad transmission again! He also said that the inspector from the warranty company that was looking at my car was very hard to deal with, he was checking so many things that was not related to my problem just to make sure I had not modified anything or that anything wasn't within original Jaguar spec. Im guessing that they do that just to try to squeeze themselves out of not having to pay for the work.

Thanks everybody!

Mat

 

Matt did you get this resolved? Very anxious to know what the issue was...
Tom

 

Sounds like a fuel pump, but you should not be able to hear it from that location. Strange!

 

I've had the flu for the past week, so I havent had time to bring it in. I am worried though that the sound is so intermittent now that when I bring the car in i'll just get the same story from the service techs that they couldn't reproduce the noise for the warranty guy again. I plan on bringing in the car on wednesday to have a burnt out bulb replaced, so I will see what happens when I tell them that the noise is still there. Hopefully they can find something this time.

Mat

 

I think I am going to take it in as my warranty ends in two months...

Wish me luck

Tom