Hello,

Every morning, as my 04 XJR warms up, the rpm's will surge about by about 100. As I am driving down the road, I can see the tach changing by no less than 100 rpm. Go's away as the car approaches normal operating temperature.

Any ideas? I'm thinking possibly the fuel filter. Since thats an easy fix, I am going to change it anyhow, though I doubt the car needs it with only 32000 miles!

 

Oops, sorry, I had to retract this. I thought I was answering another post and realized this was in the wrong spot. Wrong response to OP question.

 

Several of owners of early production 04 XJs have experienced this problem. Some have replaced their torque converters and that has seemed to do the trick (but it's expensive). The dealer says it's the TCM software however "reflashing" doesn't seem to fix it. They reflashed mine three times in an effort to fix this issue and it hasn't worked; it's been an issue since my car had 27k on the odometer. Mine too stops doing it when it warms up. I'm now at 65k and is hasn't changed a bit; no better, no worse. You can search for the thread "hunting transmission" and you'll see a lot of comments on this.

Steve11 - what's "MAPS?"

 

My 2004 XJ does this as well, the dealer tried several times to repair but was never able to eliminate it. It happens just before the engine reaches full operating temperature. I find if I keep it in 5th gear until full temp is reached it does not do it.

Andrew T

 

My 04 is the same way. Reflashed the TCM and fluid changed and still does it. I have 82k on my car and so far no additional harm that I know has happened by living with it.

 

Yep, it's pretty common, it's the torque converter lock up clutch engaging & disengaging repeatedly during warm up, there is a TSB for it, as already said, the TCM reflash is supposed to fix it they should also flash the PCM as part of the process, but if it fails the only cure is new torque converter, many people live with it, I've never seen anyone report a total transmission failure 'cos of it. Some people have reported the effect is reduced in sport mode.

 

I normally leave mine in 3rd until it warms up or I get out on the highway.

 

It's not a bug, its a feature !

MIne does it too.

 

Ditto here. 54K on my 04 XJR. Sought similar solutions to no avail.

 

Also see "transmission hunting"

 

MAPS is the acronym for manifold absolute pressure sensor.