So every morning upon first start up the car starts and idles fine but the 7 mile trip to the expressway while traveling between 35-50 mph at a steady speed the engine surges all of 50 rpm. Yes I typed that right, 50, so if the rpm is 1500 it surges to 1550 but not 1600, same if its at 2000, it will go to 2050 not 2100. It will do this during the whole 7 mile (warmup) trip but as soon as I get to the expressway and start rolling at 75-85 with the cruise control on it doesn't do it.

Any thoughts on this? 40 years of driving, 35 of having misc. Jaguars and I've never had this happen.

Opps, its the XJ8 NOT the XKR

Thank in advance,
John

 

Both our Jags an XK and my XJR will do this is you do not let the cars RPM settle before leaving the Garage in the morning, if we just jump, turn on and go the car will not settle for a while. My car when started idles at 1000 then goes up to 1200-1300 the after a 20-30 seconds starts to drop to about 800 then is as good as gold. My wife's XK is the same but revs to about 1600. The dealer has reflashed both but they still do it.try letting the revs settle before starting out in the morning seems cats don't like to be rushed.

 

Mine does it too. Typically when driving between 50 and 60 mph. I do know to let my RPM's settle before driving. It does seem to help sometimes. I have been wondering if this is more of a tranny or torque converter thing? I dunno. Letting the car settle does work though.

 

My 04 XJ8 with 104K was doing that as well. Had the trans fluid flushed and TCM flashed and no more issue with the slight RPM fluctuation. IDK which resolved my issue; the fluid, or the flash lol.

 

Sounds like you have the 'hunting' syndrome, well known on this forum. It occurs whilst the transmission fluid is warming up, and will disappear when it is at correct temperature. It disappears on the freeway because you are above the speed range at which it occurs.

Nothing to worry too much about. If you don't like it, put the transmission lever into '4' until you get to the freeway, then back into 'D'.

Yes, Jaguar should really sort this one out with ZF, but don't hold your breath !

 

my kitty does it too, figured it was blipping the throttle b/c it was considering downshifting, so as to make a smoother gear change.

I don't feel it, but i see it, and sometimes it blips more than 50 rpm, i have seen it travel 200-500 rpm before.

but on the highway of course, it is gone.

I will try to drive around town with just 4 gears, should save gas and lessen wear as well.

 

Is there no TSB for this issue ?
It seems quite common issue , but I never read an official solution how to handle it..