New to the forum...a great resource! When my 2004 XK8 transmission is in 6th gear and I start to go up a long slight incline, I press the accelerator slightly to go up the incline and I feel a shaking in the car (similar to how a car with a manual transmission would react if in too high a gear). It seems like the transmission should be downshifting to get up the incline, but does not do so. I have to really give it some gas before the transmission downshifts to get up the incline. There is also a "groaning" noise that comes from the drivetrain when I am pressing the accelerator in order to maintain normal driving speeds on roads and highways. On a whim, I switched to sport mode and the problems were not as prevelant, but they still occured. Any thoughts as to what the issue(s) might be?

 

Do you have any OBDII codes or Restricted Performance, Fail Safe or Transmission problems indicated on the dash?

 

Welcome to the forum westy,

I've moved your post to the tech section, don't forget to post an intro in the new members area.

 

I have no codes or messages indicating any problems with the transmission or engine. I do notice when I accelerate quickly from 35 mph up to 70 mph that the vehicle seems to feel like it "surges" as I accelerate...I notice a very slight dip in the rpm's on the tach as this happens. Thanks!