Bit of a hard one this to explain but when I'm changing gear mainly on the downshift and also coming of the accelerator pedal as if to brake, the car jerks a bit as though the gearbox is loosely connected to the engine. I once had this on a mini and it was knacked engine tie bar bushes. Anyway just wondering if it's the engine mountings cos it's done 170K, I've changed centre bearing and rear gearbox mount but it's still there.Are there any other gearbox mounts?? How hard is it to change the engine mountings and are they an arm and a leg?????

thanx in advance anyone!!!!!!!

Jonny

Doubt if its engine mounts - the V6 doesnt move around like a 4 pot fwd. Its well balanced plus all those boost pipes hoses and the turbos and exhausts would not like to be joggled about too much. Try bliping the throttle cables under the bonnet and see how much torque movement the engine is giving on its mounts.

Maybe its transmission backlash. Incidentally is that 170k miles? Must make yours one of the intergalacticist Zs here

yes indeedeeee!! 170K miles and counting..

forgive me but what is transmission backlash???

cheerzzz

Jonny,

If the jerkiness is fairly mild, it may be down to corrosion on the Throttle Position Sensor switch. On gentle throttle in higher gears do you get a sensation of the car shunting a little and an erratic idle (bit high sometimes)? Coming off the throttle the engine may not return to its correct idle straight away, a delay may be felt as a gentle jerk as it occurs sometime after your senses expect it and your foot had commanded it. I have had this occur twice in the last 18 months and cleaning the connections resolved it. If you suspect transmission backlash I would expect more of a 'clonk' type noise. By the way my Z has covered 150K miles so you are not alone in the mega-mileage stakes. Good luck.

Paul N