Vibration issue (only accelerating)

[Agadou]

I'm trying to explain my problem (i'm french).

My car : 850R automatic 1997, 76 500km

I bought it for 2 monthes.

There are strange vibrations when i accelerate only ! When i take off my feet of the throttle pedal, it doesn't happen anything.

Vibrations = as if a wheel were loosen and moved laterally ! (they don't)


Could it be an axle ? or engine mounts ?

[Tomcat]

Check the top engine mount, these are prone to breaking.

[TenaciousC]

has it always done it, or only during the recent cold weather?

Does it happen at all speeds in all gears or only some?

C

[Agadou]

It happens at all speeds except when i throttle very slightly (for example at 70mph continious)

Cold or not it happens.

Upper mount is a poly one (like powerflex)

[Flatout Phil]

Wishbone bushes? Ask someone to drive the car backwards and forwards about 1m - each time apply brakes hard. Watch for any lateral movement on the front wheels. This would show worn bushes. 850 wishbone bushes fail when lots of power is used. Sometimes you can see notice worn bushes when you brake - the steering wheel pulls to the left or right as the car comes to a stop.

Check the constant velocity joints for split rubber gaiters.

Also lower engine mount by right-hand drive shaft.