Vibration apparent on acceleration.

[C30Vehicle]

My 2009 C30 turbo experiences vibration/shimmying on acceleration. The front-wheel drive axels were replaced; yet the vibration continues upon acceleration.

My mechanic made a suggestion that worn 'spark-plug wires' may be a factor; which may also explain another problem. The vehicle sometimes doesn't start right away; that it's sometimes necessary to turn the ignition key two, maybe three times before the engine starts.

[Cees Klumper]

Mechanic should see whether there are any codes. Ignition wiring sounds odd, but perhaps a coil is failing. I have the same issue with my C70 and upon inspection found the driver's side driveshaft to have some play so ordered a new one through FCP. Not original Volvo ($$$) but their OEM equivalent, at something like $350. Waiting for it yo be delivered. I know you say your driveshafts were just replaced, but are you sure aboug the quality of what was installed? Apparently there is a lot of poor quality in cheaper driveshafts out there. Good luck and please keep us posted.

[Cees Klumper]

Sometimes we get lucky: this morning I set out to replace the driver`s side driveshaft to address my slight vibration on accelleration. Turned out a previous owner mechanic had failed to properly tighten the bolt that keeps the driveshaft tight against the wheel hub! The bolt was just completely loose and the only thing keeping it from falling off the car was the center cap on the wheel! Also it was an incorrect type bolt and washer. So I installed the bolt that came with my new driveshaft and took it for a test drive. Vibration totally gone (I am sure the stresses during accelleration made the shaft move inside the splined hub causing the vibration). I am saving the replacement driveshaft for later, when the original one has worn out. Will probably be a while. Sometimes we just get lucky, this was the easiest fix ever.