I have a 2014 XK convertible. The suspension seems to jiggle about a bit (like small bumps in the road) which don't exist. I had all new tyres fitted and wheels balance and it seems a little better but still has a lumpy feel. The wheels all seemed true on the balance machine. Alignment was alsoo checked and adjsuted to spec except rear camber which they said couldn't be adjusted and was only marginally out. The suspension bushings all seem to be good - only on a quick inspection. I would like to eliminate the problem if possible - any ideas? The car has 20" wheels but the probelm doesn't seem to relate to feeling bumps, it happens even on very smooth road and at low speed as well as high.

 

Miles?

 

Mine tends to follow worn surfaces, I don't feel any play in the steering. I just assume the wide tires are following road wear from all the traffic. I had a land cruiser with really wide tires that did the same - shop could never find any issues, they said most likely the wide tires following road wear.

 

Sure its not a motor mount?

 

48,000 miles. It’s going in for its big service tomorrow. I’m hoping it might be a misfire and will be sorted by new set of plugs - but doubt it.

 

I’m pretty sure it’s not engine mounts. I have run along very flat downhill in neutral at the “bumping” is still there. I also tried what I saw in one of the forums - lift the bonnet engage drive with the brake on and watch for movement- it seemed OK. I did wonder about trying freewheeling with the engine off to rule out misfiring but I don’t think it can be done without the steering lock going on.

 

Sure, the car does “tramline” at times on certain worn/ tracked roads. The problem I have is like going over small infrequent bumps - when there are none. It doesn’t seem to come through the steering much, and doesn’t seem to be worse or better when cornering either way. The car just seems to hip/twist then hop (probably a slight sideways feeling). It’s quite subtle but very annoying.

 

Sport mode off and lower tire pressure keeps the jiggles down.

 

Had all mounts and suspension bushes checked and all good. Will try the lower tyre pressure tip from mhm. Dropped from 33/36 psi to 30/33. Will try a set of borani wheels I have in the spring and see if any better.

 

Have you checked the Prop(drive) shaft & U joints? Just a thought!

Cheers, Adrian

 

steering tie rods?

 

but you said the rear was “marginally out”. I am expecting it to be better than that.

Rear subframe mount bushings?? Others? The top damper isolators?
I suppose I am really suggesting “marginally out” is not a standard situation for discerning individuals like us ;-)

 

Thanks Adrian, not checked that one. I guess an out of balance prop shaft would cause vibration at certain speeds?

 

thanks Guy, the dealer checked all bushings and said they were good. They also said they couldn’t detect anything unusual- so perhaps I am just expecting a smooth ride which the car can’t deliver. Will investigate more in the spring with alternate wheels.