Having just had n/s front suspension bushes, 4 disks/pads, 2 front tyres and rear sills cut and repaired, plus paintwork I thought I was all set. I noticed when I got the car back one of my pZero's was flat. It inflated fine and all has been well except...

Three times now, most of my trips are around town and a few on motorways, when driving a vibration starts to kick in and isn't related to a specific speed. I thought I might have a flat so pulled over, checked all 4 tyres which were good and drove off gingerly but all was good for next 50 miles and no issue on return journey.

This weekend it happened again, a quick stop to check pressures and I drove off but some of the severe vibration returned but next stop at a junction saw it disappear for rest of that outbound and none on the return journey.

Might my issue be loose/worn rubber inside the run flat? On 2 of the 3 occasions I took off from a roundabout and then a mile? or so later it kicked in. I was wondering if it is like a wet towel in the spin cycle of a washing machine where it has bunched?

Any thoughts welcome.

Angus

 

Are you sure it doesn't happen at certain speeds? Because it kind of sounds like a wheel is out of balance.

 

sounds like a severely worn rear wheel bearing.

 

Thanks both.

I can drive 0-70 mph and all is perfect for most 50 mile journeys.

On the two occasions where it started to kick in were after taking away from roundabouts. Now I got going up to speed a mile or more on and then slowly the vibration kicked in (at same constant speed) and just continued to grow to something 7 out of 10. Past wheel balances i’d class 1-2/10.

It just passed its mot hence all the work but they may well have missed the rear wheel bearing. Will ask them to check it out.

Garage going to check rear diff bushes incase that’s the issue. Who knows what else might be lurking in that rear dark place.

angus

 

I have had a tire that a belt was shifting around in that behaved like that. Sometimes smooth, sometimes extreme vibration, no particular pattern to speed or conditions. Rebalancing did not identify it and I only figured it out when the tire disintegrated while driving.

You didn't mention if the flat was one of the new or the old tires, but I would focus on the one that was flat. If the car was moved around in that condition it could have damaged the tire internally.

 

Raise the front and rear tires. Wheels on for leverage, give them a good shake at the 3 and 9,,, and 12 and 6 positions and see if you get any movement what so ever. Think about the bearings and the hub at the wheel center - and also upper and lower ball joints and see if they are firm. Can you see the rubber boots on the ball joints? Are they intact?

 

AngusJam,

I've heard bad things (Such as your Problem) about Those "Run-Flat" Tires....Have a good Tire Company check them out, as you may have a bad Tire.....Interested, please let me know how it turns out!

Billy Clyde @ Cinco Ranch

 

Angus,

I assume this is rear end vibration because you would almost certainly feel something through the steering wheel if front suspension/steering was the source.

Other than questioning the reason for the flat tyre when you collected the car, the rear sill work makes me suspect rear suspension mountings as a possible cause. The front 'A' Frame bracket is likely to have been removed for access and the large round bush could be damaged. The weight of the car prevents the suspension falling off but it's possible this could be setting up a random and non-speed dependent vibration. Anything on the driveshaft is normally speed related so I think that can be discounted.

Graham

 

Thanks Charlie & Billy - It was one of the older tyres, will go to the tyre shop tomorrow and ask if they can take it off to check - If full of rubber they get a new tyre as I don't fancy it disintegrating on me!

JayJagJay - I'll get them to check the bearing and ball joints when at it.

Graham - I forgot (how could I) that they replaced both Rear Suspension Subframe Mounting Brackets (rusted through) and they said the bushes were okay! Still original so I was surprised.

Let me report back post tyre/wheel check.

thanks to all

Angus

 

The rear tyre, which I suspected had been run flat was in good order but as it was getting lowish on tread I had it renewed. :-(

I'm going to drive it for a month or two until I can get a clearer idea as to how/where/when the vibration kicks in and then back to the garage for a closer inspection of their work (which they are sure it can't be) and some of the rear end bushes/bearings.

Will update in 2022.