Lumpy engine/misfiring

[bl52krz]

It could be the rear mountings on the wishbone’s. My friend had a slight vibration on the steering wheel, and also needed two new front tyres. While they were being changed, the tyre fitter called him over and said that he thought that he had a problem with a joint or something, because as he was tightening the wheel up, the wheel was moving backwards and forwards somewhat. Turned out to be the above rear mountings. Once fixed with new bearings, the vibration disappeared.

[freelancer]

Tks bl53krz,

I'm having two new front tyres fitted this Wednesday, so hopefully full resolution right there.
As a check, I had the front wheels separately balanced on Monday (one step at a time) and the tyre fitter straightaway reckoned the uneven wear, minor cracks and maybe a flat spot(s) on the front tyre(s) was the problem.
But your comment has me worried/wondering, as the main part of the initial MOT fail 6 weeks ago was a difficult piece of welding required at the offside rear subframe mounting.
Just for my understanding,, when you say "...rear mountings on the wishbones". is that the rear mountings of wishbones at the front? And, when you say "once fixed with new bearings", sorry what bearings is that?

[freelancer]

Two nice new Avons (replacing flat spots/uneven wear? ones) fitted this morning -but shuddering above 65mph still there.

Front discs were advisory on MOT so poor old vehicle going back on Friday now to check if they are warped...!

[Steady Eddy]

I think he means rear bush on front wishbone could be shot.

[Lagetha]

Originally Posted by freelancer

Tks bl53krz,



I'm having two new front tyres fitted this Wednesday, so hopefully full resolution right there.

As a check, I had the front wheels separately balanced on Monday (one step at a time) and the tyre fitter straightaway reckoned the uneven wear, minor cracks and maybe a flat spot(s) on the front tyre(s) was the problem.

But your comment has me worried/wondering, as the main part of the initial MOT fail 6 weeks ago was a difficult piece of welding required at the offside rear subframe mounting.

Just for my understanding,, when you say "...rear mountings on the wishbones". is that the rear mountings of wishbones at the front? And, when you say "once fixed with new bearings", sorry what bearings is that?

See Arctic's post in members parts for sale... Unipart Bearings X 2. These are the front lower arm, rear bearings... Had the job done on mine recently with parts bought from Arctic/Steve. 🙂

Sent from my Note_7P using Tapatalk

[freelancer]

Would a duffed rear bush on a front wishbone only make its presence felt at high speeds?

Vehicle had just had a MOT, could it have been missed?

[Lagetha]

Originally Posted by freelancer

Would a duffed rear bush on a front wishbone only make its presence felt at high speeds?



Vehicle had just had a MOT, could it have been missed?

Easy test, jack up front, see if any front to back motion possible while gripping the wheel... Before I had mine done OK on smooth fast roads, a little knocking on some uneven surfaces, and jittery steering at low speeds in tight turns etc.

Sent from my Note_7P using Tapatalk

[SD1too]

Originally Posted by freelancer

Would a duffed rear bush on a front wishbone only make its presence felt at high speeds?

In my experience, no. I didn't get any shuddering at any speed but after I'd fitted new bushes the car's handling around corners noticeably improved.

Were the wheels balanced when you had the new tyres fitted?
Have you had the 4 wheel alignment checked following the difficult welding?

Simon

[freelancer]

Tks for comments.
Brake and disc inspection this morning. Discs could do with renewing but not warped. (Juddering is not happening when braking).
Wheels were balance checked before new tyres and were fine and again after new tyres fitted. But wheel alignment not done.
Will get car road tested by knowledgeable car person this weekend. In discussion with someone else this morning his main concern was to hear of subframe at rear being disturbed for welding job. He wonders if rear bushes are the source of the altered handling/vibration.

[freelancer]

After test drive by experienced 3rd party, the issue with vibration has been now been sourced to a shocking find whilst checking a suspicion with the driveshaft on the offside.

On disassembly The inner bearing of the driveshaft at the offside had a full roller complete with needle bearings missing from the three bearing tripod on removal of the driveshaft! Oh yes!

The likelihood is that it must have been dropped/misplaced when manipulating the shafts at the time of the MOT repairs almost 2 months ago.

Anyone with source of replacement part for a 2.5l KV6 inner driveshaft (offside) please let me know.

Plenty of wise after the events here including:

I should have taken the car for a full road test after MOT repairs and not waited several weeks before first journey at speed (55-60mph and above)

I should have realised and described vibration more clearly was " slightly engine misfiring -like" but not "engine misfiring". Thus a drivetrain issue not a powertrain one necessitating the wait for a T4 test.

I should not have been diverted from considering that the welding work at the rear (same time as MOT repairs ) was the issue. (I had been told "we may have to issue the subframe" when subsequent inspection shows the subframe was not moved).

It was not front tyres or wheel balancing issues (as 2 different tyre places had recommended as very likely!)