My Skoda Superb is a 13 plate and is used as a taxi. Everything with the vehicle was as perfect as I could expect until I was sent on a job that involved travelling down a rough track. The track was not pot holes or up and down, just a level rough surface that caused everything to judder whilst travelling in first gear and 4 mph for a total distance of 3/4 mile to a mile, there and back to the road.

 

When back on the road, which was a smooth surface, there was now a slight vibration that was not there prior.  Noticeable straight away as before I had a very smooth ride.

 

I reported to my mechanic the issues and we re-balanced the front wheels.

 

That had no real effect other than to eliminate the tyres.

 

Since then, which is now about a month, we have checked the following:

 

All 4 tyres have been balance and wheels checked

All parts of the suspension have been checked for any damage or wear to at least MOT inspection and the only noticeable issue was off  side gaiter showing a slight split which is now due to be replaced.

 

A road test by my mechanic was not conclusive as he rarely drives the car to be able to compare its status, whereas I am in it every day. He didnt find what he would consider a problem

 

Another tech garage I have used in the past did a brief test drive and he immediately suggested a near side wheel bearing, adding he could feel a slight vibration at the steering wheel. There was no noise from the bearing, and further discussions with my mechanic and the Skoda dealership in my area dismissed the likely hood of a bearing.

 

The problems seem to be compounded by the feeling the engine is not running as smoothly as it was, this can sometimes indicate that there is a variation in fuel quality, which, because of the amount I use in the job, I can notice differences.

 

Noticeable in the vibration is that a journey at speed on the motorway for the purpose of completing a DPF regen, the vibrations seemed less, yet on country lanes at speeds of 20mph in 2nd or 3rd gear, particularly on the afternoon school runs, the vibrations/more running seem a lot worse.

 

Its difficult for me to describe the driving problems as whatever is causing the vibrations is affecting the way the power to the wheels seems to drive the car.

 

The conundrum is that I am 100% certain that the problem was caused by approximately 10 minutes of constant vibration to the vehicle in 1st gear at 4mph.

 

My mechanics last thought while we were throwing ideas around was that it might be the differential bearing, As I did a few braking tests, there was no noticeable issues with the way hard baking was affecting the wheels

 

Tyre pressures are kept at 40psi which I was running at prior to the trip down this lane, so everything prior to that journey has the same value.

 

Gearbox mounting seems ok, but we have yet to check other mountings.

 

If anyone can throw some suggestions they would be gratefully accepted.

 

I wouldn't be too quick to blame the bumpy road. You may not have noticed the vibration until the rough travel made you pay a lot of attention to it.

 

The sound insulation in the car is good enough that you may not hear a worn bearing. You mention a split gaiter: if this is on a CV joint then it's possible that the joint is dead and needs replacing. It would certainly  cause vibration if a CV joint is gone.

 

You don't mention what wheels your car has. The 18" ones can buckle if driven over very rough ground. Badly buckled wheels could result in vibration. You would need to have them checked by a competent tyre fitter.

 

If you turn towards the drivetrain, a worn out DMF in the manual or DSG would cause vibration. Worn injectors could cause vibration too. You would need a fuel injection specialist to figure that out.

Hi chimaera, thank you for your reply. I am in a position that I know the before and after how the car handled, and appreciate its very difficult to convey that to anyone who might get in the car and drive it to test. We will be investigating the gaiter next week, though there is no grease coming out. The wheels are standard supply fitted with Toyo tyres, fitted and balanced by my mechanic. We did a very close scrutiny of wheels and the balancing is as accurate as one can get. This vehicle has a solid flywheel so we can rule out DMF.

 

The injectors were checked by a specialist VW garage I have used in the past and there were no errors. I thought that the vibrations might have disturbed soot in the DPF, but the reading was 12 which I was told was fine, so regen is working and there is no blockage of soot. 

 

 

The drive you describe is not really bad enough to break something out of the blue.

 

Human perception is notoriously unreliable - ask any experimental psychologist. This problem has probably been building quietly for a while, but you're noticing it now because the bumpy drive heightened your perception of it.

 

9 minutes ago, Woodhall said:

We will be investigating the gaiter next week, though there is no grease coming out.

There may be none left and this could well be the culprit.