intermittent excessive vibrating

[Paul5]

Hi, I am new to both this forum and to driving the S Type jag which so far is great. I have had the car for around 3 months and it has just developed an intermittent fault. The car vibrates quite excessively for around 5 miles then seems to smooth its self out. The last time this happened, I pulled over, but the engine ticked over beautifully but once pulled away again the vibration was still there for around 5 more miles then ok. This happens around once a week.  The steering wheel picks up the vibrations and feels like an unbalanced washing machine on full spin. The jag is a 2.7 Diesel 2007. Any help would be most appreciated. 

[Old Peter]

Hi Paul, and welcome to the club.

 

We have similar cars down to the year!

 

I am not an engineer, but  I had a similar problem in a Rover some years ago.  The cause was a damaged tyre and the vibration came and went.  It could be worth checking the tyres out, particularly the tront tyres.  Also check that there is no play in the steering.

 

The other cause of vibration could be something loose, possible the exhaust. 

 

Regards,

 

Peter.

[red-z]

Hi Paul,

You don't say if the vibration is related to road speed or engine speed.  If road speed then I agree with Peter, your problem sounds like a tyre (or wheel) balance issue, or possible steering.  I'd get them checked a.s.a.p.

If it varies with engine speed (rpm) then it could be fan blade, or one of the belt driven items loose (i.e. alternator, ac comp, water pump).    I once had a Cortina with a nasty vibration between 1800 and 2200 rpm.  Above or below that the vibration disappeared.  The cause turned out to be a broken mounting bolt on the alternator bracket.

[Paul5]

Thanks for the tips. I think it will be a process of elimination until I get down to the route cause of the problem, starting with the tyres.

 

Many thanks for your response. Paul

[Paul5]

Just a quick update. The cause was the offside brake calliper sticking and heating up the disk as I found out to my cost on the A1 today. Thanks to Peter and Robin for the advice. Great help. Jag has been towed to the garage for repairs.