General Panda Cross - Intermittent Vibration??

[Spinoli1]

Hi Fiat folk. I've had my (new to me) Panda Cross for 10 days now, clocked up about 500 miles. I've done a fair number of motorway miles and on 2 occasions (only) I have felt the quite chunky vibration through the chassis (50 to 65mph), which only lasts for about 30 seconds.
It feels like what I would expect an out of balance prop-shaft to feel like, or a failed centre-support-bearing - but its only happened twice in 500 miles and then for only 30 seconds each time. If it was either of those things I would expect it to happen all the time, surely????
Can anyone advise me please?

 

[Herts Hillhopper]

There are a couple of earlier thread about this subject... try the forum search as i think they did get to the cause in the end

 

[Spinoli1]

Thanks HH. I have done some searching and there are plenty of threads about worn/unbalanced prop-shafts and prop-shaft components, none though that are definitive. What I'm really trying to understand is whether the fact that it has only happened twice in 500 miles and then for only 30 seconds-ish each time still means -
a) It is typical sick prop-shaft symptoms
b) Could it be anything else?
c) Whether it is an urgent fix or can be done when time allows

 

[euroben]

Thanks HH. I have done some searching and there are plenty of threads about worn/unbalanced prop-shafts and prop-shaft components, none though that are definitive. What I'm really trying to understand is whether the fact that it has only happened twice in 500 miles and then for only 30 seconds-ish each time still means -
a) It is typical sick prop-shaft symptoms
b) Could it be anything else?
c) Whether it is an urgent fix or can be done when time allows

Good luck with this. I have never found what causes this in mine. No garage can find anything wrong with it and it’s intermittent so never does it when needed at the garage. If it’s not the obvious, propshaft bearing, odd tyres etc like in previous posts, then you may have to wait until something drops off or gives up. If you do find the cause, please do come back to post what it was.

 

[Herts Hillhopper]

Thanks HH. I have done some searching and there are plenty of threads about worn/unbalanced prop-shafts and prop-shaft components, none though that are definitive. What I'm really trying to understand is whether the fact that it has only happened twice in 500 miles and then for only 30 seconds-ish each time still means -
a) It is typical sick prop-shaft symptoms
b) Could it be anything else?
c) Whether it is an urgent fix or can be done when time allows

One thing that I think might affect it is un-matched tyres -- both in terms of brand (tread pattern) and wear levels. In order for the 4x4 system to work prop[erly (where it's watching the rotation speeds of the wheels), all four tyres ideally need similar rolling diameters and rolling resistances. Usefully, the 4x4 Panda seems to wear front and rear tyres fairly evenly, but if not a bit of front-to-rear swapping might be needed now and again.

 

[Funky Spike]

One thing that I think might affect it is un-matched tyres -- both in terms of brand (tread pattern) and wear levels. In order for the 4x4 system to work prop[erly (where it's watching the rotation speeds of the wheels), all four tyres ideally need similar rolling diameters and rolling resistances. Usefully, the 4x4 Panda seems to wear front and rear tyres fairly evenly, but if not a bit of front-to-rear swapping might be needed now and again.

This.
I could have sworn I had a wheel bearing going until I replaced the tyres.

Spike

 

[Spinoli1]

Thanks for your responses, Guys. New matched tyres all around, so I can cross that off the list. I've booked the car in to go up on the ramp next week for a look-see by a good local garage - that may reveal something (hopefully not too much rust!!!). I'll report back with any findings.
If it just an occasional, intermittent occurrence that noone can diagnose, I'm happy to live with it. I just would like to be confident the prop-shaft isn't going to snap at 60mph and catapult me or my wife through the windscreen.