over inflated tyre.. 82psi!!

[cj10jeeper]

Fair point - though from what've can find out tyres don't actually melt, though they will soften and deform. Not sure at what temperature, still looking. In the meantime, what about if it was left overinflated by the fitter and then heat from a sticky caliper pushed the pressure up more ? Why it took 700 miles for the sensor to decide to alert the OP is still a mystery - why does nobody else think that's weird ??

Melt is probably the wrong term. Agree rubber softens and then falls to bits, rather than turn to a liquid.

Not sure about the sensor. They calculate different rotational speeds of wheels on the axle, rather than pressure. Some test actual pressure which is better and probably a much more expensive system.

I would however like to think I'd feel such a tyre pressure given 2 or 3 psi makes my Zoe dhandle so differently.

 

[Andyoldgit.]

It was only one tyre that was overinflated. I measured it with my digital guage. I know this to be accurate. I use it to set the pressures on the rally car tyres for every event. The tyres were a bit of a problem to fit on my wheels and would not bead correctly. The fitter had to feed in the high presure in order to get them fitted. They went on with quite a pop! Its my opinion that he forgot to release the presure from one of the wheels before fitting it back to the car. As far as i understand the car cant really measure the tyre presure and the system works via the ABS sensors on each wheel. If one is going round at a different speed to the other then it will bring on the light after a predetermined time. Im not sure if thats correct or not! As for the feel of the car, because it was the back axle and not the front i was not as tuned into it as maybe i shoukd have been.

 

[Bing]

Thing is, you'd expect it to set off the sensor as soon as a different rotational speed is detected because it is a puncture warning system. It's weird that it took 700 miles, unless you reset the sensor after the tyres were fitted, made the computer think the speeds on each wheel were normal, and somehow 'natural' warming gradually increased temp & pressure and eventually set it off. Did you reset the sensor ?

 

[Andyoldgit.]

Thing is, you'd expect it to set off the sensor as soon as a different rotational speed is detected because it is a puncture warning system. It's weird that it took 700 miles, unless you reset the sensor after the tyres were fitted, made the computer think the speeds on each wheel were normal, and somehow 'natural' warming gradually increased temp & pressure and eventually set it off. Did you reset the sensor ?

Nope, the sensor never tripped until i was just a few miles from home. I was wondering about your comment regardung rotational speeds. Neither of the tyres were punctured, or in any way flat, so the rotational speed of the wheels will have been identical (ish), the over inflated tyre would not have been any bigger than the nirmally inflated tyre, Would it? Or am i missing something? As it turns out i have spoken to ATS who have said the tyre would not have been damaged by its journey. I also spoke to the AA who have confirmed this. Im happy to accept this and move on. My next worry is the Camber settings as you have mentioned, I guess a trip to the Hunter machine is in order.

 

[Bing]

So if the tyre is fine, then that's good, and an alignment is always a good idea if you don't know if it's ever been done... Because it probably hasn't. Pot holes, kerbings, and just bad roads all throw out the alignment over time. I should really get mine done again soon.

My sensor went off when I had a sticky caliper. It must have been heat that increased the air pressure in the tyre, and as cj has pointed out my tyre shouldn't have been anywhere near 82psi, though I didn't check. So I reckon 82psi would change the rotational speed enough that it would set it off. The mystery is the length of time it took to set it off, which is why I figured it may be the caliper. From what CJ has said, probably nothing to worry about.

 

[mmm-five]

Mine went up to over 42psi when I had my sticking caliper.

It would have been a bit higher during the motorway part of the journey, but I didn't pull over until I'd got to the dealer - but they were only 10 miles further so thought I'd risk it.

 

[Bing]

Mine went up to over 42psi when I had my sticking caliper.

It would have been a bit higher during the motorway part of the journey, but I didn't pull over until I'd got to the dealer - but they were only 10 miles further so thought I'd risk it.

Did your tyre pressure light come on ?

 

[cj10jeeper]

So if the tyre is fine, then that's good, and an alignment is always a good idea if you don't know if it's ever been done... Because it probably hasn't. Pot holes, kerbings, and just bad roads all throw out the alignment over time. I should really get mine done again soon.

My sensor went off when I had a sticky caliper. It must have been heat that increased the air pressure in the tyre, and as cj has pointed out my tyre shouldn't have been anywhere near 82psi, though I didn't check. So I reckon 82psi would change the rotational speed enough that it would set it off. The mystery is the length of time it took to set it off, which is why I figured it may be the caliper. From what CJ has said, probably nothing to worry about.

Somewhat speculation but I don't think +c40 psi would affect the rotational diameter much. The warning system is more designed to catch a deflated tyre where the rolling diameter changes greatly. Once they drop to 10psi or similar they pick it up quickly.
Delay in triggering is they have to compensate for any the left and right turns and come up with an average difference in rotation. Can take some distance, but I'd expect that in a few hundred metres.

 

[mmm-five]

Did your tyre pressure light come on ?

Yes, and I pulled over to see why, as I thought I had a puncture.

Wheel was covered in brake dust and too hot to touch.

As I resumed my journey I started feeling a bit of 'drag' on the car which I hadn't felt before, so just drove to the nearest dealers and got it rectified under warranty.

 

[Bing]

Did your tyre pressure light come on ?

Yes, and I pulled over to see why, as I thought I had a puncture.

Wheel was covered in brake dust and too hot to touch.

As I resumed my journey I started feeling a bit of 'drag' on the car which I hadn't felt before, so just drove to the nearest dealers and got it rectified under warranty.

Yep, exactly the same for me. Though I had been feeling drag and juddering under heavy braking before-hand, and so thought a puncture was the cause. And I didn't have a warranty :lol:

I feel a little vindicated now, but only a little

I guess a binding rear caliper might not provide much feedback that you'd notice at all.

 

[Andyoldgit.]

Thanks for the advice guys, what a great forum this is, Im confident that if i have any further problems one of you will know the answer. As a side issue, i have now lost my locking wheel nut key lol. It never rains in my life. Just a constant monsoon!! My neighbour is an AA tech, so he soon got the bolts out. Just need to get some shiney new ones now.

 

[GreyZed]

Just get a new key from the dealer. Probably one of the few times a dealer solution will save you money. The key type code is on the bolts or get it via your VIN.