Hi

As my VRS is approaching 7000 miles and the front tyres are looking a little worn I thought I would swop the wheels front to back. So I pulled the trolley jack out of the garage and peered under the car to find a suitable jacking point, there's not alot there but decided on a large alloy wishbone mount, which if you lifted the car a bit the jack just got under. I could not find a suitable jacking point at the back so I used the car jack.

I removed the wheels to find that the wheel bolts were covered in white oxidation, which was quite alaming for a car just 11 months old. Anyway I swopped the wheels put some copper ease? on the bolts and put the wheels back on.

Then I thought I would check the tyre pressures as I had not checked them since the summer and thought they might be different front to back. I was amazed that the pressures had dropped about 6-8 psi. I had been under the impression that the Tyre Inflation Pressure-Control system was monitoring the the pressures for me. It appears that this system only monitors unusual changes in pressure, say if you get a puncture, it does not pick up a gradual even loss of pressure over time.

As a word of warning to other Briskodians I would check your wheels have not corroded onto your hubs and that just because you have a tyre pressure warning light it is not an excuse not to check your tyre pressures.

I had a puncture on my last Octy and I heard the sound of the tyre slapping around before the TPM went off!!

so the tpm is a gimmick???

It wouldn't an option i'd order.

i would have asked to swap it if i could and also if i had known.

I've found that the pressure monitor picks up on mine, but only after a tyre has lost about 0.8 - 1 bar of pressure. Found this last week and today, so going in to have it checked at local tyre dealer (who fitted the tyre originally).

But I agree it doesn't pick up smaller changes in pressure.

mine doesnt pick up on any, even in the summer when i had to add a lot of air.

TPM has been a lifesaver TWICE for me, once detected a drop in pressure (althought to look at it looked fine) and discovered a screw embeded in one of the front tyres and a similar incident the second time so for me it's an option I'd rather not be without.

It's never gone off on mine but I have had to put a reasonable amount of air in the tyres at times.

Next time I need new tyres I'm going to let half the air out and go for a drive round the industrial estate first and see if it notices

let us know the outcome, im one who will be interested!!

I had my front tyres changed a few weeks back, they put too much pressure in them, the alarm went off about 2 miles from the fitters.

Next time I need new tyres I'm going to let half the air out and go for a drive round the industrial estate first and see if it notices

I dont think the TPM works like that, afaik it detects a change in pressure ie. will pick up a fault as you are driving the car so it would'nt necessarilly detect a flat tyre or reduced pressures from start up.

It works on the rolling circumference of the tyres by looking at the relationship of the wheels via the ABS sensors. Putting new tyres on obviously increases the overall circumference so it could well be that setting it off when new tyres are fitted. Mine used to go off with new boots on the car.

The more sophisticated systems have pressure transducers in the valve assembly sending real time info back to the on board computer.

It may well be gimmicky but it might give you that half second warning on the motorway that could make all the difference.

Hi

[I removed the wheels to find that the wheel bolts were covered in white oxidation, which was quite alarming for a car just 11 months old. Anyway I swopped the wheels put some copper ease? on the bolts and put the wheels back on.

This white oxidation seems to be quite normal on all VAG wheel bolts. IIRC there has been considerable controversy over whether wheel bolts should be greased. I think the suggestion was that greased wheel bolts could be over torqued and therefore be under too much stress. I can't remember whether the thread (!) was on this forum or elsewhere.

It's also quite normal for alloy back wheels on VAG cars to seize on to the hub and require strong arm tactics to get them off. It's certainly a good idea to remove the rear wheels and grease the contact faces.