Help Please TPMS - I think I might have created my own problem

[jdp1962]

A couple of weeks ago, I swapped a badly-refurbished alloy for one I'd sourced on eBay. The existing one was then sold on eBay. All seemed well until I started getting periodic TPMS warnings on the dash for the right rear - the one that's been swapped. Yet when I check the pressure, it seems fine.

I'm now wondering how the TPMS works. I understand it's based on wheel rotation but am I right in thinking the sensor is built into the wheel? If so, then I'm fearing that the tyre fitter didn't move it over to the new wheel.

 

[Darren92]

Runs off ABS unless you have TPMS High which displays pressure and temperature.

 

[Booboo]

In direct TPMS uses the same sensor as abs & traction control I don't know if your is direct or indirect.

https://www.bridgestonetire.com/tre...ire-pressure-monitoring-system-how-tpms-works

 

[jdp1962]

Runs off ABS unless you have TPMS High which displays pressure and temperature.

I don't have temperature or pressure displays anywhere, so does that make my system indirect?

 

[jdp1962]

This link confirms Audi has used indirect systems since 2011. So I don't need to worry about having lost a pressure sensor, I just need to figure out why the tyre's losing pressure. May just be a shoogly valve, but I need to fix it quick as the car's due its first MOT in a couple of weeks.

 

[weekenny]

Manually check the tyres and if they are ok use the MMI menu to store the pressures again.

 

[jdp1962]

Manually check the tyres and if they are ok use the MMI menu to store the pressures again.

I did that when it first happened; I'm just waiting for the tyres to cool after driving it to work this morning, and I'll do it again. But that won't fix things if air is escaping. I might get the tyre re-fitted.

 

[jdp1962]

So I just checked the cold pressures; it was 23PSI instead of 33PSI, so it's lost 10PSI in seven days. If it happens again, definitely a refit.

 

[rum4mo]

So I just checked the cold pressures; it was 23PSI instead of 33PSI, so it's lost 10PSI in seven days. If it happens again, definitely a refit.

Ah well at least you know that the system is working as intended, I get issues with my winter wheels which I got powder coated as I bought them used from ebay, I think that issue there is that the valve "hole" were not opened back up enough so my tyre fitter just jammed something through them to open them up and must have broken through to the bare alloy side of the holes, so now salty water gets in there in winter which means that every 3 years I need to get the holes cleaned up and new valves fitted!!

I applaud your ability to sell items on ebay, so far, for me it has always been a one way process.(I must change that soon!)

 

[jdp1962]

Well this proved easier to fix than I feared when I started the thread. After resetting the pressures on Wednesday, I checked them this morning and the right rear was down from 33PSI to 28PSI. For an assortment of reasons, I wanted this sorted today, so with a little trepidation, I drove a mile to the only tyre place open around here on a Sunday, the local Kwikfit. I struck lucky as I was greeted by a young guy who was clearly a car enthusiast and not just a tyre fitter. His eyes lit up when I rolled the S4 into the bay, and he purred "That's beautiful, man!" as I got out of it.

Told him the problem, and he whipped the wheel off, laid it flat on the floor and poured water over the valve. Immediately it started bubbling, so we had the problem right there. He replaced the valve without having to remove the tyre from the wheel, so no re-balancing necessary. The whole thing was done and dusted in ten minutes, during which we had a very appreciative conversation about the car, and at the end, there was a handshake and no charge.

 

[scotty76]

Great result @jdp1962. Kwik Fit fixed a rattling exhaust for me one Sunday without charge in similar circumstances. Guy liked the look of my SEAT Leon Cupra.

Like you I won't go there by choice as it's just too variable based on the staff churn. My local tyre place has been the same guys for 13 years now.

Really glad you got it sorted easily.