How often do your tyre sensors go off?

[CanadaA3wales]

Hey
I thought my tyres had a slow leak or were not sealed right, but they are all fine.

I know it will go down over time but I am not sure how long or how much pressure needs to go before the sensor kicks in.

I put 35psi in all around 16" , this was about 3 weeks ago and the sensors went off again.

Is this normal? My last car did not have the sensors so I am not sure how often these go off and usually how much pressure is lost over a few weeks and when to be worried?

Thanks all

 

[The_Ironist]

I try to pump my tyres once a month but where I miss it it rarely goes off. Over lockdown I went a few months and still didn’t trip it.

A few weeks isn’t right.

Have you been resetting the tyre pressure monitor on the MMI when you do them?

 

[AllanG]

Mine have never gone off, but I do check my tyre pressures fairly regularly.

 

[JohnM100]

Per above, how often do you put air into the tyres and reset it?

I have had the odd spurious warning but regularly go 6 months without it going off.

I did notice an increase in spurious warnings when my normal route was closed and the new one had a lot more concrete roads. Checked tyres and reset it - all fine until my normal route reopened and it went off again when back on tarmac. One more reset and all good.

 

[eribaMotters]

One false warning so far in 17 months and 11K miles.

Colin

 

[rafletcher]

Hey
I thought my tyres had a slow leak or were not sealed right, but they are all fine.

I know it will go down over time but I am not sure how long or how much pressure needs to go before the sensor kicks in.

I put 35psi in all around 16" , this was about 3 weeks ago and the sensors went off again.

Is this normal? My last car did not have the sensors so I am not sure how often these go off and usually how much pressure is lost over a few weeks and when to be worried?

Thanks all

I don't think you have "sensors" at all. Audi have usually used an "indirect" TPMS system that relies on the ABS sensors, and not a "direct" system that uses in-tyre TPMS sensors. (this applied to my '14 A4 and my '18S3). This IMO is a good thing, due to the expense of sensors, the complications if you have winter and summer wheel sets, and the fact the foam repair kits kill not only the tyre but the sensors.

So, assuming yours is indirect - you pump up the tyres and set the "pressure" in the MMI - the system works by comparing rotational speeds for the wheels using the ABS sensors. If one wheel starts to rotate at a different rate (due to change in circumference due to loss of pressure) then the warning will come on. IME it took a decent drop in pressure - more that 10 psi on the 18" 45 profiles on the A4 - to get it to show up - and with 35 profile tyres even more so!

I'd suggest that you may have a slow leak (not necessarily a puncture - mine was cured by getting the garage to pop the tyre and use some tyre sealant on the rim) that is showing up. Could be valve, could be a corroded rim, could be poor refurb paint lifting at the bead..

If you're particularly concerned get an aftermarket TPMS system - for some reason the forum is stripping out the hyperlink I posted - search for Jansite TPMS on Amazon

These use sensors on the valve caps - but beware - there are LOTS of stories of the caps corroding to the valve stems and being impossible to remove, thereby necessitating a new valve. A decent grease on the threads and a monthly check avoids this.

As side note. I (briefly) had a Toyota Corolla with direct TPMS. I was warned that on frosty mornings the alarm WOULD go off (assuming I'd pumped up the tyres at a relatively warm temp) due to the drop in pressure caused by the cold - so they're very sensitive.

ETA - generally the warning has never gone off in my Audis, unless I've had a puncture or a leak. I check my tyres about once a quarter!

 

[DescendDescend]

I guess you are writing about the Tyre Pressure Monitoring System and not the Tyre Pressure Loss Indicator (using wheel speed sensors)?

I don't have TPMS but the loss indicator was generating a right rear alarm after a couple of hours on several consecutive drives. After numerous pressure checks and a tyre inspection I swapped the rear wheels to try and track down the cause. No alarms since the swap.

 

[Wibbly]

In terms of aftermarket, I am using TyrePal without problems. An earlier version of this https://www.tyrepal.co.uk/product/solar-colour-monitor-kit-4-external-sensors/

Audi TPMS has gone off once

 

[CanadaA3wales]

Yeah I am not sure about what sensor I have, I just fill them up to 35 and then go into MMI and asks me if I would like to set the tyre monitor setting up so I press yes and it resets to what I just filled up on, but 2-3 weeks later its gone off again.

I will have to keep checking my tyres to find out which one is bothering me and probably get it resealed.

Its not the most advanced kit, I think it just monitors something basic, its only a standard 2014 2.0 sport A3

 

[rafletcher]

Yeah I am not sure about what sensor I have, I just fill them up to 35 and then go into MMI and asks me if I would like to set the tyre monitor setting up so I press yes and it resets to what I just filled up on, but 2-3 weeks later its gone off again.

I will have to keep checking my tyres to find out which one is bothering me and probably get it resealed.

Its not the most advanced kit, I think it just monitors something basic, its only a standard 2014 2.0 sport A3

Thats the standard Audi system (as I said upthread, my ‘18 S3 uses it too) using the ABS sensors to count. If it’s going off every 2-3 weeks you’ve a leak somewhere. Adding an aftermarket TPMS system will give you real time readings and indicate well before the ABS based readings will trigger the car.

 

[CanadaA3wales]

Yeah I did look at those some time ago, but so many people are saying they fuse onto your wheels, so if they cant build them right with quality parts then I dont trust them to give proper readings. I know they have more expensive ones but they are like £100.00

I will go around my tyres today to see which one is the culprit, I will ask ATS to reseal it and go from there.

I was just wondering if these alarms go off even if it drops say 1 PSI, if so then I dont really need to be too concerned.

 

[rafletcher]

As I said, around 10 psi drop to activate on my A4 with 18” 45 profile tyres.

 

[CanadaA3wales]

Well it turned out it was the same wheel that the dead caliper was on, but was only 30psi and was supposed to be 35psi
All the other tyres were 34psi which was well within tolerance, but topped them up anyway.

Maybe it got triggered when the caliper and pads got replaced so have filled up and reset the MMI, will see what happens over a week or so.

If it goes down again on that one side I will ask ATS to reseal it, probably cost 10.00, if it goes down again then I will probably need a new tyre, even though I got some nice Primacy 4's all around 3000 miles ago.

 

[rafletcher]

Might just be a bit of debris or corrosion on the rim.

 

[Chris4410]

I wouldn’t call a 5 psi drop in 3 weeks normal, I would suspect a slow puncture or faulty valve.

 

[CanadaA3wales]

I didnt say 5psi was normal, I said the rest were 34psi so that was normal
I did get them fitted at ATS so may get them to have a look at it if its a faulty valve as they should have fitted this with my 4 new tyres.

Its nice that the MMI tells me which tyre was low so I knew where to look.

If its a slow leak is there anything I can do as the tyres cost me £100.00 each and have only done 2000miles.
Is there a spray I can put in the tyre to stop it leaking?

 

[JohnM100]

I didnt say 5psi was normal, I said the rest were 34psi so that was normal
I did get them fitted at ATS so may get them to have a look at it if its a faulty valve as they should have fitted this with my 4 new tyres.

Its nice that the MMI tells me which tyre was low so I knew where to look.

If its a slow leak is there anything I can do as the tyres cost me £100.00 each and have only done 2000miles.
Is there a spray I can put in the tyre to stop it leaking?

Tyler gunk - bad idea as it makes a mess

Slow leak - get it water tested.

Did you check pressures with a personal pressure monitor or rely on the notoriously inaccurate ones at garage & tyre fitters?

 

[AlS3BE]

If there’s nothing obvious like a nail/screw in the tyre it’s probably a bit of corrosion on the rim of the alloy where it beads to the tyre which does happen especially in a 6 year old car. If you think about it when you drive and corner the tyre moves a little on the wheel so in time the paint will wear through.
I’ve had it on 3-4 year old cars before. Couple of options if it’s corrosion is get a wire brush and smooth it out then use a liquid rubber solution as mentioned above or a full refurb so the rim is silky smooth to bead with a tyre.
To answer your original question, mine has only went off when I had a puncture in the tyre and no false alarms. Roughly drops about 1-2 psi all round every 6-8 weeks and that doesn’t set it off as all the tyres are losing pressure at the same rate.

 

[CanadaA3wales]

100% no corrosion they are all brand new refurb with powder coating, they are as smooth as a baby's bum lol

I have a cheap handheld one that got 5 star reviews on amazon from genuine sellers, it was only about £10.00, I then check it again after its filled up.
I have never had a dodgy petrol station air pump as they all seem to match my hand held device and have been to a few different petrol stations without a problem.

I will spray them with soap and water if they go down again. It could be due to the dodgy caliper and braking as my pads were shot to poo as the piston was stuck and it was on that wheel where it went down 5psi in a few weeks.

 

[Marler1337]

Only had it go off when I've had an actual leak. The tyre wasn't seated correctly on the alloy and so got it rotated and reseated. No warnings since touch wood!

 

[Flowrider99]

Why would a "dodgy" caliper cause a tyre to lose pressure? I would check the tyre and the valve.

 

[CanadaA3wales]

Why would a "dodgy" caliper cause a tyre to lose pressure? I would check the tyre and the valve.

Yeah I dont know LOL
If it goes down again I will do a water test, see where its coming from, lets hope its only a valve.

 

[Booti]

100% no corrosion they are all brand new refurb with powder coating, they are as smooth as a baby's bum lol

I have a cheap handheld one that got 5 star reviews on amazon from genuine sellers, it was only about £10.00, I then check it again after its filled up.
I have never had a dodgy petrol station air pump as they all seem to match my hand held device and have been to a few different petrol stations without a problem.

I will spray them with soap and water if they go down again. It could be due to the dodgy caliper and braking as my pads were shot to poo as the piston was stuck and it was on that wheel where it went down 5psi in a few weeks.

If the wheels have been powder coated recently, I’ll put money it’s leaking from the valve.
They don’t always get a good coating in the valve hole, this leads to corrosion and then the valve leaks. Only a little, but it’s enough.

 

[CanadaA3wales]

If the wheels have been powder coated recently, I’ll put money it’s leaking from the valve.
They don’t always get a good coating in the valve hole, this leads to corrosion and then the valve leaks. Only a little, but it’s enough.

That actually could be a good call as I had the new tyres put on before the powder coating, the powder coaters could have damaged the valve as well, but have no proof of this obviously.
Going to check the pressure on monday and if they are below 34psi I will take them back to ATS and see if they can reseal and fit a new valve.
Its only the rear drivers.
How much do you think a new valve and reseal would cost... Maybe £10.00 ??

 

[rafletcher]

Having mentioned upthread that mine never went off on my A4, today I got a low pressure warning for the right front on the way to work. Popped out at lunchtime, and found it was down to 25’ish, from 38 over about 4 months. No, I don’t regularly check the pressures.... The other front was 35, and the rears around 29 from 35. Quite surprised. Might now fit the pressure sensing caps for a “direct” pressure measurement (and make sure they don’t seize on!)

 

[S32B]

Having mentioned upthread that mine never went off on my A4, today I got a low pressure warning for the right front on the way to work. Popped out at lunchtime, and found it was down to 25’ish, from 38 over about 4 months. No, I don’t regularly check the pressures.... The other front was 35, and the rears around 29 from 35. Quite surprised. Might now fit the pressure sensing caps for a “direct” pressure measurement (and make sure they don’t seize on!)

On average tyres lose about 1-2 psi per month, add to the fact it's now colder at night which can also reduce your pressures!
I went out a few weeks back at 06.30 and noticed it was colder than usual, got in the car and the warning went off! Looked and couldn't see anything obvious, checked them all and they were all down to 30psi, came home that day and set them to what they should be...OK ever since (touch wood).