Mysterious tyre pressure loss

[Louie]

Now i dont want to be paranoid but a couple of weeks ago i noticed the tyre pressure warning sign came up on the dash i ignored it attributing the loss to accidentally mounting a curb with my rear offside wheel at low speed. Imagine my surprise when i called on one of these automatic tyre filling stations where you put in a pound set the pressure you want and it beeps when the required pressure is reached so fronts were down to 28 (33) and rear to 26 (30).  After filling tyres the on screen warning symbol vanished. I normally keep a close eye on my tyres but have never experienced loss of tyre pressure in all four Michelin Pilot 4 's before, having used them for the past 6 years without any problems. The question here is if the car remains unused more than normal and in cold weather are tyre pressures affected ?

 

 

[john p williams]

51 minutes ago, Louie said:

Now i dont want to be paranoid but a couple of weeks ago i noticed the tyre pressure warning sign came up on the dash i ignored it attributing the loss to accidentally mounting a curb with my rear offside wheel at low speed. Imagine my surprise when i called on one of these automatic tyre filling stations where you put in a pound set the pressure you want and it beeps when the required pressure is reached so fronts were down to 28 (33) and rear to 26 (30).  After filling tyres the on screen warning symbol vanished. I normally keep a close eye on my tyres but have never experienced loss of tyre pressure in all four Michelin Pilot 4 's before, having used them for the past 6 years without any problems. The question here is if the car remains unused more than normal and in cold weather are tyre pressures affected ?

Yes

[flash22]

Oh yes, air gets denser the colder the temp add in the moisture content 6-8 c drop - drops the pressure by 1psi (ish)

[AndrueC]

I got an alert coming back from golf on Sunday. Wasn't surprised since the car is normally kept in a garage and it hadn't been used for over a week. It's a shame that the alarm doesn't give more details but I checked the tyres and they'd all dropped by more or less the same amount of 3psi.

I've restored the pressures so I'll probably get another warning when the weather warms back up.

[King Crimson]

Exact same thing happend to me last year, this is my first car with a tyre pressure warning so i was worried when i saw at first but i found out it's because of the lower temperatures. It came up again a week ago but we're in lockdown right now and i haven't bothered to fix the issue yet.

[King Crimson]

Just now, AndrueC said:

 It's a shame that the alarm doesn't give more details but I checked the tyres and they'd all dropped by more or less the same amount of 3psi.

Yea i was thinking of that too, i don't understand why they wouldn't do that since in order for the system to work each tyre has to be monitored, right? Should be pretty easy to show on the dash which tyre is losing pressure especially since most corollas come with the bigger digital screen.

[bigblock]

This is why tyre pressures are supposed to be set when tyres are cold. If pressure was set when tyre was warm then you would notice quite a drop in pressure in these cold temps we have at the moment. Hence the pressure monitor warning activating. I agree that it would be nice to know which tyre is causing the problem.

[Rambler56]

As mentioned in a previous thread.  The sensors can be a tad sensitive so can trip for very small variations in pressure (cold weather in the main). The suggestion put forward, to overcome any 'false warnings' was to inflate the tyres to 2psi below requirement when cold, reset TPMS, then inflate to the correct setting.  

[Timmon]

The low profile tyres are very prone to this, because of the lower volume of air compared to standard tyres. It is a pain, but it is right that the alert goes off, because low profile tyres should be checked for correct pressure more often.

[Louie]

Hi Guys  yes thank you for all your comments but I have had the same make of low profile tyres on VW's,  Honda's and  Toyota's in the past without this palava of loosing tyre pressures and  having them all  go down when its cold etc. The vehicles have always been parked outside so what has changed methinks the arrival of complex technology, change in tyre compound composition, climate change, take your pick. I now have my own personal tyre gauge in the form of "her indoors" who  can always tell if there has been any loss in tyre pressure because she claims the car handles differently especially when cornering and she suffers from ear balance problems how weird is that.

[flash22]

That's a common thing - you can feel the pressure drop in the tyres on a FWD you can feel the rear is a little looser and the steering becomes heavier 1.5 - 2 psi drops is all it takes - you get a feel for a car after a time

 

I have a mechanical tire gauge to check the pressures

https://www.ebay.co.uk/itm/RACE-X-PROFESSIONAL-TYRE-PRESSURE-GAUGE-CASE-RX0014/164179206136?epid=11034904852&hash=item2639d7dff8:g:0bAAAOSwT-FZAcHj

[FROSTYBALLS]

I have three of these - https://www.drapertools.com/product/69924/Tyre-Pressure-Gauge-with-Flexible-Hose