[CarHelp]

Hi,

Newbie here sorry if this is in the wrong place.

I need some serious help before I have a mental breakdown!

I'm going to start by saying I know nothing about cars.

My tyre pressure light has been coming on for weeks. I have had 3 new tyres. It came on again earlier this week so I popped into Kwik Fit on the way home from work and they said tyre seemed fine but they could see a dink in the alloy which could cause air to escape - they recommended a local garage to me.

Go to the local wheel repair garage the next day and they can't find the dink... they apparently checked all tyres for cracks etc and also apparently checked rhe valves for air leaks - nothing. I asked what could be causing it and he said something about corrosion (it's a 2021 car, could it have corrosion??) And said they could refurb something on the alloys(?) So I had all 4 wheels done to put my mind at rest (this was Wednesday).

Today (Friday) the God damn pressure light comes on AGAIN! I go straight to a BP garage to check the pressures. Driver side is fine, the passenger front side tyre was 19, down from 33 and the rear was a nightmare to get a reading from, it said 18, then 11 then 26 and I couldn't get it up to 33.

What's going on?!

I don't know what more I can do/try, I am at my wits end and am getting close to selling the thing because it's driving me mad. I have tried all I can try.

Is it the machine, is it the car, is it something else.

Please, if anyone has any advice, I would be very appreciative.

Thank you!

[NMNeil]

It sounds like the tyre that is giving erratic readings may be the sensor inside the wheel, but the actual pressure dropping is obviously a leak somewhere.
The old school way of finding leaks was to inflate the tyre to around 50 or 60 psi and put it in water and watch for the bubbles. Can be awkward if you don't have anything big enough to submerge sections of the tyre or dont want to use the bathtub. Alternatively a spray bottle with water and dishsoap can be used to spray water around any areas that might leak, such as the valve stem, and again watch for the bubbles.
Whatever you do drop the pressure back to 33 after you finish.

[CarHelp]

Originally Posted by NMNeil

It sounds like the tyre that is giving erratic readings may be the sensor inside the wheel, but the actual pressure dropping is obviously a leak somewhere.
The old school way of finding leaks was to inflate the tyre to around 50 or 60 psi and put it in water and watch for the bubbles. Can be awkward if you don't have anything big enough to submerge sections of the tyre or dont want to use the bathtub. Alternatively a spray bottle with water and dishsoap can be used to spray water around any areas that might leak, such as the valve stem, and again watch for the bubbles.
Whatever you do drop the pressure back to 33 after you finish.

Hi Neil

Thank you for responding. Since posting, I took my car to Protyre on Saturday, it was there all day - they had the 2 passenger side tyres in baths for 2 hrs and couldn't see any leaks. After leaving about 15 mins down the road, the bloomin light comes on again - I check the pressures and one of them is down 10psi! But the garage apparently couldn't find an issue.

I would try doing it at home, but unless I lug the tyre into my bath, I don't think I have anything big enough to put it in, I did try the spray bottle and nothing happened, not sure if that's because there is no leak or if I was doing it wrong.

Yesterday I went to Kwik Fit (they fitted one of the tyres in April) and they gave me a other new one for free. Pumped everything up to 34 and after 6hrs (of no driving) the rear passenger had dropped to 32. I pumped it back up to 34 at about 9pm last night and it had dropped back down to 32 this morning - does that seem normal? I know it's not as big of a drop as 10, but even to go down 2psi in the space of 6hrs seems excessive?

I can't get it booked in with the dealership until 4th June!! So have booked it into another car garage (all the others have been tyre only places) to see if they can do any diagnostics and check the sensors etc.

😫

[Drivingforfun]

To clarify did this start happening after getting the new tyres?

Aside from above ideas… stupidest suggestion I have, but these days wouldn’t surprise me, is the original tyre place didn’t seal the new tyres on properly when they changed them

[CarHelp]

Originally Posted by Drivingforfun

To clarify did this start happening after getting the new tyres?

Aside from above ideas… stupidest suggestion I have, but these days wouldn’t surprise me, is the original tyre place didn’t seal the new tyres on properly when they changed them

Hey, thank you for the reply. Its a bit long but it started just before Easter, and it seemed to be 1 tyre per week going down (3/4 of them) I had them all changed staggered (as and when they went down) - it was 2 on the passenger side and 1 on the drivers side. Drivers side is currently fine, it's the passenger side that's a problem although the rear one seems to be going down faster. Since posting I have been back to Kwik Fit who fitted the rear passenger tyre and they replaced, they definitely over sealed it this time as I have all the gunk on my alloy now 🤔

[Rolebama]

It seems very erratic. Are you sure someone isn't playing silly games when your car is parked up?

[Beelzebub]

OP
Apart from anything else, fitting new tyre(s) would almost certainly cause erratic results from the TPMS - every system I've had needed re-setting in those circumstances. You need to read the manual.

[CarHelp]

Originally Posted by Rolebama

It seems very erratic. Are you sure someone isn't playing silly games when your car is parked up?

This did cross my mind- I have CCTV at home on my car and nothing is showing, also have cameras at work and apparently nothing is showing on there 😫

[CarHelp]

Originally Posted by Beelzebub

OP
Apart from anything else, fitting new tyre(s) would almost certainly cause erratic results from the TPMS - every system I've had needed re-setting in those circumstances. You need to read the manual.

Thank you - yes I have reset each time I have had a new tyre fitted.

[NMNeil]

@CarHelp Let us know how you get on because there is one last desperate thing to try if all else fails.
Deflate tyre, remove schrader valve, using a syringe put some UV dye into the tyre, replace scharder valve and inflate. Drive a few miles then check it with a black light especially around the valve and valve stem.
https://www.ebay.co.uk/itm/230723938073
Not meant for tyres but both tyres and radiator hoses are rubber so there should be no problem with compatibility.
I've used dye many times to find mystery leaks in AC systems and it worked every time.

[olduser]

To the best of my knowledge tyres are not put on with a sealant, they are put on with a lubricant.
The area on the wheel where the tyre sits and seals needs to be clean but usually it has been protected by the tyre removed, and it is part of tyre fitting to do a quick visual check, if for no better reason than the customer will come back if it is leaking, and refitting takes time and time = money.

Checking valves for leaks needs to be done with the valve cap removed, water and detergent works fine for testing.

On car tyre pressure indicators are OK for indicating soft or hard but beyond that I would never trust them.

Pressure gauges on garage/fuel station air lines have a tough life so I would never accuse them of being accurate.

I use my own simple pressure gauge, nothing clever just a simple tyre pressure gauge.
Tyres pressure will vary, tyre hot = pressure high, cold = low.
The car hand book tyre pressure data assumes the tyre is cold, meaning check pressure after car has been unused for a couple of hours or more.

If I have to inflate tyres at a public air line, I will check them later when they have cooled, they must have got warm driving there.
Otherwise the norm is to check and inflate tyres (foot pump, then I got lazy electric pump) at home with cold tyres.

If you are already doing all of this, and because you are suggesting it is differing wheels, think long and hard about who is letting them down.

[TyreRunner]

@CarHelp If it’s still losing pressure after a reseal, it could be something small like a valve issue or corrosion where the tyre meets the rim — even newer cars can get that. We’ve put together a quick guide that might help narrow it down: 8 common reasons for tyre slow leaks. Hope it helps before you end up back at the garage again.

[CarHelp]

Hi Everyone

Thank you for your input.

So I had the passenger rear replaced Sunday, pumped them up to 34 monday morning, tyre pressure light came on yesterday and rear passenger was 32.

Front passenger was 28. I have just had a call from the garage and they found a leak on the front passenger valve so they have replaced it. Which is interesting as one of the garages said I could try replacing them, although there aren't any leaks but would need to get them direct from Hyundai .. which I thought at the time was strange, obviously not the case if the garage today have replaced it there and then!

They checked all other tyres, valves etc and cant find any issues.

Hopefully this finally sorts the issue!

Can't believe it has taken 4 garages to get to this point. They all said they checked the valves - 1 even accused me of lying.

Will be a huge relief if this sorts the issue.
Hopefully having the rear passenger one replaced on Sunday sorted that one too.

Will let you know if the damn light comes on again.

Also, @Olduser I have noted about the tyre pressure things and will use the one that come woth the car rather than a petrol station machine.