Tyre advice pls - one rim + tyre deflating faster than others

[Werewolf1976]

Hi all

 

Hope you're well - I have a gs250 that I bought used

The tyres lose air pressure in a uniform way except one -- looking for advice on how to test / fix

Context
1) The tyres I inflate to 36.5 psi and over two weeks in London - 3 deflate to c32psi and 1 rim deflates to 25 to 24 psi
2) I had Lexus Edgeware check the rims about a 1 yr ago and they said they could find no bends / cracks on the rims or issues in the tyres
3) I had them rebead and reseat the troublesome rim - it still deflates faster
4) About two months I had a local garage - rebead the rim again and now the problem persists

At a loss as to how to diagnose or fix the issue - any advice much appreciated!!

Thnx!

[LenT]

You say Lexus Edgware could find no issues with the tyres, but I wonder if you have a problem with the valve?

If you have a dust cap on it, for example, any grit in the cap could be depressing the valve.  Or the valve could be leaking anyway.

Put the valve at the bottom of the wheel and try gently pouring water over it, looking for bubbles.

Incidentally, you don’t mention the age of the tyres.  They do deteriorate with age irrespective of mileage.  Here’s how to check the age of a tyre.

• Check the sidewall for the letters DOT.
• Next to this, there’ll be a 4 digit number code.
• The first pair of numbers is the week of manufacture.
• The second pair of numbers is the year of manufacture.

For example, 0720 means the 7th week of 2020.

Hope this helps!

 

[scudney]

Possible slow puncture 🤔

[J Henderson]

I'd say all 4 wheels are an issue if they're losing 4 or 5 psi within 2 weeks. That's a bit above what I'd consider normal.

Just to add to Len's tip re: pouring water over the tyre & valve to check for leaks. Adding a drop of washing up liquid to the solution will make bubbles more likely to appear, or be more visible.

[steve2006]

As above, check the valve and check for punctures in the tyres.

What condition are your wheels in?

The usual Lexus quality normal results in flaking paint preceding corrosion of the alloy, if the paint has lifted around the rim beading air can escape under the paint even with sealant applied if it is not thoroughly cleaned up before application.

A weekly pressure check may be the short term action.

[Malc]

2 hours ago, steve2006 said:

thoroughly cleaned up before application.

I had an interminable issue with one tyre a couple of years or more back ..... a thorough " scrubbing " to remove the crap flaking rusting stuff etc  by the tyre place sorted that wheel properly and it's only 2+ years later that the same tyre began to " leak "  /// offside rear actually ......  could that be generally prone maybe ? or possibly the tyre now , it's the same one and been there for a few years but looks ok  ......  of course not covered too many miles these past 2 years or so with covid and stuff

Malc

[rayaans]

2 hours ago, steve2006 said:

As above, check the valve and check for punctures in the tyres.

What condition are your wheels in?

The usual Lexus quality normal results in flaking paint preceding corrosion of the alloy, if the paint has lifted around the rim beading air can escape under the paint even with sealant applied if it is not thoroughly cleaned up before application.

A weekly pressure check may be the short term action.

The modern Lexus wheels dont suffer from the same problems as the older ones

The 4th gen GS certainly had no issues with the wheels. 

Id say likely puncture, valves or the tyres themselves. What brand are they?

[steve2006]

Wasn’t there reports of the wheels going porous?

[Werewolf1976]

Hi all, 

 

Testing the valve - no issues

The tyres are 3719 or the 37th week of 2019 I believe

Stumped...

[Werewolf1976]

I dont drive the car much...what do you think of the following

1) buy a full-sized used wheel + tyre from eBay (like 200 quid) - this way I get a full-sized spare

2) simply swap the tyre to a new one and hope for the best

[PRT68]

Looking from another angle. The 3 tyres all losing the same amount of pressure could be explained by the temperature and conditions not being the same when the second reading is taken. Warm tyres will give a higher pressure, cold tyres a lower pressure.

That's why pressures are reduced on track days etc.

As for the odd one losing pressure, get the tyre swapped over to one of the other rims. You should then get an indication as to whether you have a porous rim or slow puncture. 

[Spock66]

Do you have TPMS valves, the metal body tends to corrode with the wheel (Galvanic corrosion I believe) and this can cause a slow leak. 

[Werewolf1976]

Good points

Assume that I am a cheap person, the TPMS needs to be reprogrammed?

i.e. what is the most cost effective way to solve the problem you think?

[Malc]

1 hour ago, Werewolf1976 said:

the TPMS

does a 2012 car need the TPMS to be fully functioning for the MOT ?

Malc

[J Henderson]

November 1, 2012 is when it became a legal requirement.

[Spock66]

1 hour ago, Werewolf1976 said:

Assume that I am a cheap person, the TPMS needs to be reprogrammed?

You can get repair kits if the actual sensor is still functioning.

[Sherra]

I would suggest that changing the rear tyres rim to rim to eliminate or prove porous rim would be the cheapest next move then take it from there armed with the results. TPMS does not require any recoding.

[Werewolf1976]

Hi all, went to get a MOT done and its a leaking/rusty TPMS sensor

Thanks for all the advice!  

Anybody know where I can get an OEM part cheap cheap?  

Many thanks!

 

[KayCee]

a local tyre place will have the TPMS body just a few quid

[Werewolf1976]

2 hours ago, KayCee said:

a local tyre place will have the TPMS body just a few quid

I did ask and he told me to get an OEM part - will report back

Old cars and their needs...

[LenT]

1 hour ago, Werewolf1976 said:

I did ask and he told me to get an OEM part - will report back

Old cars and their needs...

This may not be something you want to consider, John, but there’s always a possibility that the other valves - being of similar age. I expect  - may also be developing the same problem.

In any case, the batteries in TPMS valves are generally considered to have a useable life of up to ten years.  You don’t mention the state of the tyres, but are they also approaching the point of replacement?

Of course much depends on how long you propose to keep the car and how much you’re prepared to spend on it.  But it may be worth considering that, for example, you can negotiate a good deal on a new tyre AND valve as a combined purchase - but if you have to replace the valves later one by one, you’re also paying to have the tyre removed and replaced every time.

[Werewolf1976]

59 minutes ago, LenT said:

This may not be something you want to consider, John, but there’s always a possibility that the other valves - being of similar age. I expect  - may also be developing the same problem.

In any case, the batteries in TPMS valves are generally considered to have a useable life of up to ten years.  You don’t mention the state of the tyres, but are they also approaching the point of replacement?

Of course much depends on how long you propose to keep the car and how much you’re prepared to spend on it.  But it may be worth considering that, for example, you can negotiate a good deal on a new tyre AND valve as a combined purchase - but if you have to replace the valves later one by one, you’re also paying to have the tyre removed and replaced every time.

all fair - the tyres are newish like 2-3 yrs old with less than 20k - good tread

Next time I am in the US I will pick up more TPMS pre-emptively

My local charges 20 quid to re-rim and bead / check the tyre

Death by a thousand small services

[KayCee]

John

The TPMS in US use a different Frequency to oura so will be no good

 

[Werewolf1976]

OOF

[steve2006]

Amayama don’t supply these to the UK for some reason.

LPD price below.