Slow Puncture - tyre or valve?

[bompey]

Hi,

I'm just after other views on what to do next. I am slowly losing air from one of my rear tyres which I took to my dealer to replace. They couldnt see any problem with the tyre and suggested to keep driving in case someone had just let my tyre down. A few weeks later it seems it is losing air but the tyre looked ok to the dealer.
Do I replace the tyre anyway, or is the issue likely to be with the valve, in which can I just get the valve changed, or should I do tyre and valve? And if the tyres had worn out I would have preferred to change brand from Pirelli P zeros to Michelin.

FWIW the car is a Boxster 981 and I am planning a summer road tour to Italy. Your thoughts please?

Thanks

[paintman]

Fully immerse it in a container of water & look for bubbles.

[Davie]

Could be the tyre has a puncture, could be the valve seat, the valve core, the bead, a fracture in the rim... I'd take it to a reputable tyre fitter who'll likely find the source of the leak. Or take it off yourself, dunk it under water... and wait for the bubbles

[Pebbles167]

Possible crack in the wheel? Although it's likely that would have been checked by a dealer and spotted if there, I wouldn't always bet on it.

[rallycross]

Take it to a small Tyre shop they will tell you in 5 mins what the problem is and fix it for £15.

[stevemcs]

Could be anything, the sidewall, rim leak, valve … it may even need the tyre taking off and looking inside.

You could start by spraying some soapy water around the valve - take the cap off too just in case it’s the valve core.

[trickywoo]

The wheel itself could be porous.

[ScoobyChris]

I have similar on one of my summer tyres. Tyre had a puncture which was repaired, but every 3-4 days triggered the TPMS. The alloy had seen better days and a new one came up on eBay so had a tyre guy come out to move the tyre to the new wheel. Mentioned the slow leak and he said everything looked fine but redid the puncture repair and tested the tyre and was happy there was no leak. 4 days later TPMS goes off 🤬

Given the tyre has 6mm of tread on it, I’m currently living with topping it up once a week, but next time I have the tyre guy out I will mention it again!

Chris

[Zarco]

I've got the same problem. Couple of weeks ago noticed my rear tyre was losing 0.5bar over night. Assumed I had a puncture and went to a tyre shop. They told me it was the tyre bead that was leaking, rather than a puncture. They took the tyre off, cleaned up the inside/bead, and sent me on way free of charge.

Unfortunately it didn't fix it, although it is slightly better. Four days ago the front tyre started doing the same thing!

The likely cause is the surface of the alloys has started to deteriorate. Only sure fix seems to be a refurb.

[996TT02]

Lots of good advice here, but to sum up - you find the problem and fix it. If you replace the tyre and the rim is the problem, leaking bead due to very light corrosion is incredibly common, you will still have the leak, guaranteed.

If a big enough bath is not available and you want to find out for yourself, use soapy water and a brush. Be aware that bead leaks are often incredibly slow but from multiple locations, so get the wheel off and laying flat, brush on soapy water and wait 10 minutes, the bubbles will be miniscule but a foam will have developed at the leak. Check both sides. If confirmed, the tyre is removed and the rim is sanded all round where the bead seats, a dash of well dried rattle can paint is advisable.

[Scrump]

rallycross said:

Take it to a small Tyre shop they will tell you in 5 mins what the problem is and fix it for £15.

This, although may be a bit more than £15.

[Geffg]

Got the same with my front tyre. Sets the tpms off every few weeks but I’ve had it in the tyre place who was unable to find anything. Just persevering with it for now

[Mave]

Wheel rim corrosion is pretty common. I've needed to refurbish many wheels over the years just to get them to hold pressure.

[sociopath]

Stick it in your bath.

Don't do it while the better half is around

[T1berious]

A half decent tyre place will have a large container that they can place a wheel in and trace a puncture. That's how I discovered the clowns that did my wheel refurbishment mangled the valve...

[Chris32345]

Take it to a proper tyre place and not a main dealer?

[MakaveliX]

Similar thing here. I check me tyre pressures weekly and the only one which tends to go down slightly faster than the rest is the one which has been plugged. Seems to lose about 2PSI per month or so.


Had PS5's fitted all round 4 months ago then one week later got a puncture

[bompey]

Thanks all. Looks like local friendly tyre shop is my next stop.

[bompey]

By way of update I took the car to a local tyre specialist who took a look and whipped off the wheel. They found a nail embedded which the dealer had missed. Quick repair and all good now.