Wheel/tyre losing 5-7psi in week: wheel or tyre to blame?

[RoVoFob]

I picked up a 54-plate S60 T5 10 days back and it looks like the tyres are losing around 5-7psi over the course of a week. The rears had 12-15psi in when I topped them up immediately after I bought it (they didn’t look anywhere near that low...) and since topping them up, all four have dropped a reasonable amount in a week.

I had a 56-plate V70 with identical alloys until a month back and that barely seemed to lose any air - both with the ancient, very worn tyres on it when I bought it and the Michelin PS4s I had fitted.

The S60 has three Michelin Cross Climates and a Continental on it, but I think one of them was manufactured in 2013 and the other 2015 (I couldn’t find any date stamps on the other two...), so I wonder whether the rubber is particularly degraded.

Is it most likely that the rubber is simply knackered, or would you expect the alloys to be part of the problem for that scale of air loss?

Thanks.

[RoVoFob]

donkmeister said:

I've had that happen due to corrosion on the wheels where the bead of the tyre sits.

Solutions are:
1) Replace the wheels
2) Refurb the existing wheels
3) Ask the tyre guy to sort it, and he'll use a die grinder to clean up the surface and use goop to seal the bead.
4) Fill your tyres every day and hope.

Those are in order of best-worst, and most expensive-least expensive.

How corroded were your wheels? The odd thing is that the wheels look in pretty good nick. Better than the ones on the V70...

[RoVoFob]

fatboy b said:

Tweak the valve up. I’ve had this numerous times.

Screw the whole thing in further?

[RoVoFob]

donkmeister said:

On appearance, not very - could definitely see a bit of bubbliness in the paint/coating around the rim before the tyre was removed, but the wheels had a fair bit of kerbing.

MIght be worth a google to see if it's a regular issue with those particular wheels too - we had a Mazda MX5 S-VT and the wheels on those are prone to the coating peeling off and airloss occurring. Something due to the powder/paint process being implemented incorrectly.

Valves are another possibility (as posted by another). Unusual to have all four go but I could say the same about corrosion too!

Hmm. I’m planning to change all four tyres, so I can remove that variable. I just don’t want to change them and find the tyres still losing air at the same rate, as I don’t think it’s great to take the same tyres on and off the wheels multiple times.

These wheels have notably less kerbing than the previous set. No MOT flags of distortion, either, which I did had on one of the wheels on my old V70. Even that didn’t seem to lose air, though. Odd.

I’ll do some wheel-specific searching, but don’t remember seeing anything before. Thanks.

[RoVoFob]

TGTiff said:

I had something similar on the nearside front, would loose a couple of psi a week. Turned out to be a very fine crack right on the edge of the rim of the alloy.

How visible was this?

[RoVoFob]

fatboy b said:

It’s always the first thing I do after getting new tyres. Been caught out numerous times. Just nip them up a bit. I’d be surprised if all 4 wheels are cracked. Needs a valve tool though.

Will pick myself up a valve tool. Checked the tyres again today and think they’d only lost 2-3psi in the last six days.

One of the rears had air gushing out as soon as I went near it with the pump, so potentially that valve is overly loose...

[RoVoFob]

BigR said:

Can be a buckled wheel, which can be fixed cheaply. But if its happening to all 4, that sounds somewhat unlikely.

I had a buckled wheel on my V70 with identical alloys. That was flagged in several MOTs and didn’t lose air. There’s no record of a buckled wheel on this S60, so think that’s unlikely here - especially, as you said, it affects more than one of the wheels.

My money’s on iffy valves for now. Will pick up a valve tool later.

[RoVoFob]

remould said:

This may sound like a micky take,but it's not,have you got valve caps and are they in good nick ?, no valve caps is another reason for loosing pressure

The current tyres don’t have valve caps, but I wouldn’t have thought they prefer the valves losing air...they just protect the valves from damage, don’t they?