Warning lights after MOT

Lau03

I had my car MOT’d and serviced yesterday. There was a fault to one of my tyres which was bulging as a result of some damage to the alloy on the inside. They have put a new tyre on the car and told me they would try to re-shape the alloy to seal it better. On driving the car home last night the tyre pressure warning light came on. Does the damage to the alloy cause tyre pressure to go down? Don’t really want to take it back to the same garage as they were very pushy but looking for some advice of what to do?

wongataa

If the damage to the wheel prevents the tyre sealing properly on the wheel, then yes it can very easily let the air out of the tyre.

AdrianC

You say the TPMS light is on - but not whether you've actually checked the pressure?

It may be that it's simply not sealing properly, so a slow leak.
It may be that the pressure sensor needs replacing after the tyre's been replaced, or is not communicating for some reason.

But if the wheel is damaged so the tyre doesn't seal, then replacing the tyre seems to be the wrong answer... I assume the old tyre was also damaged.

Oh, and btw, "MOT and service" is irrelevant to this, unless you think they're the only reason for having damaged wheels and tyres sorted...

Lau03

I have tried re-setting the TPMS light as usual and I have checked the tyre pressure which is only very slightly down on what it should be.
Yes the old tyre was also damaged- there was a bulge on the inside that you couldn’t see without them lifting the car up. So I’m thinking then that the alloy may need replacing too?

chrisw

It appears you have hit something like a large pothole which has damaged the wheel and tyre.

It also appears that the garage have done their best to minimise the cost to you by replacing the tyre and trying to repair the wheel.

Unfortunately their fix does not seem to have worked, either because the wheel is not quite straight or the tyre isn't seated properly, which can happen occasionally even without any damage.

The garage seems to be reasonable, take it back to them. They will either reseal the tyre, adjust the repair or advise that a new wheel is required.