Tyre Pressures

[Shutpa]

Although I shouldn't really admit it, I have always been lax at maintaining my car which I change for new, every couple of years. I have never ever checked the oil levels or the windscreen wash and have only checked the tyre pressure on the rare occasion. However, when the car, a year old Mazda 2 started started to sort of skid when cornering a few months back, I checked the tyres and found that they were well down. Now all 4 tyres lose about 2psi every week. What causes this and can it be rectified?

 

[Burnerman]

You may have alloy wheels.....?
If so, slight corrosion occurs where the tyre meets the rim, and this causes a slight air leak.
Your tyre fitter should rub this corrosion away when new tyres are fitted.
If all else fails, a tyre sealant 'mousse' is injected through the valves, which effectively does the same job.
Mind you, at a year old this is fairly unusual...it could be worth asking Mr. Mazda if they are having issues with these wheels.
John

 

[Shutpa]

You may have alloy wheels.....? No.

If so, slight corrosion occurs where the tyre meets the rim, and this causes a slight air leak. If there is, I cant see it.

Mind you, at a year old this is fairly unusual...it could be worth asking Mr. Mazda if they are having issues with these wheels.
John

Thanks for the quick reply. I never gave your last point a thought before you replied, but have now booked the car in on Thursday to have the wheels and tyres checked over. Guy said it could be faulty valves.

 

[Burnerman]

Well.....it could be - but all 4 valves faulty? The time honoured method of a wee bit of spit over the valve stem is the thing to do.
I presume these are your original tyres and wheels - to be honest, its only the alloy ones that have leakage issues, and only losing 2 psi per week the leak would be very slight and hardly noticable.
Its good to see that tyre fitters seem to use the white tyre lube solution when fitting tyres these days - they didn't always do that.
I've never seen a recall to deal with leaky steel rims, but its quite common with corroded alloy ones.
John

 

[Shutpa]

The time honoured method of a wee bit of spit over the valve stem is the thing to do. ???????????

I presume these are your original tyres and wheels ..They are.

Only losing 2 psi per week the leak would be very slight and hardly noticable...it's very noticable when the car slides round corners.
John

Thanks once again for your reply. What I cant understand is that I have never had this problem before and this is my 23rd car. Perhaps there was a whole batch of valves faulty. By a "wee bit spit" do you mean on the air thing that the screw-on cap goes on?

 

[Burnerman]

A dab of spit over the valve (below the screw on cap) is a sure way of finding out if the valve is leaking, but its highly unllikely that all 4 are faulty! This of course will not check for leaks between the valve and the rim or tyre and the rim - this can only be done by submerging the wheel and looking for bubbles.
You wouldn't notice any difference if the tyre pressures were a couple of pounds out either way, but it is a good idea to check them once in a while!
John

 

[Shutpa]

Cheers mate, in future I will check!