All 4 tyres of my car seem to be losing pressure slowly. Why?
 

Every few months I get the warning light to check my tyre pressures. So today, after getting the warning again, I decided to record the current pressure of each tyre so I could confirm which one it was. However when it came to adding air to them all of them where several (5-7) psi off where they should be and none dramatically worse than the others.

I doubt I have a slow puncture on every single tyre. They're not even that old. The tread is fine on them all. The car passed a full MOT and Service back in July.

Any ideas? :confused:

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

Have you alloy wheels?
Leakage from the rims.

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

^^

Seconded. Leakage from the rims. Cure is to have the tyres removed and the rims cleaned up. Your local tyre specialist can advise.

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

Mmmm cheers. I'll take it to a tyre shop and see what they say.

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

Thirded. I had all 4 alloy wheels stripped and recoated locally for under £200 last year. I've checked the pressures weekly and have not had to reinflate them at all since then.

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

Another option is to fill with nitrogen, the molecules are thicker the O2 ones, leak less

People at work fill their tyres with nitrogen.

The joys of filling plane tyres.

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

You could lose a bit of weight to balance it out. :shrug: :jk: :)

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

Or put more on. :D

---------- Post added at 19:11 ---------- Previous post was at 19:11 ----------

Why would all 4 be dodgy though?

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

How old is the car?

Alloys do corrode especially if you clip the curb, stone chips etc.

Another thing could be valves are knackered.

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

1995 car, corrosion on all 4 rims where some daft pi11ock used knock-on balancing weights instead of stick-ons before I bought the car in 2000.

The valves were all changed (as per the norm I think) when the tyres were changed.

---------- Post added at 20:05 ---------- Previous post was at 20:03 ----------

My old Lada wheels drove mechanics to distraction as they just kept on slowly deflating. Then they found out why: the wheels were made of 2 castings joined back-to-back, with a thin rubber gasket between them. And Russian rubber doesn't last long.

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

That figures :rofl:

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

Car was used as the getaway vehicle and ran over a stinger

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

I had the alloy coroision / tyre pressure issue with an old car. Kept gradually reoccurring even though I kept getting it sorted at the garage.

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

Many tyre fitters will try applying a black, gooey gunk to the rims before refitting tyres. Sometimes it works, often it doesn't.

Re: All 4 tyres of my car seem to be losing pressure slowly. Why?
 

Most alloy wheels, even silver ones, have a painted finish. Problems start when that paint is chipped, such as kerbing the rim or using clip-on weights. Corrosion then sneaks in under the paint often forming a path to the inside to allow a slow air leak.

Whilst a clean up of the tyre bead seating area and some goo will often provide a short term solution, the only real answer is to have the rims stripped, cleaned and re-painted.