Ok so my tyres pressure light came on about 3 weeks after I bought my car so I checked and found the following:

Fns 18psi

Rns 22psi

Fos 27psi

Ros 22psi

Filled all up to 34psi.

At least once a week the light comes on the only noticeable tyre has been fns always dropping to around 16 - 20psi. Theres no visable defect or screw/nail in tyre, so I've just been topping it up till I can get it replaced. Only today I decided to check all four again and found:

Fns 19psi

Rns 25psi

Fos 27psi

Ros 24psi

Now obviously there's a significant loss in pressure all around but surely it's too much of a coincidence for all 4 losing so much, also tyres on front axle and rear are different so doubt they would have been fitted at the same time which leads me to doubt they've all got a poor seal at fitting. Wheels are unmarked no curbing either.

So my question.... Are the alloys known to crack or leak? Sorry for the essay but wanted to paint the full picture.

Probably leaky valves. Likely the last time the tyres were changed the old valves were put back on.

Ok so my tyres pressure light came on about 3 weeks after I bought my car so I checked and found the following:

Fns 18psi

Rns 22psi

Fos 27psi

Ros 22psi

Filled all up to 34psi.

At least once a week the light comes on the only noticeable tyre has been fns always dropping to around 16 - 20psi. Theres no visable defect or screw/nail in tyre, so I've just been topping it up till I can get it replaced. Only today I decided to check all four again and found:

Fns 19psi

Rns 25psi

Fos 27psi

Ros 24psi

Now obviously there's a significant loss in pressure all around but surely it's too much of a coincidence for all 4 losing so much, also tyres on front axle and rear are different so doubt they would have been fitted at the same time which leads me to doubt they've all got a poor seal at fitting. Wheels are unmarked no curbing either.

So my question.... Are the alloys known to crack or leak? Sorry for the essay but wanted to paint the full picture.

Limited Ed vRS alloys by any chance?

Standard pre-fl alloys.

The Zeniths are not known for corrosion but a number of other OEM Skoda alloys are, mainly the polished / diamond cut versions.

 

One of my Proteus alloys used to leak due to unseen corrosion that was on the inside of the rim.

 

My local tyre fitter used a special 'glue based sealant' and recommended I got the alloy refurbed as the glue was only a short term fix. This was 6 months ago and all has been well since. I'll get the alloy fixed when I need tyres, so in the next few weeks then

Are you using the same pressure gauge ? They can vary .

I have one that goes down to 20psi every month , as long as I remember to check it I'm not worried about it. 

I think its a small leak around the rim  

 

Who knows but it may be that the tyres were changed for winter tyres and then for summer tyres , Changing them around the wheels don't make for a good seal after being fitted twice or thrice.

The  early alloy wheels fitted to the triumph dolomite were swines for leaking as the coating inside the wheel where the tyre touched started to peel and crack and then started leaking air but I think any problems like that  will have been fixed now

 

The valves would have been changed as they are a great money spinner for the tyre firms, buy them for about thirty pence and sell for two pounds

I have a similar problem with one of my tyres.

Past experience has shown that when immersed in water and no means are evident, the tyre needs to come off and the alloy wheel cleaned up where the tyre bead seals.

Usually it's furred alloy and previous applications of tyre bead sealant.

A good rub with a bit of sand paper works wonders.

Corroded rims causing pressure loss?  Happens a lot - had it on my 100,000-mile Ocatvia with its original 15" rims.

Cured by removing tyres and cleaning up the rims.

Corroded rims causing pressure loss? Happens a lot - had it on my 100,000-mile Ocatvia with its original 15" rims.

Cured by removing tyres and cleaning up the rims.

Yeah I get this every time my van needs new tyres we have to grind of corrosion otherwise there is a really poor seal!

Yes same pressure gauge, seems like this corrosion of the rim could be the answer. I'm happy to just keep topping them up as there's no visable defects or anything to say their unroadworthy.

tyre/wheel assembly off, give them a clean & dump them in a swimming pool or bathtub (the tyre shop will have one).  You'll see the bubbles soon enough

Do all tyre shops in Australia have swimming pools ?

 

Cant imagine it happening here ," Just nipped along to kwik fit and had a splash in their pool while waiting for a puncture repaired ."

 

Yeah I get this every time my van needs new tyres we have to grind of corrosion otherwise there is a really poor seal!

.

Does give yet another reason to have your winter tyres on a  different set of rims, if you can afford it.

Then, unless you damage a tyre, the tyres can stay on the rims undisturbed until they are worn out.  It also means that you can quickly and easily change between winter and summer tyres any time you want, and at no cost.

(I am still waiting for MyTyres to respond to an email before I buy - at what seems a very reasonable price - a set of summer tyres complate with new alloy rims.) 

 

tyre/wheel assembly off, give them a clean & dump them in a swimming pool or bathtub (the tyre shop will have one).  You'll see the bubbles soon enough

Swimming pool at the parents  - and yes I've bubble tested tyres at their house.  Dad not impressed.   You have to wash all the brake dust off first

One of my tyres/wheels continually loses pressure, I might ask at the local swimming baths if they'll let me take them into the pool with me!

Found the cause of my small leak , air escaping between the valve body and hole in the wheel . Must be corroded in there or a piece of **** trapped in it.

_{Mix up some soapy water and paint it round the wheel rims and valves. It will let you see where the leak is.}

Considering just getting new alloys and swapping over the tyres. Seen a set I like at a decent price so that's looking favourite.

Have a similar problem with NSR alloy. National Tyres advised rim is slightly corroded inside and have applied a sealant....but makes my argument for a full refurb of alloys even more plausible now