I have Rainsport 2's on the front of my Fabia VRS. I have problems with both of them letting air out and loosing 15 PSI a week. I have had them both checked by two professional garages and both of them has said that there is no puncture and it is unexplained.

I have standard alloys on.

Anyone else has these problems?

Dodgy valves?

I have the same tyres on the front, my rear was loosing air - get the alloy checked for leaks will take two mins pour water round the rim look for bubbles

Yes, the alloys could well be corroded inside the valve hole. I had this and it gave me a fairly bad slow leak.

If a puncture has been ruled out then it could be a faulty valve, corroded rims or cracked rims. Here's hoping it's just faulty valves

Thanks for all the replys everyone but one of the tyre factories submersed it into water and we both watched it for around 10 mins and no bubbles came out of the tyre. He made sure the tyre was pumped up before. Would it only leak with the pressure of the car on it?

Allow wheel corrosion without a doubt.!!

Tyre & valve stem removal for intensive wheel cleaning / de-burring.

Loosing 15psi is an extremely slow leakage so would take ages to produce air bubbles in water.

i was losing about 5 psi a week!!

ended up was a slight crack on the rim

uhoh

I was loosing 10psi a week, when I got the tyre checked neither me or the other person could see air leaking took a 3rd person to notice tiny bubbles coming from the rim so I'd go for a second opinion

Maybe make up a strong soapy solution and spray that around the rim and the valve, this will allow bubbles to remain longer than just water - use one of these small plant sprayer pump things.

i will go for another check. Might be an excuse for some audi tt comp alloys though.

Would it just be a case of cleaning the wheels out? If not would putting the Gunky stuff inside the tyres help or fitting innertubes?