Left rear puncture. STOP....... 2008 C5 2.2 Excl.

[qprdude]

Warning came up tonight as I nipped to the shop. No puncture . I will give it a puff of air tomorrow in daylight to see if that cures it. After a warm day, it has turned very cold now and I'm wondering if expansion and contraction of air in the tyre has maybe caused the alarm to sound.
Anyone got any thoughts?

[qprdude]

Seems that the tyre sensor valves are prone to falling to bits, according to another forum. Horror stories of geezers getting stuck in with mole grips to get the caps off, and the valves coming apart in their hands.
Mine are hand tight with a touch of copperslip, so I'm not expecting any of that.

[qprdude]

Checked the car this morning. A short run came up with the same warning and alarm. Topped up about 8-9 psi (.5 bar) drove round the block and the warning has gone. Hopefully just a normal weepage over a few thousand miles, but at least I know it works. The sensors on the 2.2 Excl. 2008my are wheel specific, so rotation not as straightforward as a simple swap round.

[dnsey]

I though that TPMS only shouted if the pressure was about 25% below spec?

[qprdude]

Couldn't say, but the spec for 19" rims is 2.5 bar at the front and 2.3 at the rear, so I guess 8-9 psi is near enough 25% .

[Trainman]

Just reading this, and yes they are prone to corrosion, happens all the time with the C6, you can buy repair kits for them from Fleabay.

[qprdude]

Mine are in perfect nick, so I will keep them clean and protected.

[dnsey]

I hate to tell you, but the batteries will be reaching their end of life soon (5-7 years) so the sensors will need replacing if you want to keep the function.

[qprdude]

Ah well, I'll worry (or not) about that when they give up the ghost. They look so new that they might have been renewed before I got the car last year, or they could go on for a couple of years.

[Fuzzybrush]

I have 19" alloys and have a very slow leak from my front nearside after having a tyre replaced, I have yet to go back and have it looked at. At 2.05 bar I am told I have a puncture (thats 18%) and if I ignore it I am told I have a a flat when it reaches 1.9bar (24%) .

[spider]

The problem I used to get with these sensors when they first appeared (on Peugeot's at least, suspect they were at the same time, first car I recall was a 607) was the fact they used a metal cap which neatly corroded onto the valve assembly itself.

A slight design concern as far as I'm concerned although to be fair not something that would immediately show although if I remember correctly they were different metals used for the valve body and the cap so some metal to metal corrosion was likely anyway.

Quite a few customers used to come in to ask for plastic caps having had the metals ones rust on...

[qprdude]

Plastic caps standard on the 2008>

[spider]

Plastic caps standard on the 2008>

Ah they figured it out then. , not it was before that I'd gone in 07

[qprdude]

Probably cheaper as well.
I suspect they, like many others, used stainless steel valves and aluminium caps. (9or vice versa). Aluminium is always sacrificial to stainless steel and copper , and would corrode more quickly on our salt laden British roads. Regular cleaning and protecting would be the best way to prolong the valve/cap life. As the French don't seem to use road salt like we do in the UK, it's possible that the valves would last longer there.

[NAM]

National Tyres are now offering a service whereby they can replace or service the TPMS on all cars. There is a new EU directive in place