F30 3 Series 2013 TPMS No warning light !!!

[Please help]

Hi all, just noticed a strange sound coming from the rear near side tyre. I checked the pressure when I got home and it was next to nothing !!!!.

So I put enough air in and went for a spin and the noise has gone. So I suspect I have a puncture somewhere. I was just wondering why the TPMS didn't pick this up ?.

Has anyone encountered this or know what the reason could be ?.

I do regularly check the pressure and reset the TPMS. All the other tyres were fine as I checked them too at the same time.

Thanks

[Fox-]

Please help said:

Hi all, just noticed a strange sound coming from the rear near side tyre. I checked the pressure when I got home and it was next to nothing !!!!.

So I put enough air in and went for a spin and the noise has gone. So I suspect I have a puncture somewhere. I was just wondering why the TPMS didn't pick this up ?.

Has anyone encountered this or know what the reason could be ?.

I do regularly check the pressure and reset the TPMS. All the other tyres were fine as I checked them too at the same time.

Thanks

Your F30 probably doesn't have TPMS - it was standard only from 2014 onwards. Older models had Flat Tyre Monitor which uses the ABS sensors and doesn't respond quite in same the way.

[Please help]

Thanks for your reply.

So does the TPMS work in a different way ?. As I can go into the settings via the idrive and view the system. It also let's me check the monitoring system. I'm not sure what it's meant to show or what purpose it then serves ?.

[anonymous-user]

Both systems are technically a TPMS, though the sensor valve system on later cars is the only one that actually monitors pressure directly. It’s known as a direct system, the ABS type is an indirect system.

I believe both are still legal (I stand to be corrected) but direct systems are becoming more the norm.

ABS based systems are known to be slow to register, you need a big difference in pressure for quite a while across the axle for the system to notice.

Again as far as I know most, if not all, BMWs have had the indirect system for many years; both were offered for a while, I’m not sure what they offer now.

[Fox-]

All post 2014 BMW's now have the direct system IIRC.

[Please help]

Many thanks. I am surprised I didn't get a warning of any kind show up as there was hardly any air in the tyre, although it didn't look flat as a conventional tyre would (these are the first run flats that I have had so not sure if that's normal or not).

Although as you say I may have not been driving long enough for it to register as it was only a short journey.

I have Just read that the valve stem is a clue, plastic or metal. So I will have a look in the morning to see what I've got. Metal is meant to signify TPMS ?

[anonymous-user]

Metal signifies a sensor valve. ABS systems generally have snap in rubber valves, though it’s not inconceivable to find one with a metal clamp in valve.

It’s normal for these RFTs not to look flat, that’s how they work. The correct terminology is Self Supporting RFT. There are, or have been, other run flat systems like the Michelin PAX or Bridgestone Runflat system which had completely different principles.

The former was a unique rim and tyre design; the latter used an insert in a standard rim and tyre.

[Please help]

Many thanks for your replies.

Much appreciated.

[aeg]

As above, E9x and early F3x had the ABS type, now all sensors.

Rather embarrassingly I drove for up to two weeks (around 800 miles a week) with probably no air in a rear tyre - I only know this because it was two weeks since I had manually checked the pressure, then had some new rear tyres fitted, only for the fitter to find NO AIR in one of the tyres - it hadn't felt bad - worn run flats didn't feel great anyway, and there had been no warning from the TPMS at all! The sensor type is much more reliable, but this just shows you can't rely on the ABS type (with rubber valves not metal).

[Please help]

Blimey. Just shows how unreliable the warning system is. I would have thought the TPMS would be more reliable than the one that I appear to have on my car.

[anonymous-user]

It also seems to show how tough an RFT is, though I very much doubt one would run more than a couple of hundred miles fully deflated. Especially at normal speeds.

A colleague of mine had a mini that suffered a rear puncture just as he got onto a cross channel ferry a few years ago.

He disembarked and drove steadily home to Stafford. He got there but the tyre was barely hanging together at that stage.

[Please help]

They do seem tough. If it wasn't for the noise that I heard from that side of the car I wouldn't have known.

I still have the same set from when I bought the car from new although I don't do a lot of miles. They came with the Dunlop SP Sport and they have been fine.