Tyre pressure warning - run flat tyres

Tyre pressure warning - run flat tyres

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purple haze

Original Poster:

259 posts

226 months

Wednesday 2nd August 2023
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My wife's 2017 Cooper S has 18 inch rims and apart from the fact that the ride seems harsh and noisy she also seems to get a lot of tyre pressure warnings even though the pressure is only down a couple of pounds. It's getting to be a pain to go though the reset process. Any one else had similar?

un1eash

605 posts

142 months

Wednesday 2nd August 2023
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Once set you should only see warnings if they drop 0.3 bar or above. If your getting more alerts it's likely the batteries are going.

s-x-i

169 posts

51 months

Wednesday 2nd August 2023
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Off Topic - I would recommend ditching the run-flat. We did this to our MINI and it totally changed the car.

On Topic - It could be a faulty (leaking) valve? Do all tyres loose pressure or is it just certain ones?


Olivera

7,270 posts

241 months

Wednesday 2nd August 2023
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The runflats are dogst and if you are setting pressures to MINI recommended values then they'll be at some ludicrous 45-48 psi value, resulting in a trolley going down a flight of stairs ride.

mikeswagon

712 posts

143 months

Thursday 3rd August 2023
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When you say the pressure is only down a couple of pounds, is this compared to the recommended pressure?

As has already been stated, once reset they'll quite happily run at this without giving errors, they only detect a large drop in pressure from the reset levels.

From the age of the car, I'd say almost certainly the batteries have about had it.

BOR

4,726 posts

257 months

Thursday 3rd August 2023
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Seems early for the batteries to have failed. Mine were still OK after 8 years, but I know it depends not just on time, but how often the sensors send a signal.

I don't think I ever saw a false alarm, and would have thought battery failure would just not show a reading?

I would have to be completely certain that it is not simply the tyre pressure changing with summer/winter air temps, or the expected loss of air through the tyres over time, before replacing the sensors.

The sensors aren't cheap, + cost of removing/refitting the tyre. (Partly how I justified complete new wheels and tyres biggrin )

purple haze

Original Poster:

259 posts

226 months

Thursday 3rd August 2023
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Thanks for all the comments. I'll respond to comments & questions and then ask some of my own! My wife has had the Min for a year now and I've had to reset the tyre pressures at least every couple of months. The tyres ( Pirelli 205/40 on 18inch White Cone Spoke alloys) are routinely set to 42 front 39 rear as per Mini recommendations . Typically the tyre warning comes on every 6 weeks or so & when I check the tyres they are usually down 3 to 4 pounds a tyre. It's not just one tyre - they are all losing pressure to varying degrees. We don't go on a long trip without a gauge and pump in the car now.

As for the ride well it has surprised me just how harsh and noisy it is on most road surfaces. it is, no doubt, not helped by the high recommended tyre pressures. My Porsche Boxster has 19 inch rims with 235/35 fronts and 265/35 rears running 32 front & 36 rear pressures and its ride is incomparably better than the Mini - and a whole lot quiter. I'm running Michelin Pilot Sport 4S on the Boxster and its a fantastic tyre.

If we were to consider changing tyres (and smaller rims? - although my wife does like her white cone rims) any recommendations would be carefully considered.

GT4P

5,234 posts

187 months

Thursday 3rd August 2023
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Might be worth checking that the valve inside the valves are tight you can get a little plastic key to do this.
I replaced the tyres on our F56 JCW 18 wheels(205/40x18) with Michelin PS4 (215/40x18) The slightly larger tyres were cheaper than 205 width and run no problems

mikeswagon

712 posts

143 months

Friday 4th August 2023
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Ok so we've established that the tyres are actually going down, so it's not a TMPS fault really, is it?

I'd go old school, make up some soapy water and put around the base of the valves, and inside the valve cap, check for any obvious bubbles. Could be the centres weren't tightened properly the last time it had tyres.

Good luck, these things are a pain.

Pip1968

1,348 posts

206 months

Tuesday 7th November 2023
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purple haze said:
My wife's 2017 Cooper S has 18 inch rims and apart from the fact that the ride seems harsh and noisy she also seems to get a lot of tyre pressure warnings even though the pressure is only down a couple of pounds. It's getting to be a pain to go though the reset process. Any one else had similar?
What was the outcome of this?

I am a fan of the runflats as it is a small price to pay.... a crashy ride... knowing your wife can contiune on her merry way despite having a puncture. She has history. One year having supposedly reset the TPMS I returned from abroad finding she had been driving for a few weeks with 20 PSI in one tyre (runflat) and had turned the TPMS off (r53).

We now have the F56 and I am not sure you can turn TPMS off but as for robbing people of the cost of a new valve every few years I have to say that I am furious. As if cars are not expensive enough. Anyway we have had the car for just over a year now and had to reset the TPMS twice so far (three times if you include the puncture she got last week.

Pip