Tyre Pressure

[Markus]

I have had an issue with the tyre pressure on the drivers side front, if I leave the car for over a week the pressure drops to roughly 1.70 bar and the light comes on. Toping up the pressure confirms it's not a sensor issue.

I took it to a Tyre specialist thinking I had a slow puncture but I didn't, it was fine.

So no faulty sensor and no slow puncture - why is my tyre leaking air?

 

[Eagle7]

I have had an issue with the tyre pressure on the drivers side front, if I leave the car for over a week the pressure drops to roughly 1.70 bar and the light comes on. Toping up the pressure confirms it's not a sensor issue.

I took it to a Tyre specialist thinking I had a slow puncture but I didn't, it was fine.

So no faulty sensor and no slow puncture - why is my tyre leaking air?

Leaky valve stem? The way I used to test for air leaks was to get a tub big enough to submerge the wheel at least above the edge of the rim, fill it with water, and put the wheel/tire in it standing up. Slowly rotate the tire and watch for air bubbles. That will let you see if there's an air leak in the tire, the tire bead against the rim, or the valve stem. If there are no visible leaks, then you might need to have the TPMS unit recalibrated (done with a magnet) or replaced.

 

[netsinah]

It sounds like taking the tire pressure reading of the "problem tire (tyre)" manually, shows a constant slow leak in one tire. So the OP confirms it's "not a sensor issue".

I've had a similar problem. It was caused by a poorly sealed rim edge...either due to the tire or the rim itself. It was only confirmed by the process of elimination, since taking the tire off didn't reveal any puncture or air leaks and the valve stem wasn't leaking. The leaks seemed to happen under load, while the vehicle was moving. Try taking the tire off, then off the rim. Have them check for smoothness and any visible imperfections on the rim and tire inner edge. With the tire off the rim, clean and reseal the rim/tire edge then reinstall the tire. See if that works.

If not and it's still driving you crazy, consider swapping the problem tire with another good one on your vehicle, so swap tires by putting them on different rims, all from your vehicle. See if the problem remains with the same tire (in its new location...so you know it's the tire)...or the same rim (in the old location, so you know it's the rim). Hopefully in that fashion, you'll know if you need to replace the tire or rim. Wish I had an easier suggestion. Good luck!

 

[Matt]

Try using the pump to read the tire pressure and see if it is the same as what is shown in the car。

 

[Matt]

If your tire pressure setting is 2.0 in the front and 2.2 in the rear, it is normal for the front tire to drop to 1.7 after more than a week, and the tire pressure will indeed decrease if you leave it for a long time, especially after the temperature change.

 

[Markus]

Thanks everyone. It sounds like a poorly sealed rim edge is the most likely. I will head back to the garage and ask them to check the seal. A bit frustrating topping up the pressure every time I use the car. Thanks all.....

 

[Kimmax]

pressure will indeed decrease if you leave it for a long time, especially after the temperature change

I overpressured mine and parked the car for 4-5 months and they barely dropped pressure. 0.3 loss after a few days on one tyre only is not normal.

 

[Xroyalnavy]

I overpressured mine and parked the car for 4-5 months and they barely dropped pressure. 0.3 loss after a few days on one tyre only is not normal.

Anyone using a nitrogen fill?

 

[MaybeNeedEmira]

Anyone using a nitrogen fill?

As a guess, 78% of people don't know what's in their tires/tyres.

 

[Porter]

Anyone using a nitrogen fill?

It's useful if you live in a humid or damp climate, but in most temperate zones it's not a huge difference compared to reasonably dry compressed air. The trouble sometimes is the "reasonably dry" part... many home compressors don't have a water separator, so in those cases a nitrogen fill is better because it's a very dry gas. But ultimately it's about the water content, not about nitrogen being objectively better as a fill medium compared to air.

 

[Rudolph]

* * * * *
I have a 2021 Evora GT 410 Sport on Michelin Pilot Sport Cup 2 with 2.500 mls.
All 4 tyres keep their pressure level excactly over a period of over 3-6 months....
This was different with my 1990 Esprit Turbo SE (owned 1993-2021) .........only 2-3 weeks

 

[lynchy73]

Thanks everyone. It sounds like a poorly sealed rim edge is the most likely. I will head back to the garage and ask them to check the seal. A bit frustrating topping up the pressure every time I use the car. Thanks all.....

If nobody can find a leak in the tyre or valve, it might be worth raising it with Lotus. If the tyre isn’t sealing on the rim, that kind of sounds like a wheel issue, and surely that could be considered a warranty issue?

The tyres on my Emira haven’t changed even slightly in 4 months. Only time I’ve lost tyre pressure on other cars I’ve owned (within reasonable time frame), I’ve always found a screw or suchlike in the tyre.