[nazali]

so, I check my tire PSI's monthly.

Last month, by my digital hand gauge, it showed
f=32 , r=36 & 37
I pumped them up to the f=35 r=41

My digital hand gauge also concurs with the BMW tire gauge

Today when I check, it showed
f=32 r=39/38
I didn't check it with the gauge

so some questions, is 3psi drop on both front tires OK ? does it indicate any problems, also the rear show a 2 & 3 psi drop respectivly

should I have any concerns

I think there is a 20% rule, so for me
35 no less than (7) or 28
41 no less than (8) or 33

I like to adjust if 2psi difference, 3 doesnt do my OCD any good

LOL

[dradernh]

Note that there's a rule of thumb that says tire pressures will vary by 1 psi for every 10° in ambient temperature variation.

[nazali]

I didn't know that rule, but yes, I'm aware tire PSI, can vary with temp, I usually try an do it 1st thing in AM, on stone cold tires,

thank you though

Originally Posted by dradernh

Note that there's a rule of thumb that says tire pressures will vary by 1 psi for every 10° in ambient temperature variation.

[Ajowhan]

Since all 4 corners drop about similar psi, most likely its the ambient temperature things affecting your pressure.

But if you are measuring it 1st thing in Am and assuming no season change and lose 3psi in a month, that could be indicative of a slow leak. I would change out the valve stem and see if that helps.

[nazali]

the valve stems are part of the TPMS sensor ? So I would need to replace the TPMS ?
I might get my tire guy to removed and reseal them

as all 4 are loosing, maybe they are just badly sealed ?

[Ajowhan]

Originally Posted by nazali

the valve stems are part of the TPMS sensor ? So I would need to replace the TPMS ?
I might get my tire guy to removed and reseal them

as all 4 are loosing, maybe they are just badly sealed ?

Can't tell you much more without risking giving you false information tbh. I did have my valve stems replaced without needing to replace the TPMS when I got a new wheels in the past. (Not on the 2 series).

Valve stem are relatively inexpensive. Hell I think one time when I took a car into America's tire and ask for their help with leak, they replaced my valve stem for free.

[aerobod]

The valve stem and seal for the TPM sensors are available separately: https://www.schmiedmann.com/en/produ...6-10-6-876-673 part # 36-10-6-876-673. I would try tightening the securing collar first, though, but not too tight to avoid damage, the torque should be about 3.5Nm.

[nazali]

ok thanks I think I get it,
if I start or keep loosing too much,
I'll get my tire guy to have a quick looksie