[sids911]

We've had four separate incidents where all four tires on our X3 went to near 0 PSI tire pressure overnight after a cold/chilly night. We almost never park the X3 in our garage but the neighborhood is really safe and we have motion sensors on the driveway - so it's not some kid playing a prank either.

At first I dismissed it off as a freak accident but it's happened 3 more times with almost similar conditions (hot day + ~30 F night + chilly morning= close to 0 PSI in all 4 tires), so me and the wife are a little suspicious with the tire/rim design. I mean I can understand one tire but all four tires experiencing the exact same failure pattern for a given environmental pattern does seem suspicious.

Anyway, the car is a 2013 X3 xDrive 2.8 and it's got the standard run-flats. After I limp over to the gas station and fill them up, the tires hold air perfectly fine for several months until the next such incident. Two of the run flats have been changed for different reasons but the problem has persisted across tire changes.

We're looking into a 2016 X3 but my wife (who <3's BMW) is really put off by these incidents. At this point, I'm wondering if anyone else has seen this too? I've reported this issue to Thomas a service manager at BMW of Encinitas but so far no insight into this.

Would appreciate any insight or incidents from others.

[pokerface]

Not really sure what can be done about this. Spring and Autumn temperatures tend to fluctuate a lot and that's how the pressure losses tend to appear. I'd say 90% of the population won't even bother checking tire pressures if without TPMS and would be shocked when they realize they've gone to 20 psi or below.

I wouldn't say this is specific to BMW X3. Perhaps you can mitigate with Nitrogen fill?

[MetaX]

Did you measure the actual pressure using tire pressure gauge or was it purely based on what the TPMS was reporting? I would suspect an issue with the TPMS rather than faulty tires and/or wheels--especially since it is affecting all 4. When winter rolls around I typically get a warning message that the tires are low which doesn't really surprise me given that air volumes drop in lower temps. For that reason I like to fill up my tires & reset the TPMS while they're cold so that they don't trip prematurely (you should reset the TPMS every time the alert is triggered). I'd start with reading off the actual tire pressures using a gauge to see how far the tire pressures are off from spec. If they are indeed close to 0 then sounds like you've got leaks on all 4 tires which is highly unusual.

[ejw2011]

If your rims are not cracked or bent, then my suspicion would be the tpms or the valves itself. It could be they are not torqued correctly or the valve gaskets are cracked and leaking. To test, spray some soap water around the tpms and valves and see if they bubble. If so, bring to dealer for repair.

[VinX3]

I have a feeling it was a prank. All 4 tires to 0PSI at the same time doesn't sound right to me. Time to put security cam around the house.

[Lotus99]

Yep, either a bad install with the bead on the tires on all 4 wheels or all 4 valve stems (which seems highly unlikely), or a prank.

The rule of thumb is for every 10° Fahrenheit change in air temperature, tire pressures will change about 2% (up with higher temperatures and down with lower). This means that light-duty, standard-pressure tires (typically inflated to 30-50 psi) used in applications on cars, vans and light trucks will change by about 1 psi.

[sids911]

Sorry for the silence guys, got busy with real life.

First off, this wasn't just the TPMS warning, I actually measured the tire pressure and it was near 0 on all 4 tires.

I've had 3 tires changed so far, so this has happened to 7 tires total as:
1st time: T1, T2, T3, T4 (all four to 0 psi)
2nd time: T2, T3, T4, T5 (all four to 0 psi)
3rd time: T3, T4, T5, T6 (all four to 0 psi)
4th time: T4, T5, T6, T7 (all four to 0 psi)
(I don't quite recall which tire is which, but you get the idea)

The rims have been the same set, which BMW claims are just fine. When I reported this last week, and BMW Encinitas checked it and said one tire (T7) has a "slow leak" and marked a spot on the tire where the leak was there; they wanted to change my tire for about $500. I had replaced T7 less than 40 days back, so took it back to Discount Tires.

At discount tires, the guys readily took in the tire after seeing the BMW report ("slow leak") but showed me the tub where the only place the leak was on the exact opposite side where BMW has market - at the valve stem. They replaced the valve stem and it's fine. Long story short, I'm not sure BMW did a comprehensive check on my reports of tire loss.

Back to the original topic, I *do* have motion sensors activated cameras on the front and nothing came up - there was no trigger whatsoever on the motion sensors (I test multiple times a week when I return late - it's hooked to our outdoor lighting too).

At this point, I don't know what the deal is. Honestly I'm returning this car back (end of lease) and picking up a new BMW 3-Gran Turismo shortly, so not my problem. The BMW 3-Gran Turismo is an awesome car BTW, drove last week!

LT;DR: I don't see any other readers chiming in on this, so might be an isolated issue with my car/rims. But car goes back to BMW, so not my problem (what goes around, comes around?!)