I'm sure this has been mentioned before, so y'all can take this as a reminder. One of the first things I bought Zaftig were good metal MINI logo valve stem caps. Fast forward 2.5 years to this evil winter and multiple TPM warnings and resets. I decided to check air all around and top off the tires, but none of the caps would come off. Doused them all in penetrating oil, let them sit awhile, and tried again. The first one resisted, then twisted - only trouble was that it twisted the stem and snapped it. I have an appointment on Friday: tire dismount and remount ($40) and valve stem replacement ($40). I'm letting MINI do the first one as I have a trip on Saturday. The stems are $15 to $20 on line and I'll shop local tire places to see who is cheapest for the rest of them. Live and learn.

Side note: I also have cheap sets of plastic logo caps on my T-Bird and my Ranger. No metal-to-metal interaction and they twist right off even after several years.

 

Yeah I've seen a few threads on here where the fancy metal caps fused to the stems. Definitely sucks.

Your story kind of implies that you haven't removed the caps in 2.5 years, but surely that can't be the case?

 

Zaftig never gave me a reason to twist his caps till this winter. I guess the factory air is good up to 10,000 miles?

 

Don't rely on your TPMS sensors to tell you when to add air to your tires. Get yourself an accurate tire pressure gauge (they're not expensive) and make it a habit to check your tires' pressure levels once a month.

 

Just a dab of anti-seize on the stem threads will prevent that from happening again.

 

I hear vaseline works too.

 

I'm guessing I'm somewhere between lazy and stupid. I have a gauge and use it frequently - - - on the Bird and the Ranger. Time to retrain this old dog. And I'm sure Zaftig would appreciate the attention and a little anti-sieze on his stems.

 

Brass valve caps won't stick to aluminum or steel ... if you can find them.

 

I have the "S" caps. They look like metal,but they are actually plastic. The metal ones must be corroding to the stem.

 

Depending on grades of the metal and the environment (harsh in this case) they sure can. Aluminum has an Anodic index of 0.95V, Steel is 0.85V, and Brass is 0.40V. For a harsh environment like winters up north and salted roads a difference of 0.15V max would not cause a galvanic reaction/corrosion. I would either get new caps more frequently, remove and check air monthly as you should, or just dab a little anti-seize in there when you do check them once or twice a year.

 

Good info. I guess the metal in the valve stem and cap have to be compatible.

 

Thank you professor.

 

Well, that was fun. Two hours and $70 later, I'm back on the road. With a stern admonition that the other 3 need be done, as well. They put in a new silver stem and when I questioned it, they said it was correct for my VIN. Also said the others look black because of road grime and they are really silver as well. At this point, whatever. But why the need for BS? Moral dilemma: I have 4 months until I turn it in. Do I change the other 3 or let the next guy worry about it?

 

Your answer may be different but my answer is always, What if I were the next guy?

 

So...You only put air in one tire?

 

If you were the next guy? Well . . .

Currently only have access to one tire. I'll order the stems and find someone on this side of the river to take care of them. Unless I know the car is going to Texas when the lease is up.

 

Were they MINI OEM accessory caps (like these), or aftermarket? I thought MINI switched all their accessory caps to plastic back in 2007 when they started using TPMS stems.

 

I thought air pressure was checked as part of oil service. Sounds like Zaftig did not get the full treatment he deserves.

 

Well, the saga continues. I loaded up Zaftig on Saturday and headed out for a 400 mile round-trip. At about 60 miles I get a TPM Inactive warning. Off and on throughout the journey, it would resolve and reappear. Every time we'd stop, I'd do the reset, but it's still off and on. I also have a strange grinding noise from the area of the wheel they remounted. Just once I'd like to have my car come back with a full resolution of the problem and not more issues than it went in with. I'm giving up on Passport until I turn Zaftig in and I'll be making an appointment with Annapolis to have the other 3 done and to look at what Passport did.

 

Saga Continues, Part II I took the day off to chauffeur my husband to an appointment with an orthopedic specialist (broke his leg last Tuesday). No surgery, but off his feet for 5 weeks and a spiffy no walking cast. Headed to his office in VA to pick up papers. The whole time TPM is off and on. But, as a bonus, as we get into VA, the check engine light comes on and I loose power. Picked up paperwork, as it is on the way to Passport, restart the car and we now have TPM, Engine, and remote battery depleted. Dropped it off at Passport and told them to keep it as long as they needed to, but don't call me unless it was right. These last four months may be the longest term of the lease. Let them know that I already had a replacement ordered and it was not a MINI. (It is a 2014 Mazda 3). We're just going to be calm and patient.