So in all my years of car ownership I've never encountered a bad valve stem. I'm not sure if I should be concerned.

After service while driving back home, I noticed the ride was a bit bumpy. I checked the pressures and they were anywhere from 36-38. It was around 75F outside. When I got home I decided to bring the pressures down to 32. I did that on 3 of the tires. On the 4th tire, I found that it wasn't hissing when I tried to measure the pressure. The centerpiece of the valve was sort of depressed. Having never seen something like this before, I took it back to the dealership and the service advisor said that is normal. Is this something I should be concerned about?

Another thing I noticed is that even though my manual pressure gauge read 32 psi, the TPM on the dash was showing 35. Is this much discrepancy expected? Is 32 psi too low?

 

Tire pressure on my Tech is 33 on the plate. My TPMS reads about 2-3 PSI higher

 

This reminds me, I must go out today and air down a bit since it's gotten very warm here.

I find the TPMS on my vehicle to be pretty accurate. Either dead on or within 1 psi of my 2 digital pressure gages.

I don't ever recall seeing a valve stem depressed so far I couldn't take a reading while the tire is still holding air. There's either debris in there, an obstruction or damage. Usually, just poking a tool in there, momentarily will clear it out. I would be concerned with the tire suddenly losing all it's air. Get some new valve stems and a removal tool, if you don't have one. It might only need a cleaning.

Has the tire ever been inflated with flat fix sealer?

 

I don’t know what this is, but I’ve never had a flat or pressure issues with the current set of tires. I did have a flat when the car was new but damage was too close to the sidewall so I was forced to get a new tire.

 

Flat fix is a rubberized glue that you use a can to inflate your tire with, and it (supposedly) finds the hole and seals it.

A valve stem tool, with a couple of valve stems, is cheap and available at any auto parts store.

 

Tire pressure gauges are notorious for being all over the board on accuracy. No matter the price of the gauge mechanical or digital common s variation is +/- 1-5 psi.
It was so bad many manufacturers issued special tools to a least have something to calibrate against .
Dealers were over inflating by 3-5 psi to avoid the nuisance TPMS lights on cold morning in the fall.




If I had judge the accuracy I would compare it to the TPMS sensor value............which in the vast majority will be the most accurate.

 

I musta jinxed myself with my last post. Adjusting the pressure in my tires this morning, I got higher readings on the TPMS than my gage by about 2 psi. 33 on the gage, 35 on the TPMS. I couldn't find my other gage but I'm not gonna sweat it. It's not like I'm running at Talladega this weekend.

 

The valve mechanism may be stuck or jammed. You could try spritzing a little WD-40 or penetrant in there and gently manipulating the stem to see if you can get it to unstick. It's likely from when you or a tech was putting air in it and it went in crooked or whatever.

Also, the recommended tire pressure is for what the manufacturer feels is the best for gas mileage, handling, braking and ride quality. It's not a must, but a variance of ~4-6psi isn't going to hurt anything. Your mileage and handling may suffer a tad.

And yes, the TPMS reading was always a bit off compared to my tire meters. Which is more accurate? No idea.

 

OK, so the pressure looked stable today so at least I'm not concerned about a leak. It is still showing about 3 psi over what I set even in the morning. We have pretty bad roads around here, hence prefer a slightly lower pressure. Manufacturers know that roads are getting worse everywhere, yet they do little to smooth the ride, instead focusing on sporty looks and handling. When I was younger I preferred sport, but now with a bad back, I only care about comfort.

 

Go Toyota/Lexus or even Lincoln or Buick if you're more akin to comfort over sportiness. The RDX's ride, especially with A-Spec wheels, isn't awful, but it's not the softest either.

 

My hand was forced, and I am really enjoying the more peaceful ride of my Lincoln Corsair. The RDX handle great, as it was designed to. The Lincoln is close, but offers a much smoother ride.