Thomas33

I can't believe I'm the only one who has experienced this, but Chevrolet seems to say so. My new Colorado came with Nitrogen (N2) in the tires, which call for 35 PSI pressure. As summer ends and fall comes, outside temperature falls. As temps fell a bit, my tire pressure (read first thing in the morning) fell from the original 35 PSI to 33 PSI - completely expected and normal. I drove to the dealer, a few miles away for the promised free "topping off" of any needed N2. In driving to the dealer, the tires warmed up and inner gas pressures increased, from 33 to 35 PSI.

The dealer told me that the tire pressures were as required, 35 PSI - hence no problem. I explained that the tire pressure increased from an initial cold reading of 33, to 35 PSI, of course, because of the act of driving it to his dealership. The cold tire pressure that morning was 33 PSI and so I needed +2 PSI - so would he please add that and then I'd be fine. I was told they couldn't help me because their N2 machine is set to adjust my vehicle to exactly the specified 35 PSI, and it is reading 35 PSI, so my tires were fine. I explained the physics of gases, that pressure increases or decreases as temperature increases or decreases, and etc. They explained their machine can't give more - it is set to the particular vehicle, and my vehicle calls for 35 PSI, and the machine is reading 35 PSI. So they couldn't add +2 PSI. No way to do it.

I called Chevrolet, and they verified that the dealer's machine is indeed programmed that way. They asked if I could leave the truck overnight at the dealer so the dealer could check and "diagnose" the tires. After venting some frustration (OK, much frustration), I told them I'd think about this requirement to drive again to and leave my new truck at the dealer overnight, to allow the dealer to verify that the tires actually do read 33 in the morning, and there are no other issues with the tires, in order to justify my request for +2 PSI. And no, this would not fix the problem in the future, when the tire pressures continue to follow the laws of physics while their tire machine will not. However, this would show that there is this problem that I am trying to bring to their attention. [And no, they cannot take my word and get me the +2 PSI. But if indeed there is this problem, then .... then what? Then they would have verified it. And no, their machines would still work the same way in the future.]

My question is, has anyone here come into this or a similar problem? What happened to fix the situation? I am tempted to simply add air from my air pump at home, to maintain proper tire pressures, as I have for many years - and thereby gradually lose the advantages of N2. But I am shocked that the engineers at GM could let this obvious defect in their N2 tire pressure maintenance pumps get through their system!

Please let me know...

Rednucleus

What is the nitrogen advantage?

Thomas33

A pretty good discussion on it is HERE - at Tire Rack.

kevinkpk

Nitrogen is inert gas, used on aircraft tires. I don't know if I believe any other advantage, or perhaps not as much water content in the nitrogen

Thomas33

That is the main advantage that appealed to me, when I learned that the Colorado came with N2 in the tires, and that the dealer would resupply for free, for life of ownership. I've seen the corrosive results of water in the tires of other cars I've owned in the past, around the inside of the valve stem. From Tire Rack:

tech2

try another dealership...either they are retarded or don't want to help you.
their machine is junk...every vehicles tires should be set to 2 psi over the placard.

I find it hard to believe anyone would make a machine you can't dial in the pressure you want. What if you have to do a loose tire repair (tire is there..car is not).

Really not that hard to fix this...if what they say about their machine is true...….total bs....set the machine for a vehicle that uses a higher pressure...disconnect the fill hoses and use drop the pressures by hand to what you need. If your concerned about corrosion in the valve stem, something I have never seen, use nickel plated valve stems.


I use nitrogen only because I have free use of the machine...I would never pay for it. Unless you race...a daily driver would never know the difference. Here's the real point....when you car goes in for an oil change or any tire work...each bay isn't plumbed for n2...you think a flat rate tech is going to leave his bay...drive to the n2 machine to adjust your tires. Never said by anyone...."my cars driving funny due to the atmospheric air you put in my tire"

Thomas33

Thanks for all your suggestions.... One comment on the dealership employees - I don't think it is a lack of intelligence or good will. There may be some of that there, but I haven't seen indications of it, but I do perceive fear - fear of the owner, fear for their jobs. It does not look like a happy place to work. And I have seen that fear, and nervous tension, in other dealerships of other car brands. Maybe it is this town, maybe it is widespread - and maybe if and as the economy improves, that will lessen. I hope so.

tech2

that unhappy look is employees losing money from a flat rate system. If you made 80% of your pay; how happy would you be.