Tire pressure anomaly

[gcrain]

Warning came on two days ago and I checked and all the pressure were 28-29 psi according to both the car and the air compressor. Of course temps have gone from 90s to 50s so no big surprise. I pumped all 4 tires up to 35 psi yesterday and today they are all reading 28-29 psi again.

Any ideas?

[swexlin]

If you pumped them hot, it's possible. Just normal driving I can go from 29 cold to 33 warm. Heck, my dang warning went off in the Ram this morning....

[texasram]

Get a nitrogen fill

[Martin]

Get a nitrogen fill

Nitrogen fill might help a little - but it still has to obey the gas laws (PV=nRT). So, as temp (T) changes, so will pressure (P).

The other thing I wonder about nitrogen fills is if the installer actually evacuates all the normal air from the tire. Normal dry air is about 78% nitrogen to begin with, so if they only evacuate half the air in the tire, you're still not doing much better than what's in the inexpensive air.

Main thing to worry about is if there's DRY air in the tire to begin with. Unless the compressor has a water filter on it, you can easily shoot a lot of water into the tire, and as that evaporates and condenses, it can really mess with your pressure readings.

[swexlin]

PS -

Warning light shouldn't come on at 29 - that is "official" tire pressure cold. My tires have been as low as 26 on a cold morning, and no light.

Only time my light came on was when my left rear was down to 24, and I had a nail in the tire.

But these lights are funny. My Ram tires I normally have 36-38, and have been has high as 41 in very hot weather. In recent months, I have purposely not added air as I wanted to see how cold affected them. This morning, all tire pressures (at 29 degrees) were 31, except right rear was 30, and DING, warning light. It wants so see the pressure at 39. So I'll fill them.

Once the light goes on, it won't go off until you fill with the pressure the system wants. My Dart was this way as well. Hope this helps.

[texasram]

Nitrogen fill might help a little - but it still has to obey the gas laws (PV=nRT). So, as temp (T) changes, so will pressure (P).

The other thing I wonder about nitrogen fills is if the installer actually evacuates all the normal air from the tire. Normal dry air is about 78% nitrogen to begin with, so if they only evacuate half the air in the tire, you're still not doing much better than what's in the inexpensive air.

Main thing to worry about is if there's DRY air in the tire to begin with. Unless the compressor has a water filter on it, you can easily shoot a lot of water into the tire, and as that evaporates and condenses, it can really mess with your pressure readings.
Lets stay on the subject the OP presented please, Nitrogen filled tires typically lose NO pressure from permeation, So inflating your tires with high purity nitrogen, they will remain at their proper operating pressure much longer.

[texasram]

PS -

Warning light shouldn't come on at 29 - that is "official" tire pressure cold. My tires have been as low as 26 on a cold morning, and no light.

Only time my light came on was when my left rear was down to 24, and I had a nail in the tire.

But these lights are funny. My Ram tires I normally have 36-38, and have been has high as 41 in very hot weather. In recent months, I have purposely not added air as I wanted to see how cold affected them. This morning, all tire pressures (at 29 degrees) were 31, except right rear was 30, and DING, warning light. It wants so see the pressure at 39. So I'll fill them.

Once the light goes on, it won't go off until you fill with the pressure the system wants. My Dart was this way as well. Hope this helps.
I have a nail in my front drivers side to, havnt lost any pressure, is the nail still in yours or have you removed/plugged it?

[swexlin]

I have a nail in my front drivers side to, havnt lost any pressure, is the nail still in yours or have you removed/plugged it?

That was June of last year - it held some air, was a slow leak. Tire was able to be plugged, and I ran it another year no issues.

[Steve-Indy]

gcrain, did you drive your Viper after adding the air? If not, you may need to drive it before newly adjusted pressures register on Viper's display.

[texasram]

That was June of last year - it held some air, was a slow leak. Tire was able to be plugged, and I ran it another year no issues.

Do you know you date codes on your tires? we have same year vipers and was wondering if the nail issue/age is a cause for concern during high speed travel.

[swexlin]

Do you know you date codes on your tires? we have same year vipers and was wondering if the nail issue/age is a cause for concern during high speed travel.

I'm on a new set of Corsas I put on this year. I still have my old ones in the basement as spares. I can check the date codes, but they are getting old. Up to you if you want to replace, but it wouldn't hurt. Call Jon B, he has amazing pricing.

[texasram]

I'm on a new set of Corsas I put on this year. I still have my old ones in the basement as spares. I can check the date codes, but they are getting old. Up to you if you want to replace, but it wouldn't hurt. Call Jon B, he has amazing pricing.

Good ideah will do

[gcrain]

gcrain, did you drive your Viper after adding the air? If not, you may need to drive it before newly adjusted pressures register on Viper's display.

No I did not drive it, when I saw it was low again I turned it back off.

Going for a drive fixed it. After about a quarter mile the readings updated.

[Dave1968]

Lets stay on the subject the OP presented please, Nitrogen filled tires typically lose NO pressure from permeation, So inflating your tires with high purity nitrogen, they will remain at their proper operating pressure much longer.


https://youtu.be/bCnWvMleVD0

[Dave1968]

https://youtu.be/kmnZ4-EUbIk
A little more - just food for thought.

[Policy Limits]

Op- kuhmo or corsa?

[SuperBird4404BBL]

I had my tire pressure monitor module replaced under warranty a few months ago.

[Dr.Ron]

I had my tire pressure monitor module replaced under warranty a few months ago.

I had to do this as well. Tire pressure light came on while pressures were correct. The module was replaced under warranty and no more issues.

Ron