Oil pressure question

[Brl2005]

On colder days, when I first start my ram 2500 5.7, I get no oil pressure reading. However, if I turn it off and restart it, the oil pressure gauge reads properly.
If it’s warm outside or has been kept on a garage, it read the pressure at the first start.
Any ideas on what this could be?
Thanks, Brian

 

[MADDOG]

Thicker oil viscosity. The oil has to warm up a bit more to flow when cold. There may also be some cold, thick, oil clinging to the sensor.

 

[SYKRAMMAN]

^what he said^

 

[Brl2005]

Thanks for the replies. I’ve been using the same oil for over 10 years. This is a recent problem. Could it be a sensor