have a question i have a 1997 doge ram pickup 5.9 4x4 whilr operating at normal speed the truck shows about 45lbs oil pressure then drops to around 20lbs goes back up to 45 it just started doing this after oil change any one else have this problem

 

Welcome to DF
I'll move your post to the 2nd Gen Ram section. I would try using a pressure gauge a see what the pressure is at when driving and at idle. Or maybe replace the oil pressure switch.

 

Does it begin to rattle? I would put a mechanical gauge on it asd see waht it is really doing. Sender may be bad or loose connection.

 

What RPM's is the truck at when you are running "normal speed"? And what is normal speed? How many miles on the truck?