well I encountered another issue someone may have some insight on. when I go and start my 1993 1500 5.7, the oil pressure takes a minuite to pick up and it knocks quite loud for a second until the oil picks up and then when I drive it for 30 min plus the oil pressure gauge only goes to the first indicator on the left almost like it's going in the to the red area. But when I first start it and oil kicks up it's at it's normal operating position. Can anyone put some insight in what to do??? Thank you.

 

It sounds to me like your oil is possibly breaking down. I am in no way an expert just a backyard mechanic kind of guy. I run Mobil 1 full synthetic 5w-30 and Lucas Oil Additive. The lucas additive is extremely thick, almost like caramel. It helps keep oil on parts for start up. Maybe someone else will have a better idea. I have an 01 5.3 and my oil pressure stays around 40 or just over.

 

I don't think it's the oil breaking down because I just did a oil change on it about a week ago and am running the same full synthetic oil you are - the lucas treatment. I'm just hopeing it's not my engine giving out because even when that oil pressure is up the engine still doesn't sound right....but's it's not knocking like it does when I first start it up...good idea though.

 

Those guages go screwy sometimes. My 91', it the guage would go back and forth super fast at times between 60 and 80 psi and then would settle in the middle. How many miles on yours? If the engine is sluggish it might need and overhaul.

 

The knock on start up could be your lifters. On an older vehicle the oil will drain out of them overnight causing the sound you hear. It goes away after the lifter a filled up again. There is no temporary fix, your gonna need a new set, it will only get worse. Get an analog pressure gauge and check the oil pressure, the pump may be failing. If that is the case you will need to replace it soon to avoid damaging the motor to the point it needs a rebuild, assuming it is not there already. If you have other means of transportation until you can check this out that would be best. Check pricing on the sending unit. If it's not much change it, but, I wouldn't be comfortable until I new for a fact that my pressure was good.

 

awesome thank you cracker for your help. I will be getting that checked out...the truck itself seems to have a ton of power still but I believe your right with the lifter situation it's sounds more like it but still I will get the sending unit checked out. Thanks!