The topic of filters is for another thread. You want to praise them, please start a new thread on the topic.

 

Guess you just made my point??

 

The idle is not THAT bad. It fluctuates just a little bit, my main concern is the oil pressure gauge jumping around. What could go wrong, because my blazer ran excellent last week.

 

If the oil pressure were to dip too low, you could have oil starvation issues. Now seeing as how it only happens at idle the damage would be minimal, but cumulative. Check your wiring to the oil pressure switch as well as the switch itself as blazingsadle has suggested and see how that goes. If everything checks out fine there, it's possible that something is amiss inside the engine.

How many miles are on the truck?

 

My concern is simple enough. If your engine happens to have something simple wrong like a small leak in the intake or a bad vacuum hose that makes it idle a little rough. Then all else is a conversation we dont need to have. The oil pressure and even some other gauges might fluctuate.

If on the other hand, you are really worried about oil pressure. Attach a MECHANICAL oil pressure gauge and check it for real. It'll be worth it to know, once and for all. The problem might just as easily be that gauge itself. I'v personally replaced 4 or 5 of them in 85 to 95 vehicles. Easy enough to pull the dash and change it. But check it against a mechanical gauge. Yes you may have to get in some tight spaces, but it can be done and can be remove when you know better.

I have read somewhere, (dont hold me to this) that the oil pressure sending SWITCH not gauge unit, will only shut the motor (fuel) off at 7-8 pound of (oil) pressure. My own that I install are 15 pound ones, and I had always assumed that the factory ones were also. I no longer believe that. I believe they are not really installed to protect the engine, but are there in event of a traffic accident and engine shut off with key still on. With the key still on the pump would continue to run and with the ignition circuit still hot an explosion could result. It is a safety switch and not to keep the engine in one piece.