Ok I don't know if you guys can help me or not but I am having some problems with my oil presser. I just changed the oil and filter I put full synthetic in it. Today I was watching my gauge and it is at about 35-38 psi idling and 40-45 at 1500 rpm but at idle it keeps going from 35 up to 40 then back down to 35-38 I took a video sorry its a cell phone video (Click on the pic to play the video)

 

Try a 180* t-stat, your oil is probably like water considering the temp of your truck.

 

Its running at 200 on the dot that is what it has run from the first day I got it and the motor only had 67000 on it

 

200* is fine.

What oil filter are you using, I suspect it's the filter.

 

I'm running a pruolator pure one the oversize one.

 

One more thing I did not say when I went to the bigger filter I have put 6 quarts in this time its about 1/2 quart to full.

 

Sounds perfectly normal. You should see the oil pressure gauge on the S-10 fluctulate when you rev it up. It moves like a tach.

 

Well you cant see it that good on the video but it will fluctulate at idle. I know it should go up when you rev it but is 35psi ok for idle?

 

Yeah, that is great. The only time you should worry is when it goes under 8 psi. The normal operating range is from 10 to 80 PSI. From the service manual.

 

35psi is plenty fine at idle, most engines idle closer to 20psi when warm in my experience.

The question is why it fluctuates, assuming your idle is steady.