So I got my truck saturday. Bone stock Sierra Denali, but it does have 78k miles on it. I noticed on the highway that the pressure was below 40psi and it doesn't ever really get above 40psi - EVER. At idle and warm, its around 19-20psi and on start up its seems slow to pressurize. Anyone else notice this same thing? All of my other LSx motors have had much better pressure than this. What are your thoughts?

 

Once the oil warms up, I don't see any more than 40 psi on mine. The smallblock in my S10 is the same way.

 

bout right. my moms yukon denali does the same thing.

 

I guess I just thought it would have more pressure than that.

 

My 09's LY6 is similar. It hangs just below 40 at highway cruise and might hit 50 psi with it to the boards turning 5500 rpm. Idle is around 20-25 psi. Engine has 56000 miles on it. For comparison sake my LQ4 in my 05 idles at just below 40 psi, runs around 55 on the highway and hits 70 when I floor it. Both have about the same mileage and same oil used. It's just the nature of the beast.

 

Hmm seems alittle low, My 2011 6.2 Has around 50-60psi cold starting and hardly ever falls below 40 once its warm. Food for thought.

 

I noticed when I went to lunch, my cold PSI was around 50psi, well not even really cold, but 180* it looked like.

 

my "gauge" says 40 cruising but my dash hawk shows 47-48 cruising

 

This is because of the relief valve that is in the pan near the oil filter. Around 40 is pretty normal. Sometimes idle can be in the 20-30 range.

 

but what about below 20 idling warmed up?