Hey all,

this may be a dumb question, but I've never owned another vehicle with an oil pressure gauge.

Normally in the morning when I first start the truck it is about 3/4 until it warms up and I start driving then it settles out at the half way point.

This morning after driving at 80mph on the freeway for a bit I went to park and noticed it was idling at around 1/4 to 3/8...

Is this normal? Maybe I've just never noticed it before. Truck isnt pouring oil out the bottom, lol. I plan to check my oil levels later on but I know it was perfect less than a week ago.

Does the gauge just go lower as the oil heats up/thins out?

 

I know that the gauges likely aren't super accurate or immediate... but generally speaking

 

It's normal to be higher on a cold engine, and as the oil gets hot, it will be lower.

As long as there is some oil pressure at idle, I wouldn't worry too much, as long as you see it increase as soon as you come off idle

 

I can always look forward to a Cleburn Red reply!

Much appreciated. I was pretty sure it was fine but I just wanted to make sure because I hadn't ever noticed it go that low before. As soon as you give it some throttle it goes right back to midway.

Take care bud

 

As long as your pressure goes up when your speed goes up it sounds pretty normal oil pressure in my experience with these trucks...

 

No problem, man! Sounds like it's OK. Always good to keep an eye on oil pressure, though!

 

15-20 psi at 550rpm in drive, fully hot in the summer after coming off the highway and using 5W30 oil is normal for a second gen Blazer. When you first start it up cold, oil pump will put out it's maximum against it's limit spring, which I believe is around 60 psi. As engine bearings wear and clearance increases, the hot oil pressure at idle will go down a little. Anything 10 psi and above at hot idle is just fine. High mile engines could use 10W30 in the summer, but that's the practical limit for using oil viscosity to correct oil pressure. More than that and things get problematic. Sounds like yours is just fine! Good job for paying attention.

 

If you're ever concerned about a potential oil issue this should really be step 1.

But yeah, in general 2/3 of the way is normal on cold start, 1/2 for normal driving, 1/3 or so at warm idle.

 

Generally speaking, my engine is a bit above half on the cold engine, then a little bit below, when hot.
But if You want to be more accurate, You have to look into the Vortec service manual (You can google it). There it is written what are the minimal values for the certain RPMs. Depending on Your mileage, it usually reflects the gradual wear of the engine, rather than the oil pump problems (which are non-gradual nature).

 

Sorry I dint update sooner but I got the oil sending unit out I got a socket for the sending unit but then I had to get a half inch rachet then the rachet handle was to long to move around so went to o'riles (insert sponsor ship message lol) an got a stuby handle rachet an poped it on the socket an I got it out. Turn out the insulation had melted onto one of the connectors. I hooked up the new one an it work better than before so I am happy. Thank you every one for your help an advice I do appreciate it. I'll post some video on here that I took.