Low oil presure

[Sparksmcgarks]

I have an 86 cucv blazer with a 6.2 the oil pressure was dropping to around 10 psi at idle I just replaced the oil pump and pickup tube but it’s still low around 18-15 psi. Is this normal or am I lookin in the wrong spot. Any help would be appreciated as I’m only a you tube mechanic

 

[Bent77]

What oil are you using?

 

[Sparksmcgarks]

Rotella 15-40

 

[Bent77]

That’s what it should be for spec and quality, good there


No trash in the oil or filter?

 

[Sparksmcgarks]

None that I saw no

 

[Truckman4life]

Are you going off the factory gauge or have you installed a gauge to verify the pressure?

 

[Truckman4life]

Checked the GM manual and I think you are fine at idle.

 

[centexk5]

My last 350 did 1-2psi at hot idle and maybe 30psi at 3k rpm’s. Ran fine for years.

 

[Bent77]

My last 350 did 1-2psi at hot idle and maybe 30psi at 3k rpm’s. Ran fine for years.

I’m betting that gauge was off

The original engine on my 77 carried 15 psi at idle with 2 cam bearings washed out. 45 psi at rpm

 

[Bent77]

Checked the GM manual and I think you are fine at idle.
View attachment 480956

Thanks for posting that. I was hesitant to speak out of turn as to what the diesels needed due to the compression

 

[Truckman4life]

Thanks for posting that. I was hesitant to speak out of turn as to what the diesels needed due to the compression

In the specs section it says 50psi but when you go to the lubrication section 10psi is all good. My oil pressure gauge on my 6.2L is always the same. I just go with with it.

 

[centexk5]

I’m betting that gauge was off

The original engine on my 77 carried 15 psi at idle with 2 cam bearings washed out. 45 psi at rpm

It was a mechanical gauge hooked straight to the port by the distributor.

 

[Bent77]

It was a mechanical gauge hooked straight to the port by the distributor.

As is mine. Not sure how accurate those factory gauges are

 

[centexk5]

That’s why I run aftermarket.

Believe me it made me nervous. But it ran for years and crawled and no issues. The transmission on the other hand. Well let’s just hope @fourwheelerjeff knows how to rebuild a th350. That thing created more mud than a hurricane in Louisiana no matter how many flushes it had.

 

[CT-BLAZER]

Trust a mechanical Auto Meter oil gauge....

Diesels run hot.....mine have 30 ,or SAE 40W year round...

If I'm going to be in the Canadian border I run Valvoline Semi Synthetic 30W oil.
car starts fine with out the block heater

 

[imiceman44]

Thanks for posting that. I was hesitant to speak out of turn as to what the diesels needed due to the compression

As a rule of thumb for all diesel engines 10psi per 1000 rpm is safe

 

[Bent77]

As a rule of thumb for all diesel engines 10psi per 1000 rpm is safe

Go by the same for gas engines. Just wasn’t sure what the spec was at idle. Didn’t want to give out bad info