[rls196906]

My engine is a rebuilt 305 transplanted into my 94.

The oil pressure gauge was not working when I bought the Blazer and I finally found the issue.
Normally as an engine revs, the PSI goes up. When i start the Blazer, the gauge reads 30 - 35 cold. The most it goes to HOT OR COLD is 40-45 psi.

I'm happy that I got it working, but is it working properly?? Are the OEM gauges known for any issues??
Or do I need to buy a new oil pressure sender and see if anything changes?

 

[bk2life]

but is it working properly??

You put a non factory engine in an S10. Zero person can tell you if your guage is reading properly.
What are your bearing specs? That determines oil PSI. Ask your engine builder for the spec sheet. It should have something like 0.0025-inch on main bearings and 0.0021-inch on the rod bearings.

Past that, you will need to add a second oil psi gauge to verify if your current gauge is reading correclty. There is no other way.
GM says 10 psi per 1000 rpms to be in spec for oil psi.
Generally, i dont install a oil psi guage, but just an 'idiot light'..
too many times have people been worried about oil psi when they dont need too

 

[rls196906]

I did not transplant the 305 and the builder is no longer around. I'll just live with the 30-40 psi reading. With gauges that are over 25 years old in Arizona and electronically signaled, like the circuit board behind the instrument panel, plastics lose their flexibilty and plastic needles dry out etc. So it was a shot in the dark that maybe there is an inherent issue with the OEM oil pressure gauge in this model.

 

[Rhotpursuit]

I did not transplant the 305 and the builder is no longer around. I'll just live with the 30-40 psi reading. With gauges that are over 25 years old in Arizona and electronically signaled, like the circuit board behind the instrument panel, plastics lose their flexibilty and plastic needles dry out etc. So it was a shot in the dark that maybe there is an inherent issue with the OEM oil pressure gauge in this model.

What kind of pressures were you expecting?

 

[rls196906]

I was just expecting the needle or the red bar to move, that's all..........

 

[bk2life]

you me and dupree.. (joke) Rhot above are all from az--
where you located?

 

[Rhotpursuit]

you me and dupree.. (joke) Rhot above are all from az--
where you located?

Looks like the big city...like you.

Going to take a little getting used to.

 

[PeteD]

Recco hook up manual oil gage and record cold and hot @ idle , 2500rpm.
Eliminate unknowns with fact to solve this dilemma. Verify electric gauge accuracy 1st.

 

[rls196906]

The oil pressure sender is a new unit but we al know that's no guarantee that it's working properly. That's why I sort of wondered if the Oil pressure gauge in the dash was an issue.

Good tips.......I'll see what happens....now where did I put that oil pressure gauge??????? hmmmm

 

[PeteD]

The oil pressure sender is a new unit but we al know that's no guarantee that it's working properly. That's why I sort of wondered if the Oil pressure gauge in the dash was an issue.

Good tips.......I'll see what happens....now where did I put that oil pressure. gauge??????? hmmmm

Gage function test by unplugging sender Should max w/key on.

 

[rls196906]

Thanks PeteD, I will try that today.....and report back

 

[rls196906]

Reporting back PeteD, I forgot that old trick of unplugging the sensor or sending unit like the fuel sender to see if the gauge pegs or just remains at zero.

Happy to report, the gauge pegged after disconnecting the oil pressure sensor. So it's not the gauge.

I'm glad I have smart friends...for some reason, maybe it's age, I've forgotten things like this simple test. I'm glad I have YOUNG smart friends to remind me.

I'll be happy just to see oil pressure when I'm driving and let the smiles and miles go by.😄😎🇺🇸

I'm calling this little project closed.

thanks to all who posted. 😉

 

[oldeerslayer]

Oops, post a link to a service manual on the wrong thread.
I moved it to the VSS thread.