Oil Pressure problems?

[Faustk5]

Ok I was driving home yesterday and noticed my oil pressure gauge was almost at zero. It was driving fine, strong actually going 75 up a steep grade. Got home checked oil levels, was fine, oil was changed a few months ago and still
Looks clean. Crawled underneath and there was a little oil leak from somewhere. Tightened up the drain plug seemed excessively loose. Started it today and the gauge went up to halfway, came back out after 10 mins of idling and it was hovering just above 0 again. Any thoughts on what it could be?

 

[919jackass]

how many miles on motor, which one, what kind of oil are you running and what year is truck check your gauge first then look down inside you valve cover to make sure oil is moving though the push rods and into the rockers

 

[sweetk30]

what brand filter ?

FRAM = DEATH

 

[Faustk5]

It's the 5.7 tbi, 1989
Supposedly only 116,000 miles but I've only had for a month so who knows
5w30 and a acdelco filter

 

[ryoken]

drop a mechanical gauge on it to verify...

 

[sweetk30]

i had a factory sender start leaking a tiny bit so i changed it . afterthat i gaind 5psi or so overthe range from before .

the sender was going bad for a long time.

like said get a QUALITY mech gauge to test it with before going much farther.

and glad its not a fram on there.

 

[919jackass]

faustk5 did you have a chance to look at it yet ???

you can also check that gauge by adding power then ground to the wire going to the sender and having someone watch the gauge it should go all the way up over 60 then all the way down past 0. i suspect the sending unit by the oil filter

 

[Faustk5]

No I haven't had a chance yet. Hoping to do it this weekend. Sucks not driving it and really hope it's the sender. Thanks for all your input and I'll let you know the outcome. All the downtime has given me and opportunity to gut the inside and prep for new carpet.

 

[4xcrazy]

First thing I would do is change out the sender. Relatively cheap. I had one that always read high, I didn't think anything of it, thought I had great oil pressure, I changed it out one day for some reason with a new one and the pressure reading went back down to a normal range for these engines.

I would probably also run a slightly thicker oil as well. I always ran 20/50, but my engine had over 200k miles and since I live in Phoenix, nice extreme heat doesn't do any justice to motor oil.

Just had one on the Avalanche last year, would always read up near 80 psi, but when on the throttle real hard, it would drop to 0 and set off the dash warning bell. Turned out, again, to be a bad sender unit. installed a new one and been fine ever since.

 

[Faustk5]

Well finally had a chance and a few bucks to work on the blazer. I put on a manual gauge and it was reading 30-40psi which was a huge relief. So I put a new sending unit in and.... Same thing. So it was just the gauge. Put a new gauge in and all is now good. Now to start the same process with the fuel gauge!!
Thanks for all the help

 

[sweetk30]

check the frame ground to sending unit.