Hi all, hopefully I can get some help here...I have a saturn and everytime I post in their forums I get ridiculed and ignored lol.

I've had this 93 gmc jimmy for a while now. It's a great running and driving SUV. I've done tons of motor and drivetrain work and have thousands in oreilys receipts saved up haha.

So now to the problem, all last summer and this winter I was getting great oil pressure.. Usually at or right round 40 psi. Getting on it hard would cause it to go above 40 psi. This past week I can't get it to hit 40 psi when warmed up.

I know the minimums are well below where it's at and that the stock gauge isn't accurate at all but it's just weird that it started this now. It's not knocking nor ticking so it's fine and never goes into red but it gets 2 bars above red which it never got this low before.


Things done this past month:
oil lines replaced( from radiator to filter and from filter to block)
Oil change (5w30 penzoil/quakerstate whichever is on sale and microgard filter)
Filter adapter gasket replaced with gm oem parts from dealer

Any ideas? The motor is the w code vortec cpi with about 160k on it. I'm not opposed to changing the oil pump but I hope it can be done without removed or lifting the motor.

 

by your back posts you have a digital dash - and as you stated the gauges in these vehicles can be inacurate even with the analog ones - with that being said you really don't know if your oil pressure was that high before or not - the change you are seeing could be in the sending unit or the gauge itself - if your conserned about the oil pump even tho it's a pain to do remove the sending unit add a t and renstall it along with a manual gauge to see what your pressures really are - and in most cases you have to at least lift the motor up to remove the oil pan to replace the pump and if 4wd its more involved

 

Where is the sending unit on these 4.3s? Back by the distributor but I'm not sure where exactly..nor what it looks like. Thanks for the advice I'll pick up a t and a gauge.

 

on the back of engine kinda under the distributor - almost at center - there might be a knock sensor on the riders side also but it will prob be about the center of the back side of the head on the block - i tried to get you a picture of my setup but no go as too much is in the way - wires and such - with the toy i built out of a 92 gmc jimmy {in my avatar} i installed stewart warner gauges but i also had to use the orignal oil sending unit for the old gauges too as it tells the ecm to kick on the fuel pump after oil pressure is up - most parts stores should have the t that you will need - it will have a short nipple and two open ports to screw the sending units into - or the old sending unit and a oil line if you use a manual gauge to test with