99 Tahoe oil pressure

[slingblade]

Recently I had Snappy Lube change the oil in my '99. Afterwards I checked it and they had overfilled it with 6 qts. My oil pressure gauge indicated very low oil pressure around 3-5 lbs. when idling and 10 at highway speeds. I drained the oil and replaced it with the correct amount. The gauge still indicated the same. Thinking they blew out my pressure switch I replaced it today. The gauge still reads the same usually at zero when idling and 5-10 driving. There has been no noises from the engine or smoke, and the oil level is correct. It has 160,000 and , maintained regularly.
I know that I need to obtain a reading from a mechanical gauge but I do not have one and probably replace the oil pump.
Now riddle me this......has anyone replaced an oil pump any what kind of pain in the ass is it going to be? I need to get a few more years out of her.
Any and all help is appreciated in advance

 

[994door]

try a delco oil filter, its cheap and worth a shot.

 

[AtomicHoe094]

yea usually if i run a fram filter, my truck will want to kill me. The oil pressures always wacked out with that fram, but once i change it to ac or mobil1, its fine. idk, but yours seems pretty intense. sorry

 

[slingblade]

Talked to a mechanic that told me to try and remove the oil filter and check the oil by-pass valve in the block where the filter fits. He said that sometime the spring loaded valve can get jammed and cause the by-pass to stay open and create low oil pressure.
Drained the oil, could not locate the valve which had shown me on a old block he had laying around so put a new purolator oil filter on and heavier oil. Still same problem, oh and did I mention I changed the pressure switch. Mechanic says unless it starts making lifter noises ignore it, but I'm **** and can;t have a gauge that does this crap.

 

[961500]

The pump is not hard to do it's the crap you need to remove to do it. On the vortec motors the timing cover has a lip that seals the oil pan so both have to come off along with accessories. It took me about four or five hours to do the pump and bs by myself. Now if someone here has a trick to the pan timing cover crud hopefully the will
rise up. Good luck on it you can by a new oil filter
plenum with the valve it's a simple bolt in to try first.

 

[retorq]

More then likely a gauge or wiring issue. If you TRULY had 0 pressure at idle and only 5 - 10 driving your engine would have had major issues ...

 

[96_2DRSPORT]

i love this forum because i am having the same problem !!!!!

 

[slingblade]

The pump is not hard to do it's the crap you need to remove to do it. On the vortec motors the timing cover has a lip that seals the oil pan so both have to come off along with accessories. It took me about four or five hours to do the pump and bs by myself. Now if someone here has a trick to the pan timing cover crud hopefully the will
rise up. Good luck on it you can by a new oil filter
plenum with the valve it's a simple bolt in to try first.

Does the harmonic balancer have to be removed? And did you have to drop the axle to get the oil pan off?

 

[Da90]

The pump is not hard to do it's the crap you need to remove to do it. On the vortec motors the timing cover has a lip that seals the oil pan so both have to come off along with accessories. It took me about four or five hours to do the pump and bs by myself. Now if someone here has a trick to the pan timing cover crud hopefully the will
rise up. Good luck on it you can by a new oil filter
plenum with the valve it's a simple bolt in to try first.

Not correct I changed the oil pump in mine about month ago hoping it would solve my knocking/low oil pressure problem. Ended up being a wrist pin anyway... All you have to do is take off the plastic part on the top of the motor that says vortec, take out motor mount bolts, jack up motor. There is a wire that runs along the crossmember that will need to be disconnected also. Then once jacked up just remove the oil pan. No removing the front accessories at all. Once off you will have 2 bolts on a pan if I'm remembering correctly and also 2 bolts also in the acutall pump. It's easy and takes about 2 hrs. Oh yea might as well replace the gasket while your there also. One more thing the oil pump has a 2 piece rod that has a plasic clip on it be sure and buy the replacement that has the metal clip.

 

[faze]

Were it me, before I dropped the pan, I'd pull the sending switch out and put a mech gauge on it to see what the real pressure is.

I've had the guage set go on a 95 and it started with the op guage and then went into the volt meter...both began reading incorrectly.