loss of oil pressure?

[96ProCompTahoe]

on the drive home i noticed the oil pressure guage dropped from its normal 50ish to 40, and when you let off the gas just above 20. no coolant in the oil, no loss of oil, trucks not running any different that it was before the pressure dropped. no noise, nothing.

so how likely is it that i have a bad oil pressure sending unit? i ask because when i first picked it up is was still pushing 60 as many have stated their vortecs run at, then it dropped to 50 after an oil change, and stayed there for the last year or so. and if it could be the sending unit where is it?

or am i pretty much screwed and looking at a rebuild? 96 tahoe with just under 170K on the clock. if im looking at a rebuild what can i expect to pay a shop to do it? the tahoe is (or was) the only reliable vehicle i have at the moment and time is a major factor.

 

[96ProCompTahoe]

alright, did some searching online, and it seems it could be bearing wear, causing the loss of pressure, but would it happen all at once or would it slowly happen over time?

also read that if it hits below 15 the computer will kill the truck so it won't run on to little pressure? is this true on my 96? would atleast be reassuring that i couldn't completely smoke the engine.

 

[mygreen98]

mine does same exact thing. been doing it for at least a year now. 20 psi is as low as it goes. never any noise. i've put a little heavier weight oil in it, helped a bit. no problems at all. over time bearing wear causes a slight drop in pressure. when it gets too low the engine light will come on. i'm dont think truck wont run though. i wouldnt be alarmed. if you want you can replace oil pump to a higher volume pump,should add some psi. whats your milage?

 

[treepete]

hes about 170K..

I think that mine hangs out around the center of the gauge ( I think thats 40 on mine.) when Im on the pedal, its up in the 50-60 neighborhood, when I come off the pedal it drops down to the 30 neighborhood, then goes to 40 again...
Im not sure whats causing your problem.. it seems too sudden to be the bearings failing especially with no other symptoms.
maybe its just the sending unit. or just a one time weirdness..

well, sounds like you have some time if it IS the engine giving up its ghost.
nows the time to think of the crate 454. pull your outs, and plop in a new one. if your never going to sell it. do it up as right as you can with your budget.

 

[96ProCompTahoe]

i just can't understand why it happened all of a sudden. i just happened to look at it and see it slowly falling. i hope i'll go start it up and it will be normal, but if not was really hoping it wasn't rebuild time since i'm flat broke at the moment from buying a house.

was planning the 383 Stroker Drop in GM Performance engine whenever this 350 called it quits, but now it would just be a quick rebuild... (that or a rediculous Big Block, trans, and rear end swap if i ever "came into some money" haha)

 

[treepete]

hmm.. for me its normal for it to rise and fall with the pedal movement ( or shortly after actually) but I havent had mine drop waaay down like you said.
did you just start looking at your oil pressure gauge? I usually pay it no mind.

it was a fluke or a voltage weirdness hopefully...
did you big 3 your truck, or not yet?

is an oil pressure sending unit expensive? i cant say I've honestly shoped them.

 

[Scany]

when my bearings went out it dropped to zero and I got "Check gauges" along with unpleasant sound from engine.

With new engine my needle fluctuates somewhat depending on rpm and how warm the engine (oil) is. I feel that's normal. I think some of these speculations are the reason why my BMW don't have a oil pressure gauge, and the temp is programmed to stay in the middle, even if the temp varies somewhat. just so we wont worry about it

 

[96ProCompTahoe]

drove it to work, to lunch and home, and it stayed its normal around 40-50. on the way to work it actually stayed about 60 which hasn't happened for awhile. it has been really f-in cold around here lately, but that shouldn't have anything to do with it.

and it dropped while at a steady speed, and was already warmed up (on the gauge anyway) somehow i just happened to look at it at the right time.

guess i'll check into a sending unit tomorrow on lunch, if its cheap i'll go ahead and pick it up. install it before i tackle the radio that keeps cutting out and the driveline vibration in OD....

 

[vinmhslax15]

yeah my oil pressure gauge is messed up too
it kinda just goes crazy but it doesnt mean anything
ive had it checked out

 

[96ProCompTahoe]

yeah but mine doesn't go crazy all the time, this is the only time i've noticed it changing like that (and i tend to watch all of them more than i should. haha)

 

[sasquatch094]

quick question, what kind of oil and oil filter are you using?>??

 

[sasquatch094]

Reason why i say that is, i had a fram filter on my truck a while ago and the oil gauge would go nuts all the time. like fluctuate or something.. But idk i changed my oil and filter and its good now.. staying right in the middle.. beats me tho.. if you dont run your truck in a while, do you ever get any smoke when you first start it up??

 

[96ProCompTahoe]

valvoline high mileage 5w30 and a napa gold filter (same as what we use on all the cars sitting at the house and all my previous vehicles.)

it is about time for an oil change again. going to do that tomorrow if it warms up any...

truck never sits more than a day or two between getting driven. never any smoke. runs good and strong. it is due for a tune up, but then again that shouldn't have anything to do with the oil pressure.

Dude. don't EVER use FRAM filters...

 

[sasquatch094]

well yea, i took that bitch off when i saw the gauge going nuts.. lol

 

[vinmhslax15]

thanx ill ditch the fram

 

[Biggwaukegan]

gotta agree and say a great bigg f#^k:fu: fram filters...crappiest sht you can slap on.


Now then. I actually have this same issue except mine only dips to about 32 psi. Dont think its anything to worry about as long as no ticks and no smokie and no difference in performance. running the royal purple with a K&N filter and the beast love me for it!:Chevy::giggling:

 

[Whippled2dr]

Mine drops to a little below 30 when fully warmed up at idle and stays at 40 cruising around. I have 145K miles and use 10w30 Mobile1 with acdelco filter. Its normal, especially for my mileage.

 

[TahoeGoBoom]

ok, so after reading thru this, ive realized my truck is just weird. when i start it up it'll run at 60ish or above. when it warms up, it runs around 45. is high oil pressure an ok thing? lol