Whenever I'm driving, my oil pressure is ~40. But when I'm idling it drops to ~20.

I drive an '88 S10 Blazer. Worn main and rod bearings and crankshaft journals?

12/28/2005 1:56:17 PM

that's pretty normal

12/28/2005 2:05:30 PM

This is the stock gauge is it not? How do you know it's accurate?

12/28/2005 2:19:15 PM

^ possibility

12/28/2005 2:21:11 PM

I'd have to say it's normal as well.

Hell, I've driven vehicles with lower pressure at idle.

12/28/2005 2:25:35 PM

Regardless, I've seen a nearly brand new Avalanche have similar oil pressures as well as the camaro I used to have. It's not a problem. The old "rule" was 10psi per 1000rpm's and most agree even that is overkill

12/28/2005 2:25:53 PM

aight. i never look at that shit, but today when i was sittin at a stop light, the check gauges light started sporadically flashing, like there was a bad connection or something. it stopped when i hit the gas, but i started payin attention to the gauges and noticed this.

12/28/2005 2:28:33 PM

if that is coming on because of the oil pressure then it may be a problem then...if you actually had 20psi of oil pressure i doubt the light would come on though. i know on my 3000GT it came on around 12psi

12/28/2005 2:30:21 PM

20 psi at idle when fully warmed up is not low

12/28/2005 6:49:30 PM

which engine do you have?

thats about dead on for the 2.8, dont know about the 4.3 though

12/28/2005 9:04:37 PM

thats how my 4.3 astro was

12/29/2005 3:06:26 AM

run some 10-40 or 20-50 in there, or put in an oil pump, bout your only options with a chevy

12/29/2005 7:25:22 AM

why? 20 psi is fine

12/29/2005 8:26:27 AM

oh yeah...its a really great idea to fill it up with 20-50 right in the middle of winter

12/29/2005 5:23:21 PM

Quote :

"oh yeah...its a really great idea to fill it up with 20-50 right in the middle of winter"

oh yeah...its a really great idea to run your engine with a worn out pump and no thin ass oil getting to anything any time of year

12/29/2005 8:03:17 PM

oh yeah, 20 psi is not low

12/29/2005 8:34:22 PM

hey when i get off the highway in the olds my oil pressure is about 15psi, and thats within spec. its more important that the pressure remains proportional to rpm.

12/29/2005 8:43:23 PM

Quote :

"oh yeah...its a really great idea to run your engine with a worn out pump and no thin ass oil getting to anything any time of year"

you're obviously a dumbass if you think putting in a thicker oil is gonna improve things...yeah making the "worn out pump" work that much harder to pump a thicker oil through the lines and filter, especially at start-up, is DEFINATELY gonna help out

12/29/2005 9:19:29 PM

i'm running 20-50 and a quart of lucas in my 400 smallblock powered s10 just to keep any oil pressure... it has ~20psi cold idle, dosen't register on the gauge at hot idle
and about 25psi at 5500 hot

this motor has been running like this for a long time... no problems

[Edited on December 29, 2005 at 10:39 PM. Reason : ]

12/29/2005 10:39:11 PM

^^ who is this fucker and what is he doing in the garage? and do you even know the priciples of a positive displacement pump? compresibilty? viscosity? reynolds or prandtl number or even laminar vs turbulant flow for that matter? in a nutshell for fucktards like you, a higher viscosity oil will allow for much higher shear without cavitation, allowing larger clearances, (ie a worn out pump in fucktard language) to produce more pressure and in this case volume of flow to the top of the engine, whereaes a thinner oil will only make it in sufficient quantity to the mains and rods, and possibly the cam, no its not and end all fix, but it will prolong the engine until correct repairs can be done.

[Edited on December 29, 2005 at 10:44 PM. Reason : slow on the trigger]

12/29/2005 10:44:09 PM

please...spit out more fancy vocabulary trying to make me look like a dumbass when you arent exlpaining a damn thing in relation to what i'm talking about

now try again...

Quote :

"oh yeah...its a really great idea to run your engine with a worn out pump and no thin ass oil getting to anything any time of year"

Quote :

"yeah making the "worn out pump" work that much harder to pump a thicker oil through the lines and filter, especially at start-up, is DEFINATELY gonna help out"

to add to this so overly intelligent dickheads understand my point...

on a "worn out pump" i would assume it is worn as a result of high mileage...in this case the working parts are more than likely going to be fatigued, not to mention the pump seals are probably going to be worn as well. Granted the high viscosity oil might help to prevent seal blow-by, if they are too weak it will just blow out over a period of time, short or long. Then providing the seals hold tight, and it can produce these high oil pressures you got such a hard on for, you just hope the pump can handle it and doesnt decide to just shit the bucket (pump failure) instead.

oh yeah.....



[Edited on December 29, 2005 at 11:21 PM. Reason : .]

12/29/2005 11:19:29 PM

^^ look professor we dont need that shit.

12/30/2005 3:08:16 AM

I never knew an oil pump on an engine to have seals.

Pump wear is usually between the gears and the housing, or between the outer rotor and inner rotor on a gearotor or trochoid pump.

Thicker oils actually pump better and more efficiently in worn pumps because they don't bleed past the excessive clearances as much. That's one reason why cold oil pressure is so much higher than hot oil pressure in an engine, especially a worn one. The oil is thicker when cold.

A lot of modern lubrication systems have a bypass valve that actually bleeds off excessive pressure so that the oil pump never really sees excessive load, even with thicker oils.

12/30/2005 3:37:52 AM

^exactly

12/30/2005 7:25:23 AM

the cj usually has like 9 psi.

12/30/2005 8:25:43 AM

as long as the lifters arent rattling, you're good to go

12/30/2005 4:03:21 PM

20 psi is straight for a chevy

12/30/2005 4:23:22 PM

well as long as we are throwing useless, non-pertinant info in here too, my 177,000 mile chevy 5.3 runs 35 a idle and damn near 80 at 2,500 rpm with 5w-30

12/31/2005 9:51:34 AM

^ I don't understand how any of you people can trust factory oil pressure gauges (this is a factory gauge right?). How the heck do you know it's really doing 80psi? That might be right, that might not be right. So how useful are these comparisons that people are making with their own worn the fuck out cars and in many cases 10+ year old gauges? That's all I'm saying. I don't see how useful this discussion is if everyone is going off questionable information.

My 1988 Rx-7 and my 1989 Supra both read around 20psi when warm at idle, but those gauges are extremely slow to respond to changes in pressure compared to my friend's aftermarket gauge. I don't really know wtf is going on when I'm actually driving it. Now my voltmeter on the 7 can be completely inaccurate at times, so how do I know my oil pressure gauge is any better? That's why I've got an aftermarket gauge ready to go in soon.



[Edited on December 31, 2005 at 10:07 AM. Reason : .]

12/31/2005 9:59:01 AM

for the record my guage and my engine have less than 5k miles

12/31/2005 10:50:38 AM