K the chevy forum is down but i thought id ask. in my 94' silverado the oil pressure gage says when i come to a dead stop at a light or stop sign the oil pressure drops to the red line but as soon as i step on the gas it jumps back up. is the oil pump going bad? is the oil sencer gone bad? (the truck has oil)

 

Do you realize you are on a Ford Classic Mustang site?
I don't know much about Chevy engines so can't even attempt to answer your question. I may have to move this thread if nobody else has a viable answer for you.

 

ah i know the fullsizechevy forums been down otherwise i would have posted it on there but thought i give it a try

 

I do know that if it was a Mustang engine I would be concerned about the low pressure at idle. The Ford engine needs about 10 lbs. of pressure for every 1000 RPM. So at idle the pressure should certainly not be 0. It should be about 8 or so. Running at 70 MPH, you should be running between 30 and 40 lbs of oil pressure. Now, remember, this information is about a Classic mustang engine and not a 90's chevy engine so it may not be correct information for your application. If you are running at 0 at idle, I would relplace the oil pump.

 

I have a 92 siverado with a 350..or 5.7 ltr for you metric buffs.
I run about 10 Lbs at hot idle.
30 Lbs cold
68 Lbs @ 3000 RPM
What kind of gauge are you reading...it an electrical gauge?...or is it mechanical...
If it is electrical, I would get a mechanical gauge and correlate the readings before you waste time changing oil weights, or pricing oil pumps.

 

It sounds like it could be a partially stuck pressure bypass. Your psi is definately too low at idle if it's dropping to 0, but if it comes up quickly to where it needs to be the the pump is prolly ok, but the bypass is partially stuck, and it doesn't close back when the pump slows back down to maintain proper pressure. If it is then you'll prolly have to replace the pump, since the bypass is generally built in to the pump...though it may not be, so you'll have to find out for your truck, it might have a seperate bypass that's not in the pump. It could be a sensor too, so you could try changing it and see if it fixes it(but don't drive that truck to the store to get it!)

 

See what ya get for driving a chevy ...sorry someone had to say it

 

I had a 74 grand torino way back when i was 16. It had the same symptoms you discribed. It was a pump going bad.

 

How's the oil level? If not that, then you have either a bad pump or worn bearings.