Oil Pressure problem
Thread Starter
Team Owner
Joined: Sep 1999
Posts: 41,732
Likes: 1,717
From: Springfield MO
Oil Pressure problem
I took my 98 out for a spin today and while sitting at a light the car acted like it wanted to die but corrected itself. Water temp was 145*.
I checked the DIC and the gauges and the oil pressure was at 19 psi. My normal pressure when the engine is cold is around 45 psi and the lowest around 26psi when the engine is 196* and oil temp is 205*. After the engine was at 196* the idle psi was the same and when I accelerated it very slowly went up to 28psi at 1200 RPM. At 2500 RPM the pressure was 32PSI. I've lost around 8-10 psi at idle and 12-15 psi at 2000RPM. The car only has 11,000 miles. If the car had always had a low oil pressure reading I wouldn't be concerned but to have a sudden drop worries me. I'm going to take it to the dealer but I suspect that they will say its within the normal range. I have 18 months left on my GM extended warrenty.Could a partially open oil pump relief valve cause this?
I checked the DIC and the gauges and the oil pressure was at 19 psi. My normal pressure when the engine is cold is around 45 psi and the lowest around 26psi when the engine is 196* and oil temp is 205*. After the engine was at 196* the idle psi was the same and when I accelerated it very slowly went up to 28psi at 1200 RPM. At 2500 RPM the pressure was 32PSI. I've lost around 8-10 psi at idle and 12-15 psi at 2000RPM. The car only has 11,000 miles. If the car had always had a low oil pressure reading I wouldn't be concerned but to have a sudden drop worries me. I'm going to take it to the dealer but I suspect that they will say its within the normal range. I have 18 months left on my GM extended warrenty.Could a partially open oil pump relief valve cause this?
Team Owner
Joined: Jul 2001
Posts: 21,335
Likes: 979
From: Various places in Southern California.
Re: Oil Pressure problem (JoesC5)
How old is the oil? In some cars I've noticed a drop in oil pressure as the oil gets older. (I haven't seen this with Mobil 1, though.)
Racer
Joined: Feb 2002
Posts: 299
Likes: 0
Re: Oil Pressure problem (JoesC5)
30psi here at idle with everything warmed up fully, 40psi running down the road at 2K rpm and 45 to 50 when she's cold. I've found oil pressure to run a bit low if I've been sitting in traffic when the temp climbs to 220 (at which point I kick on the air conditioning to engage the fans)... and will run a few pounds low until I turn her off and let it sit overnight -- at which point she has normal pressures the next day.
Try changing your oil. As it gets more miles on it, pressure seems to drop just a bit. My dealer uses Mobil One 5w-30, not 10w-30, in my C5. Seems to me 10w should be running a bit higher pressure because the viscosity is just a wee bit thicker.
Try changing your oil. As it gets more miles on it, pressure seems to drop just a bit. My dealer uses Mobil One 5w-30, not 10w-30, in my C5. Seems to me 10w should be running a bit higher pressure because the viscosity is just a wee bit thicker.
Burning Brakes
Joined: Aug 2000
Posts: 1,143
Likes: 0
From: Charlotte NC
Re: Oil Pressure problem (JoesC5)
About a month ago I experienced an 'increase' in oil pressure. I took it in for warranty service and the dealer replaced the sending unit which was defective. Just submitted for what it's worth.
Advanced
Joined: Nov 2001
Posts: 58
Likes: 0
From: Rincon Georgia
Re: Oil Pressure problem (Fang S-289)
my '98 did the same thing twice after the oil got alot of miles on it. i changed the oil and filter and the pressure went back to normal. i was also told that the sending unit could be defective or maybe something got in it and slowed the oil reading. it hasn't done it lately. good luck. :chevy
