Gromit
15+ Year Contributor
- 155
- 10
- Jan 24, 2006
-
metro-Detroit,
Michigan
OK, essentially I'm the original owner of this car - wife's car, which she got shortly before we met. 
In 15 yrs. of ownership, oil pressure on the stock gauge has always read roughly straight up/12:00 at idle or very low cruise & near the tip of the oil can at high RPM cruise. Car was completely stock until last year - mods are current in profile. Mileage is just over 90K - we drive it minimally & it has been babied. Compression test from 3-4 months ago was still near factory specs. Nothing has been done since an ECU swap this winter for an EPROM ECU & custom chip. 
Recently, the readings on the oil pressure gauge have changed. At idle, the needle drops very low in the 1st set of brackets. Pressure goes up with RPM's & sits around 12:00 or slightly higher at high RPM cruise. Right before this happened the 1st time, there was a small puddle of oil under the car - traced to a loose oil filter. Tightened that up & topped off. Oil level is good & no leaks. On 1st start, when cold, pressure reads like it used to, but then starts to drop after normal operating temp is reached. The oil pressure sending unit was replaced approx. 2 years ago - indications on the gauge at that time were different than this (no oil pressure was indicated at any time). Oil light does not illuminate, but does light up on start so it is functioning.
I have searched for topics about low oil pressure & also looked in our owner's manual - I see that this reading is, in fact, the normal range of operation. What I'm wondering is why has it changed now after 15 yrs. to what it supposedly should be?
Is there something else I should be checking? The search results don't seem to point to the pump as being an issue much, if at all. I did find some info on checking the pressure relief valve & I will probably do that next.
Any other thoughts/ideas/suggestions, or should I not be concerned?
In 15 yrs. of ownership, oil pressure on the stock gauge has always read roughly straight up/12:00 at idle or very low cruise & near the tip of the oil can at high RPM cruise. Car was completely stock until last year - mods are current in profile. Mileage is just over 90K - we drive it minimally & it has been babied. Compression test from 3-4 months ago was still near factory specs. Nothing has been done since an ECU swap this winter for an EPROM ECU & custom chip. Recently, the readings on the oil pressure gauge have changed. At idle, the needle drops very low in the 1st set of brackets. Pressure goes up with RPM's & sits around 12:00 or slightly higher at high RPM cruise. Right before this happened the 1st time, there was a small puddle of oil under the car - traced to a loose oil filter. Tightened that up & topped off. Oil level is good & no leaks. On 1st start, when cold, pressure reads like it used to, but then starts to drop after normal operating temp is reached. The oil pressure sending unit was replaced approx. 2 years ago - indications on the gauge at that time were different than this (no oil pressure was indicated at any time). Oil light does not illuminate, but does light up on start so it is functioning.
I have searched for topics about low oil pressure & also looked in our owner's manual - I see that this reading is, in fact, the normal range of operation. What I'm wondering is why has it changed now after 15 yrs. to what it supposedly should be?
Is there something else I should be checking? The search results don't seem to point to the pump as being an issue much, if at all. I did find some info on checking the pressure relief valve & I will probably do that next.Any other thoughts/ideas/suggestions, or should I not be concerned?
