Turncoat_Reno
NAXJA Forum User
- Location
- Reno, NV
So after a little bit of research, I've come to believe that my oil pressure sending unit may have started to fail after about 200k miles. Mostly I'm just looking for a couple of opinions as to whether or not that's a good assumption.
Symptoms:
I've had my 89 xj (4.0l, ax15, np231) about a year, not too many problems so far. It was very well maintained by the previous owner who had it from 50k-200k. In my experience this last year, oil pressure runs between ~40-50psi cold, and ~20-40psi after long drives (25+ minutes), never goes any lower than that. Just changed the oil a few days ago, and it's been running a little higher, about 45 to 55 or 60psi, but I haven't really gone anywhere to get it warmed up good (I live about 1 mile from my job, just been driving home and back since I changed the oil on Wednesday 5/2).
Driving home today about 25mph I looked down and noticed the pressure read 80psi. I took my foot off the pedal and it fell to 50, hit the gas barely (~1.5k rpm) and it jumped to 80 in a couple seconds. Driving down the street it seemed to jump around randomly a few times, up or down 10 or 15psi at a time. Most of the time it would respond to me revving the engine (up when I revved it, then fall back down when I took my foot off), but sometimes it would just stick at one pressure for a moment.
I got home, turned it off for a minute, then restarted it. I let it run for a minute or two and it sounded normal (some lifter tick, but no different than its sounded since I've had it, they go away mostly after 5-10 minutes of driving). Pressure read 40psi, when I hit the gas it went up to 60psi, but never higher, even at 4k rpms.
I've looked at a bunch of posts, and they've pointed me toward the oil pressure sending unit. My gauge has always read 0 when the engine is off to my knowledge, but it read about 5 when I put the key to accessory while testing this hypothesis. I didn't move with or without the key in the ignition, just sat about 5 until I started it again, then it went up to 40ish. Also, I noticed 2 or 3 very small drops of oil on the ground when I got home, looked like they'd dripped off the starter. I read in one post that when the OPSU fails, it can leak some oil out the end where the plug connects. Does this seems likely at all?
My other thought for the high pressure was clogged oil passages, although the oil has been changed regularly by both me and the PO, and I didn't notice any different sounds from the engine to indicate something not getting oiled correctly.
Does it sounds like I'm heading in the right direction?
Thanks for reading all of that, any opinions/comments are welcomed. :wave1:
Symptoms:
I've had my 89 xj (4.0l, ax15, np231) about a year, not too many problems so far. It was very well maintained by the previous owner who had it from 50k-200k. In my experience this last year, oil pressure runs between ~40-50psi cold, and ~20-40psi after long drives (25+ minutes), never goes any lower than that. Just changed the oil a few days ago, and it's been running a little higher, about 45 to 55 or 60psi, but I haven't really gone anywhere to get it warmed up good (I live about 1 mile from my job, just been driving home and back since I changed the oil on Wednesday 5/2).
Driving home today about 25mph I looked down and noticed the pressure read 80psi. I took my foot off the pedal and it fell to 50, hit the gas barely (~1.5k rpm) and it jumped to 80 in a couple seconds. Driving down the street it seemed to jump around randomly a few times, up or down 10 or 15psi at a time. Most of the time it would respond to me revving the engine (up when I revved it, then fall back down when I took my foot off), but sometimes it would just stick at one pressure for a moment.
I got home, turned it off for a minute, then restarted it. I let it run for a minute or two and it sounded normal (some lifter tick, but no different than its sounded since I've had it, they go away mostly after 5-10 minutes of driving). Pressure read 40psi, when I hit the gas it went up to 60psi, but never higher, even at 4k rpms.
I've looked at a bunch of posts, and they've pointed me toward the oil pressure sending unit. My gauge has always read 0 when the engine is off to my knowledge, but it read about 5 when I put the key to accessory while testing this hypothesis. I didn't move with or without the key in the ignition, just sat about 5 until I started it again, then it went up to 40ish. Also, I noticed 2 or 3 very small drops of oil on the ground when I got home, looked like they'd dripped off the starter. I read in one post that when the OPSU fails, it can leak some oil out the end where the plug connects. Does this seems likely at all?
My other thought for the high pressure was clogged oil passages, although the oil has been changed regularly by both me and the PO, and I didn't notice any different sounds from the engine to indicate something not getting oiled correctly.
Does it sounds like I'm heading in the right direction?
Thanks for reading all of that, any opinions/comments are welcomed. :wave1: