Sporadic oil pressure

[avenged7foldhc]

soo the jeeps a little sick i guess.. back story:

back in probably july, the last time i had the jeep out wheeling. on a downhill grade at a funny angle was stopped for a while and idling. the oil pressure climbed a bit and then the bottom dropped out totally. immediatley i turned off the jeep and looked for any leaks, checked the level of the oil (after coasting to a level spot) and noticed nothing outwardly wrong..

when i started it back up it was back to normal, it happend one more time while on the trail that day but only bottomed out for a second before climbing back to normal..

the problem subsuquently went away, and i figured it was due to getting the sending unit wet or some such thing.


aaanyways i hadnt really driven it for a few weeks while at school (riding the bike everywhere) i brought it to pittsburgh for the weekend for guard.. anyways while sitting in traffic after the jeep gets hot, when stopped the oil pressure gague starts to climb, then bottoms out being in traffic i didnt want to turn it off so i gave it a little gas, and back up to normal, it will hold for a while before dropping again..

at regular cruising speeds it reads normal (just right of center where its been since i bought it) this has been happening for the past 2 days...

id immagine the cheapest route would be to just throw on a new sending unit and hope thats what it is. but was looking for any insight anyone might have. and if the sending unit is the case.. where is it?

one suggestion i had was to try out a mechanical sending unit first and see if it does the same thing, but i dont happen to have one handy..


thanks!

[DMG]

soo the jeeps a little sick i guess.. back story:

back in probably july, the last time i had the jeep out wheeling. on a downhill grade at a funny angle was stopped for a while and idling. the oil pressure climbed a bit and then the bottom dropped out totally. immediatley i turned off the jeep and looked for any leaks, checked the level of the oil (after coasting to a level spot) and noticed nothing outwardly wrong..

when i started it back up it was back to normal, it happend one more time while on the trail that day but only bottomed out for a second before climbing back to normal..

the problem subsuquently went away, and i figured it was due to getting the sending unit wet or some such thing.


aaanyways i hadnt really driven it for a few weeks while at school (riding the bike everywhere) i brought it to pittsburgh for the weekend for guard.. anyways while sitting in traffic after the jeep gets hot, when stopped the oil pressure gague starts to climb, then bottoms out being in traffic i didnt want to turn it off so i gave it a little gas, and back up to normal, it will hold for a while before dropping again..

at regular cruising speeds it reads normal (just right of center where its been since i bought it) this has been happening for the past 2 days...

id immagine the cheapest route would be to just throw on a new sending unit and hope thats what it is. but was looking for any insight anyone might have. and if the sending unit is the case.. where is it?

one suggestion i had was to try out a mechanical sending unit first and see if it does the same thing, but i dont happen to have one handy..


thanks!

The sender is on the right side of the block near the oil filter. They go bad all the time so I would replace it.

[steelhumm]

x2..my zj did the same thing as you described, easy fix.

[avenged7foldhc]

cool thx.. i went and bought one last night, well ordered it, picked it up today only 17 bucks (10 % military disc. yay) hopefully it fixes it..

now the jeeps got a little tap in it too.. gonna run a tank of gumout through it as its been sitting a lot. it hates me.. wobble is really bad now too.. found out the Drivers side rear was at 12 psi.. pulling hard to the left when i hit the brakes.. think the clutch might be going in it. 66k miles on the origional so it might just be in my head since everything else is going to shit town on a jet-plane..


*sigh* anyhows, i ll let yas know if the sending unit works

[avenged7foldhc]

soo i replaced the sending unit drove all the way to cal, stopped at the toll booth and the pressure went flatline. from the toll booth to cal everything back to normal until i hit the redlight in cal (about 5 miles) and flatline again..

so i guess its the pump which is total suck, being relativley broke and without another vehicle to drive (aside from the bike when its nice out).. the only other thing i can think to try first is changing the oil and filter again as the problem started the day after i changed it, and i went from using a PL14670 filter (purolator premium) to the L14670 (purolator standard) every change from 21k miles up to 65k ive used the PL but advanced was out the last time and got just the L.. either that or i got terds in the engine while wheeling it?

i did have a substantial stuck that day where it was pretty deep in some water for about 10 minutes or more, deep enough that i had to keep on the throttle to keep water/mud from getting into the exhaust.. probably only revved 1k 1.5k tops

[mudforblood]

I didn't read when the oil was changed last. Also what type of oil is in it?

The low oil pressure at idle and light noise would tell me to change the oil and run something heavier. The only thing that I don't get is why the pressure climbs before it drops. A spun bearing would do that but probably not more than once without a lot of noise. I run 15w40 in everything usually before the warranty is up to get a more constant oil pressure. Try that and see what it does before getting crazy with other stuff.

FWIW: I'd skip using gumout or anything similar until everything else is checked out.

[ArtCloud]

gary, mine did the same thing, it was the water proof connector that clips onto the sending unit, basically became not waterproof. anytime the engine got wet or very moist (wheeling, washing the jeep or very wet roads). It was covered under warrenty though and it only took about 4 trips to 3 rivers jeep / crysler to get it fixed.

[avenged7foldhc]

oil was changed at 65k its got like 1500 miles on it, using castrol syntec think its 10w30 (whatever the green cap is) every 3k since 21k (when i bought it)

i know worn bearings can cause the pressure to drop but theres no reason i should have bad bearings at 66k miles esp. with the way i treat the engine (rareley revved much over 3k)

the gumout is cause i had it sitting so long and it was running rough, havnt ran any fuel system cleaner thru it in a good while.

ill change the oil in er tomorrow and see what happens, go fer the 15w and make sure i get the 'premium' purolator..

[avenged7foldhc]

gary, mine did the same thing, it was the water proof connector that clips onto the sending unit, basically became not waterproof. anytime the engine got wet or very moist (wheeling, washing the jeep or very wet roads). It was covered under warrenty though and it only took about 4 trips to 3 rivers jeep / crysler to get it fixed.

yeah but its been dry for a few months :/

[ArtCloud]

True, might want to check the connector make sure the contacts are all clean and new dielectric grease and no loose wires?