strange engine problem

[lethaldose]

ok today normal driving about 20 min trip my oil pressure hangs around 40-60 and my temp sticks around 160-180 alls well ... i turn off the jeep for maybe 6 mins crank it back up seems kinda hard to start but i'm like ok ... oil press is bottomed out check gauge light came on so i give it a lil juice and it brings it up in about 10 secs so i'm like odd but keep going .. but anytime at idle PSI goes to 20 ... and my temp gauge was floating at the 200 mark and eventually 210+ just around town puttin ... so i whip in to ADV check make sure my fan is running then turn it off check oil level which is fine .. check coolent level fine .. check for leaks or drips naDa... so i'm still like WTF ... so i fire it up pressure is bottomed at 0 so i dont give it any gas stays at 0 with the check guage beeeeeeeeeeeppppppp so finally i juice it and back out goes up then floats back to 20 at idle or real low RPM's heat is still 200-210 i get it up to freeway speed about 55 temp goes back to normal oil is 40 as soon as i start up hill heat goes back up at idle oil is back to 20 psi ? .... does anybody have a clue ??? just to give me a heads up i know i wrote a book here but i'm gonna rip into it tomorrow just like any extra you guys can give ... its 2001 4.0 thanks :?

 

[lethaldose]

ok nobody's replied yet but anyway and update ... i turned her off ... sat for ohh say 2-3 hours cranked it back up ... BOOM like new everything reads fine oil pressure 35-40 idle 40-50 running temp fine ... so what gives ?? wire prob ??

 

[TwistedCU]

210 isn't really high for a 4.0L.

As for the oil pressure, Idle at 20 isn't bad at all, but zero... not good. The check engine light came on? Go to Autozone or the like to get the codes checked.

 

[lethaldose]

no check guages light came on ... just lights up and beeps until the pressure goes up ... with my 4.0 i've never had under 35ish usually hangs at 40 lil under and under a load 40-60 ... temp stock is 210 but i have a 160 stat and a 2500CFM electric fan on it and on a trail NEVER had over 200 and thats crawling

 

[mud4feet]

Maybe a bad sending unit?? Just a thought, and they're not too expensive to replace. Doesn't explain the temp thing, though.

 

[lethaldose]

yeah i read somewhere they are bad for sending units but everything has oddly enough seemed to work itself out with no problems today at all during daily driving... i do have an odd whuuurrr noise that gets progressive in loudness with engine RPMS but i think its the tensior and idler pulley