My oil pressure reads around 70 to 80 on the gauge cluster, I have not drove my jeep that much in the last 6 months and the last owner did a oil change right after i bought it 6 months ago (part of the deal) im wondering if he put "too thin" of oil in it. ideas?
87 jeep cherokee

 

Most likely, you have a faulty oil pressure sending unit, or someone installed a "switch" type sender that is supposed to be used with dummy lights and not guages...
Too thin an oil would have the opposite effect.

 

The odds are very high that the oil pressure sending unit is faulty.

It is a VERY common failure on the 4.0 Jeep engine.

I recommend that you buy a replacement MOPAR unit. Aftermarket units are hit and miss.

Be sure to keep us updated!

 

argh, alright. will have my bro order me one in the morning "works at a autopart store" TY guys

 

Along with the sending unit take a peek at that filter. If the PO did an oil change for you I doubt he spent that much... a collapsed filter can mess with your oil pressure. If the filter is orange with bedliner on the end swap it out anyway.

 

I did LOL on that one, yeah it does. i have everything to do a oil change sitting right next to me. with a prem. filter and it's not orange. I did not put 800 miles on the jeep since ive bought it but im going to start using it as a daily driver when the snow starts falling and that's one of the things I "HAVE" to change before i start driving it that often.

"If it's the guarantee that you want, I'll take a dump in a box and slap a guarantee on it".

 

Update:
just got done with my oil change, at 1st it went up to 80, then went right down to the 40 range has not gone back up after a 20 min drive,

 

May not be the sending unit. My 90 reads the same at idle upon startup 60 to75lb, drops to about 40 once warm. thought it was wrong got a new one no change, verified it with a manual gauge read the same. Chrysler said that that was normal.

 

You may still want to pull the oil sending unit to check and see if you have some sludge building up in the orifice . That can cause it to rise and return to normal one the oil heats up and thins out.

 

I replaced my sending unit today. I was experiencing 40-45 psi at startup and above 2000rpms, 10-13 psi at hot idle. Now I'm getting 55psi at startup and above 2000rpms and 20 psi at hot idle. Nothing else really to say, I suppose this isn't conclusive since I haven't manually confirmed the pressure.