Just noticed on my 95 yj (2.5) the oil pressure gauge giving a low reading. It's usually just past 40psi while driving, now it's just below. When income to a stop it drops to below 20 sometimes all the way down. It seems to be running normal though. I'm thinking it's the sending unit from what i have read. Thoughts? Where is the sending unit located?
07-11-2012 11:13 AM
i have some what of the same problem. it could be a couple things
1. your oil pump/oil pump screen could be clogged or failing.
2.you could have a faulty sending unit.
07-11-2012 01:24 PM
the sending unit for the oil pressure, is located down on the passenger side of the motor, next to the oil filter. sometimes you can just take it out and clean it with some carb cleaner, make sure you use thread tape to put it back in. other times its just the connection of the wire on top that needs cleaned and adjusted.
Or it needs replaced.
But dont be surprised if you put a new one in and get the same readings. The guages in a YJ are noted for being good for awhile then they do their own thing, sometimes they work others they go on vacation or something...lol
Good luck guys.
07-11-2012 02:27 PM
Not sure how many miles you have on it but if the pressure is higher when its cold then drops a lot lower after it warms up, it could be worn bearings. Not to worry you or anything, but if a new sending unit doesn't change anything, you may want to consider going to a high volume oil pump as a band aid alternative to a motor rebuild if the bearings are worn.
Just something to think about.
07-11-2012 07:46 PM
The engine is rebuilt with the mileage unknown. From what ive gathered I would guess it has less than 50k on it.When it starts it goes to around 40psi, then while driving it stays just below 40psi. When the clutch is pressed it drops slowly to around 20. Once on the gas it goes back to just below 40.
07-13-2012 10:43 AM
Mine is probably 20 PSI higher with the gas in it than it is at idle also. But my motor has 160k so I don't know if that's normal for the 4.2 or not. I just replaced the oil pump and I get higher oil pressure but I still have the lower pressure at idle. So I don't think it's the pump.
07-13-2012 12:23 PM
Mine is normal idle at between 35-40, at speed its 40-55 depending on how cold the engine is. Mine had oil pressure issues and I pulled the sending unit, cleaned and reinstalled it, has worked fine every since. I assume you are not running synthetic, oil pressure tends to be lower overall with Mobil One and the like.
07-14-2012 08:24 AM
I think I found it. Just to the right of the distributor with 1 wire coming out if it . How does it come off?
07-14-2012 08:57 AM
Oil pressure sending unit socket ( like a deep socket), lefty- loosey/ righty tighty :-)