Oil pressure sending unit replacement?

[Rusty from Cleveland]

How hard is an oil pressure sending unit/sensor to replace on a 99 4.0L w/ auto. Just searched and saw where I need to do some troubleshooting 1st but the needle pegged out in startup just a few mins ago and it will not go off of 80 PSI unless I turn the engine off. Didn't look typical when it rose up either. Immediately went to 80 PSI versus the usual lag and then going up to 40-50 psi cold. No obvious indications of 80 PSI being an accurate measurement...Thanks....Good to be back on the list after a long vacation. No doubt this board is the best resource on the web for XJ...Amazing what kids can do to your leisure time.....Rusty

[jerrywagner]

5 minute job, near the oil filter, be sure to clean the threads and do not overtighten

[SteveT]

Be sure to get a sender for gauges, not an idiot light. They're not the same.

[Yucca-Man]

You didn't recently change the oil did you? A disconnected sender will immediately peg to 80psi as yours did. The sender itself is immediately above the oil filter, with a single (gray?) wire coming off the rear.

Jim

[Rusty from Cleveland]

Well, both Advance Auto and Autozone don't stock this item around here. Gonna have to check some of the mom and pop stores. Took a look at the sensor and as you all know it has a connector that I am not familiar with nor can I get my big head close enough to get a really good look at it. I prodded on it a few times, tried to pinch in in places where it looked like and should and was afraid that I would break it if I handled it any more roughly. Can you gimmie and idea of how to remove the connector so I can test my wiring so I don't waste $40+ on a new sensor. Hopefully I will not have to get this thing from the dealer as I am sure it would be a steal on their behalf! Anyone got a good enlarged pic of the sensor showing exactly how to remove the connector from the sensor? Thank you very much for all the good responses I have gotten so far. Oh, almost forgot...Not done a recent oil/filter change.....Rusty

[Rusty from Cleveland]

Let me clear this up a bit. What I see above the oil filter of my 99 looks like it has 3 wires running out of it. I hope I am not looking at the wrong thing since 1 of you mentioned on 1 wire and it being gray......Rusty

[JeffU]

The sender screws directly into the top of the oil filter base. It is also not un common for it to get broken when someone is in a hurry with their oil change and breaks it off removing the oil filter. (Yes I admit broke mine off once) . It should be available at any NAPA store. I think it was $30.00 bucks.

[scorpio_vette]

if you grab the oil filter directly at it's base and rotate your hand upward your wrist will hit a sensor directly above it. to disconnect the wire you have to VERY VERY VERY CAREFULLY pull up on a little clip that secures the connector to the sensor. just feel it out. yes i have broken the sensor off twice while rushing a 5 minute oil change and i also broke the clip off of my connector. but that's cuz i'm always in a hurry.

i've noticed that for some reason the "smaller" (not autozone, advanced, checkers) parts stores seem to carry that sensor more than the big named parts stores. napa will probably have it to.

hope that helps.

[Rusty from Cleveland]

Thanks guys!! What confused me was the use of wire versus wires going to it. I was looking at the right thing the whole time and verified it with a pic off of either Autozone's or Advance's website. That connector still looks a bit complicated, but I think I can manage it now and $30 from Napa sounds better than $40 and $50 from the others. Will see if the local Napa has it in stock....Thanks you all for your help....Rusty

[Rusty from Cleveland]

No one had it in stock that I could find. Best price was at O'Reily's for $26.99. Not too bad...Dealer was nearly $70...Everyone else was atleast $39. Easy install ince I figured out the connector clip....Rusty

[MAP]

I just had this same exact thing happen on my 99XJ about a month ago. The sensor is expensive. I haven't got around to replacing it. The pressure now reads a little lower than 80 but it is still high. The cheapest I saw was Rockauto.com.

I tried removing the connector and cleaning the contacts but it didn't help.
I know what you're saying regarding the connector.

The connector has this little red clip that you have to pull to one side before it will let the connector slide out. You need to use a small flat head screw driver to move the clip. Look at the connectors on your fuel injectors. The red clip works the same way. You need to move it to the side before the connector will pull out.

Good luck.
Let me know if you find a lower priced sensor. The Pre-96 sensors are much lower in price.

MAP

[otto]

Morris 4X4 has the 1998-99 unit for $31.95 online.


http://www.morris4x4center.com/chero...20Cherokee.htm

[ncwheeler]

Could a faulty sensor also be the cause of a very low and fluctuating(13-50psi) pressure reading?

[langer1]

Originally Posted by ncwheeler

Could a faulty sensor also be the cause of a very low and fluctuating(13-50psi) pressure reading?

Possible but not likely