I have a 2000 4.0. I have oil pressure issues. It likes to zero out on hot summer days (Florida) with the a/c at idle. Pressure goes back up when i apply throttle. Replaced the oil sending unit. Didn't help. I went to 20-50 and that cured the problem. Now its winter and i get some valve train noise on cold starts because of the thick oil.
So, anyway my next step to solving the oil pressure delima is the oil pressure gauge. I would like to install a manual gauge to double check my factory gauge. I bought a oil pressure gauge but i have no clue where to hook it up. Somewhere around the oil pressure sending unit? The gauge has a hook up on the back that looks like a place where a vacuum hose or something would hook up. I got it from China Freight http://www.harborfreight.com/mechani...ket-67016.html

 

I would not recommend a manual gauge, as they can make a huge mess of your cab, harbor freight carries electronic gauges for like $25. Buy one of those and use a t fitting to run both your stock and aftermarket gauges.

 

Where would i install a t-fitting at for a extra electric gauge? And what is a t-fitting? Where do i find one of those?

 

You would install it in the where the stock sending unit goes, then re attach the stock one and add the aftermarket one to the remaining spots. I think this would be an easier route for you though: http://www.glowshiftdirect.com/oilfi...5thread-1.aspx - this will install behind your oil filter and allows your to tap for an electronic oil press gauge.

 

I geuss I dont know how to use a drop down list, it didnt give me a jeep option.

 

The link was for example purposes, you have to find the right size thread then order it.

 

That's a awesome little device there. Definitely the way to install a oil pressure gauge. Hopefully my factory gauge is wrong and i can clear this up. My gut tells me my bearings are worn out from the 2000 head cracking. It eats coolant slowly maybe a half gallon in 2 oil changes. Just trying to do the cheap check stuff first.

 

The #1 symptom of a cracked 0331 head is coolant consumption.

If you are seeing a loss of coolant and you can't find a leak (after comprehensively searching for one), you might be one of the unlucky ones.

Pull the valve cover and many can see the crack or cracks between cylinders 3 and 4.

Good luck!

 

Yeah I've been in cracked head denial for a while now. Really clean XJ only 98k. All stock. Had this oil pressure problem since my first oil change. I love getting ripped off. Im pretty sure the head has a crack now that I've been through the forum a few times. Also that this crack has contaminated my oil and slowly ate my bearings over time causing my low oil pressure. So, i may be able to see this crack if i take the valve cover off? That makes me curious to see whats under there.