Hey guys I've had my xj for about 5 years now and within the past year my oil pressure gauge has been dropping to zero and showing a check gauges light when stopped while warm. My initial thought was the sending unit so i went ahead and replaced it. Same thing.

Since I'm a 2001 and 165k I know I have the bad head but I don't consume oil or produce sludge under the valve cover. What are some things I could do to narrow it down?

I run 10w-40 btw

 

I had a yj that did the same thing. I replaced the sending unit and put in a high volume
Pump.

 

My 2004 4.0 has had the exact same symptoms for years. Verified it with a mechanical gauge as 4psi at idle and 20 psi on the highway. I have learned to ignore it. If it wasn't getting lubed it would have blown up a long time ago! A high volume pump won't solve a thing other than maybe making the gauge read a little higher....the excessive internal leakage would still be the same.

 

OP, what brand of oil filter are you using?

FWIW, non-factory oil senders are quite failure prone and inaccurate.

Ever unplug the sender and caean the wire terminals in it and the plug?

 

so true one part that should definetly be purchased from the dealer. not much cost difference either. not saying that is your problem but it's definetly a good note to anyone else reading this thread

 

You won't use oil if you have a cracked 0331 head, but you almost always will use coolant. Are you having to add coolant to the coolant reservoir?

In general, I always verify suspected low oil pressure. Rent a mechanical oil pressure gauge from a parts store (call around for availability) and temporarily install it where the oil pressure sending unit resides. Compare those numbers to what you're seeing on the dash. Then you'll know for sure.

 

Good advice.....DO THIS FIRST. Been there done that. Also change oil filter. If your not using coolant and motor is not knocking (like mine) I would not be overly concerned as long as pressure comes up when rpm increases. Oil gauges can worry the hell out you...that is why Jeep went back to a fake gauge in 2003.

 

I do use coolant but i think my leaky heater core explains that (interior smells like maple syrup when heat is on)