Oil problem ongoing for about a year

[trad016]

I have a 2001 TJ 4.0, I-6. About a year ago, I started overheating and losing anti-freeze. I could not find a leak. I changed the thermostat twice and water pump once And both large hoses and clamps. Still losing coolant, but only after using the heat. A short time after it started overheating, I noticed my oil pressure going to zero at idle once I reached 210 degrees (operating temp). In order to get oil pressure, I have to rev the engine past 2000 rpm until it reaches 20 psi. Then it will hold until I go below 900 rpm. I changed the pressure sensor and sending unit. Didn't fix it. I thought maybe a head gasket or cracked head, but I am not losing oil and I don't have milkshake oil. I did notice dirt in ther oil a while back, but I fixed that when I changed the oil pump and strainer. About 2 months ago, I had the #4 push rod come off the rocker and the rocker was loose. I made sure the rod was straight and reinstalled it. I also checked torque on all the rockers. I still have a slight click at idle, but I think that is just wear. Today, I looked and the cam shaft position sensor and noticed significant wear on the blade and on the gear teeth. Would this possibly cause the problem? I also noticed some moisture from the tail pipe. It has no odor, so I didn't think it would be coolant. I've been getting frustrated for a while now, but I am determined to figure it out. Any help will be appreciated.

[fredjacksonsan]

How many miles and have you ever changed your coolant? If not and over 50K I'd think your radiator could have a restriction in it. Once it overheated, it could have caused a head gasket failure. Wet tailpipe shows that something is coming out that isn't getting burned.

I'd check: radiator and head gasket. Maybe oil pump also.

[trad016]

I have just over 66000 miles. I have changed the oil pump. I have also changed the coolant several times and the water pump and thermostat. I just had the dealer look at it. I have a worn camshaft position sensor, but they were trying to convince me that I also "might" have a spun cam bearing causing the oil problem. How likely is this?

[fredjacksonsan]

Don't know about the bearing for sure, but it may be able to cause the problems you are describing. But having the dealer repair that problem will be expensive, especially if they "find" other things wrong. But since the pushrod came loose, you could have some internal damage that's affecting the engine.

With a new oil pump and still losing pressure at idle, there has to be somewhere that the oil is going. If it's leaking into your coolant and/or blocking the coolant flow, then that could certainly cause overheating, which is why I suspect the head gasket.

But again, I'd at least have the radiator checked.

Are you under the 7/70 powertrain warranty? If so you're in good shape, and tell the dealer to fix it all.

[trad016]

I really wish I was under the warantee. They started it 3 months after my purchase. I wondered about the leak, but I'm not having any change in oil quantity, I don't have smoke, and there is no indication of oil/coolant mix. I researched the bearing idea and found that the bearing has a oil passage hole in it that could block oil if it rotates. I still think I want to try the camshaft sensor shaft first, though. It's a whole lot easier to change. Thanks for your help.

[JDPascal]

On the cooling system - have you had the system pressure tested?? That should show any leaks. You can't see the heater but if the pressure tester is dropping, you can block the heater hoses with a clamp and see if the gauge shows that it holds pressure.

Also check the rad cap. That little piece is the unknown cause of a lot of cooling systme problems....

the moisture at the tail pipe may just be condensation. It should only be there while the engine is warming up.

The oil pressure concern is likely a separate problem.

If the cam bearing did spin and block the oil passage that shouldn't cause the drop in pressure at idle unless it totaly destroyed the bearing. Then you should have material in the oil pan and filter.

If the oil pressure is truly 0 at idle then the lifters should start to rattle after a time. Have you checked the pressure with a mechanical gauge?? Even with a new sender/sensor it is helpful to know the accuracy of the mechanical gauge will give you the true pressure.

JD

[89ltd]

I have the same problem with my 89, 4L, I am convinced it is a cooling problem. When I start the engine, the oil pressure is fine, as the engine heats up the pressure drops off, when it gets really hot, the pressure drops to zero as well. If it were the cam bearing, the pressure would be zero even when the engine is cold. I think the problem is completely concerned with the engine temp being to high.

[JEEP1997]

First I read, ABOUT A YEAR A GO you were, "OVERHEATING AND LOOSING A/F" -- WAY TOO LONG FOR THAT SITUATION TO BE GOING ON IN MY OPINION, but that's behind us now..... Before a year a go, did you then have oil problems? AND when you say OVERHEATING, what do you mean- steam blowing out the pressure relief cap or your gauge was showing above 220... Next question is what type of oil are you using/ grade of oil?? Typically, when you're losing coolant and NONE, can be found on the ground, there's not too many places for it to go but ONE-- in the engine and out the engine. I feel that is completely a head gasket, WHICH IS NOT THAT HARD TO REPLACED!!!!! And for the oil pressure, I would like to know how many times overheated means... Sorry for the questions, I just replaced my engine due to a knock, thinking first possibly a lifter- all changed-no help.. Pulled the engine, #2 Piston cracked below the wrist pin... Before I pulled it though, when she was cold about normal pressure, when it warmed up, Zero and idle and same thing with revving it up... What I suggest is to address the Coolant Issue First, then we'll tackle the oil pressure only after you change it! if you need to contact me directly, I'm Kevin at [email protected] I'm not a true motor head, enjoy helping others even if I'm not _____ Thanks for listening anyhow....