02 KJ Liberty 3.7 Low oil pressure, two year old ticking sound

[BH1]

I got an 02 KJ with the 3.7 v6. It previously had a valve seat come loose and had a valve get stuck due to the loose valve seat. A refurbished head was installed a by a "reputable" engine rebuilding company. When the vehicle got back from the shop it had a ticking sound, the guys at the shop said it came from the gearbox. The vehicle was driven for the next two years without issues despite the ticking sound. However, in early 2023 the vehicle developed a misfire. The same shop diagnosed the car with low oil pressure and said that it could be a worn cam/main/rod bearing causing the oil pressure to drop. The oil is not milky but there is a loss of coolant and the expansion tank is low on coolant, I pulled the valve cover and found that one sparkplug has a milky rusty coating on it and a rocker was slightly loose. I tested the coil plugs with a multimeter and both the primary and secondary windings are within spec regarding resistance values. However there is steam coming from the tailpipe.

My guess is that it could be a blown headgasket/cracked head.

The ticking sound sounds like it is coming from the bottom of the engine, it would be a bummer if it is coming from the crankcase as we all know what that would mean...
Could it be a timing chain issue or a lifter tick ?

I am familiar with working on cars as a DIYer, my first starting point would be to do a compression test to diagnose whether it is a headgasket/cracked head/stuck valve or all 3...Through this. I will also know which bank has the issue.

Any suggestions from the forum members ?

 

[KJowner]

Does the tick go quite when you're coasting? Is it quite until the engine warms up or louder until its warm?
Is the noise there in park or neutral?
Timing chains usually make a light rattling noise, especially on tickover.
Valve train noise is normally very obvious around the rocker box cover.
I think you are right about the water leak, head gasket or head, with steam and a rusty plug it's fairly clear where that problem is.

 

[BH1]

The tick is noticeable at idle and when revving the car in Park position. I have not driven the car on the road for a while, if I can recall correctly the sound disappears when I am coasting. I pulled the car out of the garage yesterday and I recorded the ticking sounds, I tried to attach the video onto my post but I see that it does not allow Mp4 files to be attached.

The Low Oil pressure light is on and there is some moisture/steam coming out of the tailpipe.
I will fix the head/headgasket but I'm concerned that the ticking sound may be a bearing knock, it was there since 2021/22. The vehicle went off road with this noise present, since appearing the sound has not gotten any louder, it remains consistent.

I am also considering doing an oil analysis to determine if there are bearing metal particles present in the oil, this would prevent me from stripping the motor.

I can work on the car myself in order for the numbers to make sense, but I am reconsidering it because these 3.7's have recurring issues e.g. Headgasket,valve seat issues.

The rear passenger side window regulator broke that plastic attachment off, the blower resistor motor is faulty and the ball joints need to be replaced. There are new KYB shocks and struts on. All the issues are typical issues which can be sorted.

An Isuzu Trooper was going to replace the Jeep, but I am thinking that I can just keep the jeep and do all the work myself whenever problems arise and moreover to save money. Perhaps I will become an expert at fixing this jeep and it will make everything easier for me in the long run? It is quite fun off road and I would install a rear locker at a later stage if I keep it.

Should I fix the car or get rid of it ?

 

[BH1]

It also has a faulty ignition switch actuator pin, I can get one off Rock Auto.

 

[derekj]

Before doing anything I would put an oil pressure gauge on it to see if it is just a faulty sensor or if it actually has low oil pressure. If it does have low oil pressure, and combined with the possible head gasket leak I would be looking for a new motor and not wasting time/money on this one.

 

[BH1]

Before doing anything I would put an oil pressure gauge on it to see if it is just a faulty sensor or if it actually has low oil pressure. If it does have low oil pressure, and combined with the possible head gasket leak I would be looking for a new motor and not wasting time/money on this one.

That crossed my mind when I was brainstorming possible causes. The oil pressure light did not go on when the engine first misfired. The guys at the shop performed an oil pressure test and told me that it was low, however the warning light was not on, it only illuminated after the car was parked for a few months. It has since remained on. It is possible that the connector may be damaged because the guys at the shop removed the sensor to do the oil pressure test, that connector can break very easily. I was thinking of testing the oil pressure sensor with my multimeter, It is a 3 pin sensor. I need to find out what the resistance values are expected to be for an operational oil pressure sensor. I don't have my own oil pressure tester so I can't perform the test again. But I will need to test the sensor itself.

 

[BH1]

Apparently the best way to remove the sensor is to remove the cooling fan and then work your way in from the top of the engine bay. I don't have a lift and working from the floor could be a serious pain.

 

[ltd02]

If you do change the sensor, make sure you get one for a switch not a gauge.

 

[derekj]

That crossed my mind when I was brainstorming possible causes. The oil pressure light did not go on when the engine first misfired. The guys at the shop performed an oil pressure test and told me that it was low, however the warning light was not on, it only illuminated after the car was parked for a few months. It has since remained on. It is possible that the connector may be damaged because the guys at the shop removed the sensor to do the oil pressure test, that connector can break very easily. I was thinking of testing the oil pressure sensor with my multimeter, It is a 3 pin sensor. I need to find out what the resistance values are expected to be for an operational oil pressure sensor. I don't have my own oil pressure tester so I can't perform the test again. But I will need to test the sensor itself.

I don't know where you live, but maybe one of the bigger auto parts stores in the US would rent you an oil pressure gauge - they are also pretty inexpensive to buy - $25 on amazon. That's where I would start...

 

[KJowner]

An engine tick that disappears on coasting isn't a good sign, sounds like a big end bearing, that would tie in with low oil pressure.

 

[BH1]

Update:

1) I did a compression test, see results below.

Cylinder 1 - 35 psi
Cylinder 2 - 160 psi
Cylinder 3 - 140 psi
Cylinder 4 - 140 psi
Cylinder 5 - 140 psi
Cylinder 6 - 160 psi

I am assuming that I have a blown headgasket given that there is at least some compression in cylinder 1 and not zero compression which would have meant a loose/broken valve seat or a bent valve.

2) I discovered that the 3 pin female connection on the oil pressure switch broke off, I am assuming that the guys who previously did the oil pressure test at the shop broke it off, it is in a hard to reach spot so they might have tried to use excessive force. I believe this is the reason why the oil pressure light went on. I purchased an oil pressure test kit, but I did not do the test yet. I will see if I have time to do the test in the new week, it is a hard to reach spot especially considering that I don't have a lift.

3) The ticking sound from the lower part of the vehicle is most likely a loose bolt on the torque converter or flex plate.

Do I have to remove the engine to tighten bolt/s on the torque converter or the flex plate ?


4) I will replace both headgaskets while I am in there, the headgasket will be sourced on Rock Auto. I will also replace the water pump, thermostat, expansion tank cap, the oil pump and I will clean the oil pick up tube screen.

 

[ltd02]

I would still recommend actually measuring the oil pressure. Those Mopar dummy lights don't tell you much. I had a rod bearing go out in my 02 and it was not a tick. It was a very obvious knock. Eventually it spun and the motor seized.
Low compression on one cylinder to me could be a headgasket but where is the compression going? Is your coolant "boiling"? Could be a valve seat or piston rings. Just had this same thing on an old pontiac. Ring grooves broke. Wouldn't hurt to at least pull that one head.

Do you have a borescope?

 

[BH1]

I did an oil pressure test, the results were as follows:

1) Cold Idle: 65 PSI (Workshop manual states: 4 PSI)

2) @3000 RPM: 80 PSI (Workshop manual states: 25-110 PSI)


So it appears that there is high oil pressure issue on idle.

Current Oil is Shell helix HX8 5W40.


The car has a history of irregular oil changes.

Stuck oil pressure relief valve on idle due to sludge build up or a foreign object ?

Could this be the cause or a result of the headgasket issues ?

 

[KJowner]

The manual can't right, 4 psi at idle is nothing, it would wipe the crank out on tickover! 65 psi cold sounds like a normal pressure on startup. Warm oil pressure is more important, when the oil is hot the viscosity drops, I'd repeat the test with the engine at operating temperature.

 

[BH1]

Okay, I will idle the vehicle for a few minutes with the OBD scanner plugged in so that I can monitor the coolant temp until it reaches operating temperature.
I will idle it with the oil pressure tester in. Once it reaches operating temp, I will switch the car off and release the pressure from the gauge and restart the engine to get the warm idle pressure.

Below is what the manual states.

You must be registered for see images attach

 

[BH1]

Oil pressure update:

20 psi at idle, coolant temp 78 degrees Celsius.


I believe this is within spec.