I bought my 4.0l Auto TJ Sport new in 2001 and have always taken good care of it. At 275K miles it has developed a bad rattle. Also, if it sits for a few days when I start it up it takes 5ish seconds for the oil pressure to build, long enough for the check gauges alarm to go off. Once the oil pressure builds it is rock steady.
From inside the jeep it sounds like a cat has come apart and the chunks are bouncing around. I took the Y pipe down and checked and all three cats are fine. I put the pipe back and started the engine and a loud rattle sounds like it is coming from the oil pan. It sounds like stones are tumbling around in there.
At 275K miles is it likely worn out rod bearings? I found a video DeXJs YouTube channel (Mastering The Diagnosis Of Noisy Jeep 4.0 Liter. Piston? Rod? Lifter? Flexplate?) where he has a 4.0L at similar high mileage and he opts to change out the rod bearings with the engine in the car.
The alternative would be to swap in a long block (from Frasier), which would be a lot more work and come in around $4K but would be more dependable.
Cheers...
From inside the jeep it sounds like a cat has come apart and the chunks are bouncing around. I took the Y pipe down and checked and all three cats are fine. I put the pipe back and started the engine and a loud rattle sounds like it is coming from the oil pan. It sounds like stones are tumbling around in there.
At 275K miles is it likely worn out rod bearings? I found a video DeXJs YouTube channel (Mastering The Diagnosis Of Noisy Jeep 4.0 Liter. Piston? Rod? Lifter? Flexplate?) where he has a 4.0L at similar high mileage and he opts to change out the rod bearings with the engine in the car.
- How risky is just swapping out the rod bearings?
- At 275K miles is it just worn out and a time bomb?
The alternative would be to swap in a long block (from Frasier), which would be a lot more work and come in around $4K but would be more dependable.
Cheers...
