Long story short. My brother turned 17 and I found him a 94 ZJ for $500. Absolutely Zero rust and Interior is a solid 8/10. PO originally said he bought it drove it home and let it set. It needed the tank dropped cause of bad gas. Well upon looking at the jeep I did my normal compression test the motor, verified spark and fuel. During that I got a whiff of the fuel and it was indeed getting stale. But it fired up and sputtered for a few seconds and died. I gave the man 500 cold ones and had the car towed to the house.
Fast forward. New gas filter and gas. Fires right up. Now I have a 02 TJ as a offroad daily. So I am highly aware of the 4.0 sounds. This ZJ sounded like a bad case of lifters and valve clatter. Checked, cleaned, soaked lifters, and re-torqued rockers. Not the problem. Now granted my hearing is really not the best but, It sounded more like Piston Slap or Rod Knock to my old man. Should have listened lol. But anyhow, played the which injectors kills the knock and its number 1 piston. Sent bore scope in from top and seen a nice piston skirt wear mark. Pulled the oil pan. Not a single flake but Number 1 bearing wasnt toast but it wasnt good.
Jeep has 230k miles but I swear the motor doesnt even have 10k on it. Hardly and grim and gaskets just look fresh. Im suspecting a a rebuild at some point and not a reman. I say that because the connecting and main bearings are Sealed Power. Not saying they couldnt have used them I just never have seen them used in a reman.
I've already tore the motor apart and its pretty dagum clean in there.
So to my questions
To me P1 bearing looked somewhat starved of oil. Oil press was good and had the proper amount of oil. This motor seems to be tilted towards the rear is this normal and is P1 starvation a issue?
Rebuilder didnt use Moly Skirt Pistons. I can see why Cant find any for a 94. Is there any known differences between the 96+ pistons? cause I can find them for days.
Thanks for the help gents, Ill throw some pictures up of the jeep and the motor later.
Fast forward. New gas filter and gas. Fires right up. Now I have a 02 TJ as a offroad daily. So I am highly aware of the 4.0 sounds. This ZJ sounded like a bad case of lifters and valve clatter. Checked, cleaned, soaked lifters, and re-torqued rockers. Not the problem. Now granted my hearing is really not the best but, It sounded more like Piston Slap or Rod Knock to my old man. Should have listened lol. But anyhow, played the which injectors kills the knock and its number 1 piston. Sent bore scope in from top and seen a nice piston skirt wear mark. Pulled the oil pan. Not a single flake but Number 1 bearing wasnt toast but it wasnt good.
Jeep has 230k miles but I swear the motor doesnt even have 10k on it. Hardly and grim and gaskets just look fresh. Im suspecting a a rebuild at some point and not a reman. I say that because the connecting and main bearings are Sealed Power. Not saying they couldnt have used them I just never have seen them used in a reman.
I've already tore the motor apart and its pretty dagum clean in there.
So to my questions
To me P1 bearing looked somewhat starved of oil. Oil press was good and had the proper amount of oil. This motor seems to be tilted towards the rear is this normal and is P1 starvation a issue?
Rebuilder didnt use Moly Skirt Pistons. I can see why Cant find any for a 94. Is there any known differences between the 96+ pistons? cause I can find them for days.
Thanks for the help gents, Ill throw some pictures up of the jeep and the motor later.