I've been working on a 93 YJ project
for my daughter. After doing body/paint and mechanical upgrades, I decided I wanted to rebuild the tired 2.5 L engine, which had low compression in cylinder 1 and some piston slap. It has been a pretty good experience, except for the premium I paid the machinist. Yesterday, about 15 minutes into the engine break in, a loud knock (not tick) showed up. I shut it down, dropped the oil pan, and everything looked good (no metal). Given the oil pressure and temperature were good, I convinced myself that the knock was coming from somewhere else. Put in more breakin oil, and fired it up again today. It's definitely rod knock - loud, increases with load and acceleration, deep knock, coming from the bottom of the engine, ... Ugh. A brand new engine and all that work.
So, I guess I'll drop the oil pan again and see if I can detect any play in any of the rods and check the rod bearings. Any advice on something specific I should be looking for? Is it possible replace a bad bearing without pulling the engine, again. The machinist ordered my rebuild kit and told me they confirmed all the clearances. I'm not sure where I went wrong, or if it was their fault.
Live and learn ... the hard way. Thanks in advance for any feedback.
for my daughter. After doing body/paint and mechanical upgrades, I decided I wanted to rebuild the tired 2.5 L engine, which had low compression in cylinder 1 and some piston slap. It has been a pretty good experience, except for the premium I paid the machinist. Yesterday, about 15 minutes into the engine break in, a loud knock (not tick) showed up. I shut it down, dropped the oil pan, and everything looked good (no metal). Given the oil pressure and temperature were good, I convinced myself that the knock was coming from somewhere else. Put in more breakin oil, and fired it up again today. It's definitely rod knock - loud, increases with load and acceleration, deep knock, coming from the bottom of the engine, ... Ugh. A brand new engine and all that work.
So, I guess I'll drop the oil pan again and see if I can detect any play in any of the rods and check the rod bearings. Any advice on something specific I should be looking for? Is it possible replace a bad bearing without pulling the engine, again. The machinist ordered my rebuild kit and told me they confirmed all the clearances. I'm not sure where I went wrong, or if it was their fault.
Live and learn ... the hard way. Thanks in advance for any feedback.