A little background- At the end of last mowing season my 1991 toro groundsmaster 322-d (has a mitsubishi k3d 3 cylinder diesel engine) lost compression on #3. Checked valves, all good. So I am just tonight finishing up the repair (all new rings and rod bearings) and testing it out.
Heres where it gets strange. Testing cylinder 1 I get a perfect of 455 psi. Good. Cylinder 2, 700 PSI!. Thats 245 pounds over spec. And number 3 still has zero. I can't figure out for the life of me what is going on. Im scared to keep testing it with such high compression in that cylinder.
There were a few odd things I noticed when I had it apart too. First, the number 3 rings looked fine. Very little wear and certainly nothing that looked like it would cause zero compression. The top ring on the #2 piston, in fact, was broken. Second, the number 1 rod bearing was completely gone. I had to have the crank journal refinished and use undersize bearings because the scoring was so bad. I collected the shredded bearing from the oil pan. The others were fine.
Does anyone have any idea what might be going on here? I'd greatly appreciate any input.
*Edit- Also, the number two bearing had spun.
UPDATE: The zero compression on number 3 was a result of bad valve adjustments that got messed up when I pulled the rockers. Compression on cylinders 2 and 3 are now around 600 pounds. Still high, but they both run. It now seems that i am back to my original problem, but now it has moved over to cylinder 1. It has dropped from a perfect 455 psi to around 400 (415 or so if I squirt some oil in the chamber). It seems like that would still be enough, especially because the repair limit in the service manual is 370 psi, but it still misfires and blows white smoke.
Heres where it gets strange. Testing cylinder 1 I get a perfect of 455 psi. Good. Cylinder 2, 700 PSI!. Thats 245 pounds over spec. And number 3 still has zero. I can't figure out for the life of me what is going on. Im scared to keep testing it with such high compression in that cylinder.
There were a few odd things I noticed when I had it apart too. First, the number 3 rings looked fine. Very little wear and certainly nothing that looked like it would cause zero compression. The top ring on the #2 piston, in fact, was broken. Second, the number 1 rod bearing was completely gone. I had to have the crank journal refinished and use undersize bearings because the scoring was so bad. I collected the shredded bearing from the oil pan. The others were fine.
Does anyone have any idea what might be going on here? I'd greatly appreciate any input.
*Edit- Also, the number two bearing had spun.
UPDATE: The zero compression on number 3 was a result of bad valve adjustments that got messed up when I pulled the rockers. Compression on cylinders 2 and 3 are now around 600 pounds. Still high, but they both run. It now seems that i am back to my original problem, but now it has moved over to cylinder 1. It has dropped from a perfect 455 psi to around 400 (415 or so if I squirt some oil in the chamber). It seems like that would still be enough, especially because the repair limit in the service manual is 370 psi, but it still misfires and blows white smoke.