Monterey 263
Cadet
- Joined
- Jun 1, 2019
- Messages
- 10
To all you engine gurus - I need help! BLUF: Three motors in three months have eaten main and rod bearings and we can't figure out why.
Long story: Engine had to come out at the end of last season due to water in number 7 cyl. After pressure testing, the head was found to have corroded through to the exhaust port. Thus total rebuild of the motor while it was out. New wiesco pistons, main bearings, line bore, new rods and rod bearings, new heads and valves, all bolts, essentially everything but the block, crank, and cam were brand new. Back in the boat it went, and motor aligned to where the tool could spin with two fingers easily. New gimbal bearing and seal too. Motor started and ran fine for about an hour and slowly started to lose oil pressure and got sluggish. Cut the oil filter open, full of brass. Pulled it to find the main and rod bearings trashed. Cleaned it all up, new crank, new line bore, new rods, and a lot of cleaning. Motor lasted 4 hours and same result. Not wanting to put the cursed motor in again, I bought a marine long block from a local machine shop already assembled. Bolted on the manifolds, distributor, and remote oil filter and lines. Dropped it in the boat, ran for perfect for about 7 hours, then it started to lose oil pressure and got sluggish. Cut the filter open again, more metal. Pulled it and opened it up, spun two rods, and ate up the rest. Now these are two different motors with the same thing happening. The only commonality are the intake and exhaust manifolds, the distributor, the outside accessories, and the remote oil filter. Thinking there could be some de lamination in the remote oil filter lines causing a blockage, I cut them open, and they were perfect inside, so there was no oil flow restriction. All the local shops are shaking there head and have no idea why this could be happening. I grasping at straws, anyone have ideas for me? I don't want to drop another motor in without know why this keeps happening.
2005 Monterey 263, Volvo Penta 5.7GXi-F.
Long story: Engine had to come out at the end of last season due to water in number 7 cyl. After pressure testing, the head was found to have corroded through to the exhaust port. Thus total rebuild of the motor while it was out. New wiesco pistons, main bearings, line bore, new rods and rod bearings, new heads and valves, all bolts, essentially everything but the block, crank, and cam were brand new. Back in the boat it went, and motor aligned to where the tool could spin with two fingers easily. New gimbal bearing and seal too. Motor started and ran fine for about an hour and slowly started to lose oil pressure and got sluggish. Cut the oil filter open, full of brass. Pulled it to find the main and rod bearings trashed. Cleaned it all up, new crank, new line bore, new rods, and a lot of cleaning. Motor lasted 4 hours and same result. Not wanting to put the cursed motor in again, I bought a marine long block from a local machine shop already assembled. Bolted on the manifolds, distributor, and remote oil filter and lines. Dropped it in the boat, ran for perfect for about 7 hours, then it started to lose oil pressure and got sluggish. Cut the filter open again, more metal. Pulled it and opened it up, spun two rods, and ate up the rest. Now these are two different motors with the same thing happening. The only commonality are the intake and exhaust manifolds, the distributor, the outside accessories, and the remote oil filter. Thinking there could be some de lamination in the remote oil filter lines causing a blockage, I cut them open, and they were perfect inside, so there was no oil flow restriction. All the local shops are shaking there head and have no idea why this could be happening. I grasping at straws, anyone have ideas for me? I don't want to drop another motor in without know why this keeps happening.
2005 Monterey 263, Volvo Penta 5.7GXi-F.