I have a 1971 40 with original engine, etc. The engine was rebuild a couple years ago by the PO.
The engine has developed a loud, metal on metal, rattle that started a few weeks ago. I thought it was the exhaust hitting the skid plate, but it isn't. The sound is like a heavy shroud loose. I had the air cleaner come loose once and it sounds like that. The sound appears to come from the front of the engine. I have been all over the front, top and bottom. I removed the fan pully, no change. I removed the air cleaner assy, no change. Checked the valves, nothing. Nothing is loose that I can find. The sound is loudest when you put your ear against the air cleaner. I had my neighbor double check me on everything.
The sound goes away a little above idle.
It doesn't sound like a rod or main cap to me, but I can't be certain. I have not heard a bad rod for a couple decades. Still, it could be something inside the motor.
Can I have suggestions? I can drain and pull the pan I guess, but not for a couple weeks. I am replacing the tranny in my wife's car and it has to come first.
Thanks for any advice.
Steve
The engine has developed a loud, metal on metal, rattle that started a few weeks ago. I thought it was the exhaust hitting the skid plate, but it isn't. The sound is like a heavy shroud loose. I had the air cleaner come loose once and it sounds like that. The sound appears to come from the front of the engine. I have been all over the front, top and bottom. I removed the fan pully, no change. I removed the air cleaner assy, no change. Checked the valves, nothing. Nothing is loose that I can find. The sound is loudest when you put your ear against the air cleaner. I had my neighbor double check me on everything.
The sound goes away a little above idle.
It doesn't sound like a rod or main cap to me, but I can't be certain. I have not heard a bad rod for a couple decades. Still, it could be something inside the motor.
Can I have suggestions? I can drain and pull the pan I guess, but not for a couple weeks. I am replacing the tranny in my wife's car and it has to come first.
Thanks for any advice.
Steve