the_workmaster
Member
Hey everybody. I've been tuning in my 134ci gas engine, from a 640, now in a 641 formerly diesel. The gas engine seems to have been very freshly rebuilt, but sat for years outdoors after that rebuild, maybe as much as 10-20 years.. heavily rusted on the outside. Clean as a dinner plate inside though, almost no carbon in the exhaust ports, bare metal intake ports, just a few specs of oil gunk on the valve stems. Mice had filled the ports with acorns, but they never got wet, no visible rust whatsoever.
After a day or two of starts/runs, I started to have 1-2 dead cylinders for as much as a couple minutes at startup. They always either come online themselves, or respond to a throttle increase and then stay on, but I've heard some clangs and dings from the engine at the moment they come online. I've interpreted that as sticking valves, the clang coming when they free up (hopefully not when they're hit by pistons.......). Then, sometimes on throttle up or throttle down, going through the middle of the rpm range, around 1000, there's occasionally a rapid metal rapping noise for a few seconds. Oil pressure is always above 40, often closer to 60.
What does this all mean, and what can/should I do about it?
Thanks, Alex
After a day or two of starts/runs, I started to have 1-2 dead cylinders for as much as a couple minutes at startup. They always either come online themselves, or respond to a throttle increase and then stay on, but I've heard some clangs and dings from the engine at the moment they come online. I've interpreted that as sticking valves, the clang coming when they free up (hopefully not when they're hit by pistons.......). Then, sometimes on throttle up or throttle down, going through the middle of the rpm range, around 1000, there's occasionally a rapid metal rapping noise for a few seconds. Oil pressure is always above 40, often closer to 60.
What does this all mean, and what can/should I do about it?
Thanks, Alex