xbones2000
New member
"Hi everyone,
I've got
"Hi everyone,
I've got a Volvo Penta MD7A in my sailboat. When I bought her three years ago the engine had some problems with hot cycling, where it would go from cool to very hot every 2 minutes. I replaced the thermostat and had a radiator shop blow out the cooling manifold, which was completely full of gunk.
It ran fine for a month, then the current problem started. The engine starts like a champ and runs fine for 15-30 minutes. RPMs at max are 2300. Then the max RPM's slowly creep down. 10 minutes later I can't get more than 1800...in 5 minutes it's 1500, and so on. The bottom end drops out too, and bringing it down to idle will stall it out.
Here's what else is going on:
- Temperature is reading cool the whole time.
- The diesel fuel is two years old, but is crystal clear red and gunk-free.
- A new racor filter shows no signs of water.
- If the engine is turned off for 5-10 minutes, the problem resets itself. I.e., back to 2300 max RPMs.
- Water flow from the back seems a little low.
- The problem doesn't happen in the slip, even under load.
- It's not a clogged air vent (still happens with the fuel cap open).
- I don't think it's a air leak in a line, because it wouldn't run well in the beginning so consistently.
- I don't think it's a fuel clog for the same reason, and it likely wouldn't die so slowly.
- The fuel shutoff cable isn't easing itself out from vibration.
The problem got suddenly worse last week, and now the max RPM's are only 1300!
My mechanic and I are running out of options, and he's now telling me his next step requires a young priest and an old priest. Any help you could provide would be great!
Thanks in advance,
Dave"
I've got
"Hi everyone,
I've got a Volvo Penta MD7A in my sailboat. When I bought her three years ago the engine had some problems with hot cycling, where it would go from cool to very hot every 2 minutes. I replaced the thermostat and had a radiator shop blow out the cooling manifold, which was completely full of gunk.
It ran fine for a month, then the current problem started. The engine starts like a champ and runs fine for 15-30 minutes. RPMs at max are 2300. Then the max RPM's slowly creep down. 10 minutes later I can't get more than 1800...in 5 minutes it's 1500, and so on. The bottom end drops out too, and bringing it down to idle will stall it out.
Here's what else is going on:
- Temperature is reading cool the whole time.
- The diesel fuel is two years old, but is crystal clear red and gunk-free.
- A new racor filter shows no signs of water.
- If the engine is turned off for 5-10 minutes, the problem resets itself. I.e., back to 2300 max RPMs.
- Water flow from the back seems a little low.
- The problem doesn't happen in the slip, even under load.
- It's not a clogged air vent (still happens with the fuel cap open).
- I don't think it's a air leak in a line, because it wouldn't run well in the beginning so consistently.
- I don't think it's a fuel clog for the same reason, and it likely wouldn't die so slowly.
- The fuel shutoff cable isn't easing itself out from vibration.
The problem got suddenly worse last week, and now the max RPM's are only 1300!
My mechanic and I are running out of options, and he's now telling me his next step requires a young priest and an old priest. Any help you could provide would be great!
Thanks in advance,
Dave"