"I have a possible low oil pre
"I have a possible low oil pressure problem which occurs only after running for about 4 hours. The symptoms started last summer; here's a list of what I know and what I've tried:
What I know:
1. This boat is a 2001 model which sits on a trailer in my garage most of the time. It has just 210 hrs on it in 7.5 seasons, so it doesn't see heavy use. It has a GM Vortec 4.3L V-6.
2. The low pressure warning starts when at idle and only after running pretty much stop and go pulling water skiers, wake boarders and tubes for ~3-4 hrs. It starts off reading low only at idle (and will increase to normal when rev'd >2000 RPM), but will drop to 0 and really jump around anywhere between 0-45psi when below 1200 RPM (according to the gauge, light and alarm on the dash.) Eventually, it will read a consistent 0psi regardless of engine speed.
3. The first time this happened I was miles from a marina. I had no choice but to run it in this condition - with the dash lighting up and alarm sounding - for 15 minutes at ~2,500-3,000 RPM to get back to the marina, so I doubt I could have run that long with 0 oil pressure.
4. The motor has 2 oil pressure senders; one sets an alarm when the pressure drops below 6psi (this one is in the engine compartment, and does an auditory self-test at every start-up, so I know it works; this one has never sounded) the second one runs the gauge on the dash - this is the one that is sounding an alarm, and lighting up the dash.
5. Coolant temps are typically at the low end of the "normal" range on the dash. No temps are given on the gauge, so I don't really know what "normal" is. The impeller is and always has been in good working order. There are no leaks from the engine water pump, so I have no reason to suspect low coolant flow.
6. It always seems to happen when the air temperature is >100F. Of course, those are the only days when I'm pulling skiers or boarders for >4h, too!
7. It gets annual oil and filter changes with synthetic 30wt oil.
What I have tried:
1. Oil change, using only Volvo Penta filter and 30wt oil. No change.
2. Replacing the sending unit that connects to the dash. No change.
3. Increasing oil change frequency to twice per year. That puts <30 hrs on the motor between changes, and the oil is barely dark when I change.
I was going to try a heavier, possibly multi-weight synthetic oil like a 20w50, but the owners manual specifically does NOT recommend a multi-weight oil, and 30wt is the heaviest they list.
Any thoughts before I take this to a professional?}"
"I have a possible low oil pressure problem which occurs only after running for about 4 hours. The symptoms started last summer; here's a list of what I know and what I've tried:
What I know:
1. This boat is a 2001 model which sits on a trailer in my garage most of the time. It has just 210 hrs on it in 7.5 seasons, so it doesn't see heavy use. It has a GM Vortec 4.3L V-6.
2. The low pressure warning starts when at idle and only after running pretty much stop and go pulling water skiers, wake boarders and tubes for ~3-4 hrs. It starts off reading low only at idle (and will increase to normal when rev'd >2000 RPM), but will drop to 0 and really jump around anywhere between 0-45psi when below 1200 RPM (according to the gauge, light and alarm on the dash.) Eventually, it will read a consistent 0psi regardless of engine speed.
3. The first time this happened I was miles from a marina. I had no choice but to run it in this condition - with the dash lighting up and alarm sounding - for 15 minutes at ~2,500-3,000 RPM to get back to the marina, so I doubt I could have run that long with 0 oil pressure.
4. The motor has 2 oil pressure senders; one sets an alarm when the pressure drops below 6psi (this one is in the engine compartment, and does an auditory self-test at every start-up, so I know it works; this one has never sounded) the second one runs the gauge on the dash - this is the one that is sounding an alarm, and lighting up the dash.
5. Coolant temps are typically at the low end of the "normal" range on the dash. No temps are given on the gauge, so I don't really know what "normal" is. The impeller is and always has been in good working order. There are no leaks from the engine water pump, so I have no reason to suspect low coolant flow.
6. It always seems to happen when the air temperature is >100F. Of course, those are the only days when I'm pulling skiers or boarders for >4h, too!
7. It gets annual oil and filter changes with synthetic 30wt oil.
What I have tried:
1. Oil change, using only Volvo Penta filter and 30wt oil. No change.
2. Replacing the sending unit that connects to the dash. No change.
3. Increasing oil change frequency to twice per year. That puts <30 hrs on the motor between changes, and the oil is barely dark when I change.
I was going to try a heavier, possibly multi-weight synthetic oil like a 20w50, but the owners manual specifically does NOT recommend a multi-weight oil, and 30wt is the heaviest they list.
Any thoughts before I take this to a professional?}"
