Walshie831
Cadet
- Joined
- May 22, 2010
- Messages
- 7
Trying to get some other views on my problem here
Motor- 89 Merc 7.4 330hp w/ 279 hours
Had the boat out a few times this year and the last 2 days I've had this problem.
Starts up w/ 35-40psi @ idle. Runs great, get up to 2500rpm goes to 45psi.
Once it gets into operating range it is at about 25-30psi. I have about a 25 minute ride out to when I'm no longer in the no wake zone and I can get into it. About 10-15 minutes of 3200+ RPM's I notice that this engine just slowly starts to lose oil pressure. Over a course of about 20 seconds it drops right to zero. Obviously I shut it down let it cool off etc. Start it back up and PSI is right back to 20+ at idle.
Check the bilge no oil from either motor is in the bilge. No leaks, no water in the oil. Oil level is exactly where it was before the run.
Was hoping it was a bad sender, replaced it. Next day Same run as the day before same thing happens right about at the same time.
I'm off to buy a mechanical gauge hoping that somewhere there is a short to the gauge. There is no ticking, no knocking, motor doesn't heat up.
Any ideas? This boat is nowhere near as fun on 1 motor as it is on 2. Sorry for the long post just wanted to get all the info out I had.
Motor- 89 Merc 7.4 330hp w/ 279 hours
Had the boat out a few times this year and the last 2 days I've had this problem.
Starts up w/ 35-40psi @ idle. Runs great, get up to 2500rpm goes to 45psi.
Once it gets into operating range it is at about 25-30psi. I have about a 25 minute ride out to when I'm no longer in the no wake zone and I can get into it. About 10-15 minutes of 3200+ RPM's I notice that this engine just slowly starts to lose oil pressure. Over a course of about 20 seconds it drops right to zero. Obviously I shut it down let it cool off etc. Start it back up and PSI is right back to 20+ at idle.
Check the bilge no oil from either motor is in the bilge. No leaks, no water in the oil. Oil level is exactly where it was before the run.
Was hoping it was a bad sender, replaced it. Next day Same run as the day before same thing happens right about at the same time.
I'm off to buy a mechanical gauge hoping that somewhere there is a short to the gauge. There is no ticking, no knocking, motor doesn't heat up.
Any ideas? This boat is nowhere near as fun on 1 motor as it is on 2. Sorry for the long post just wanted to get all the info out I had.