Can anyone provide a "typical" range for operating temp. and oil pressure for a BZ482? I have a BZ482 with approximately 70 hours on it in a Cal 25 that I purchased last year. I ran the engine without issue last season and throughout the winter. I changed the recommended fluids at the start of this season (oil, oil filter, tranny fluid) and got a low oil pressure alarm and an overheat alarm on the first outing. I've noticed that after motoring for several hours the oil pressure drops to almost "0" when I throttle back to idle. A check of the dipstick revealed that I had slightly over-filled on the oil change, but not significantly. I've pumped off the excess, but the pressure still responds the same. Is it normal for the pressure to drop so low at idle? What is a normal pressure for motoring at approximately 2800-3000 rpm?
I still have to troubleshoot the overheat issue. Coolant level and raw water flow seem acceptable, but I overheat at anything over about 2600 rpm. From 2000 to 2600 rpm I run at about 90 to 95 degrees. Where should my temp be at cruise?
Obviously I should have paid closer attention to the gauges last season, but the fluid levels were all good and the engine ran great, so I focused on having fun instead. Hindsight...
Can you please let me know where you use the boat and what oil (type and grade) you are using.
The actual factory specs for the oil pressure is 14 PSI at idle (about 900 RPM)and 28 to 64 PSI at rated speed. The type of oil that you are using can affect this as well as the ambient temperature.
The normal running temperature on these engines is between 185 to 190 degrees F (85 to 90C).
I suspect that your overheat issue is the cause of the oil pressure issue so here is what I recommend. 1) remove the cover on the aft end of the heat exchanger (this is the one with the zinc on newer engines) and inspect for blockage of any of the tubes of the heat exchanger (see page 12 of the owners manual) 2) check that all the blades are intact on your raw water pump impeller. Please remove the impeller to do this. Usually if there are no cracks in the blades, the impeller can be re-used. Be careful when re-installing it so as not the damage it. I recommend using some vaseline to lubricate the impeller before refitting). 3) make sure that you idle speed is correct.
Please let me know how you get on. Regards, Stanley
Thanks for the quick reply and the suggestions. I keep the boat in Minnesott Beach and use it primarily on the Neuse and surrounding waters. I used Shell Rotella-T SAE 15W-40 in the most recent oil change. Based on the documentation I received when I purchased the boat, I believe that's what the previous owner ran as well. It's probably worth mentioning that I used a different oil filter than what was previously installed. The new filter is a Fram. I don't have the filter model in front of me, but it cross referenced as equivalent to the Wix model 51365 listed on the Beta parts list.
Thanks for the suggestions on the overheat issue. I plan to get to the boat this weekend so I'll try what you suggest and update you next week.
