robbm2k wrote:
so i recently switched boats to a 2005 Horizon 200LE and the engine ran OK first couple times without any notice of the gauges high or reading abnormal (considering the trim gauge wasn't working and I had to blow out the speedo line, i feel like i wasn't oblivious/ignoring the gauges). Out this weekend and the oil pressure was reading 40 PSI at idling and while trolling, and 60-70 PSI at 3/4 WOT and has me concerned (gauge range is 0-80). Manual says pressure minimums way below these values, but also, that's minimums, so i'm not sure how much higher than those i should be concerned about. i definitely didn't want to run it at WOT and peg the oil pressure gauge. temp gauge was fine the whole time. old owner said the oil had been changed when he had it winterized in the fall, and oil level on dipstick looks good. Suggestions on what else to check? Had a date scheduled to have it given a once-over and tune-up next week anyways, but would like to look into what I can and see if anything I can check if I take it out this weekend. Thanks in advance.
manual for the 5L GL:
Oil Pressure (Minimum)
@ 1000 RPM . . . . . . . . . . . . . . . . . . . . . . 6 PSI (41 kPa)
@ 2000 RPM . . . . . . . . . . . . . . . . . . . . . . 18 PSI (124 kPa)
@ 4000 RPM . . . . . . . . . . . . . . . . . . . . . . 24 PSI (166 kPa)
Well, those minimums would not make me happy at all! In practice your OP readings are not out of line depending on what oil is being used...if its a straight weight you can get those readings, as you can with the Merc 25/40. On my ancient '88 4.3 I get
40 psi at cold slow idle, running speeds 50-60 psi, sometimes a bit higher, not as high as 80 though. After coming off plane, it will usually drop to 30 or so. So, I don't really think you have a problem! If I had 6 psi at idle, or 24 psi at 4000 to me that's a problem!
https://www.dropbox.com/s/25070o8154ssw ... l.jpg?dl=0this was taken after idling for a while after coming off plane. 40 psi. Engine is 32 years old...