View Full Version : MCX High Oil Pressure

07-29-2012, 10:23 PM
I have an '03 X-10 with MCX and about 640 hours. After the engine is warm (160 temp) at idle, the oil pressure gauge reads 40 psi. At 1000 rpm, 50 psi; 1500, 60 psi; 2000 70-80 psi; 2500 pegged 80+ psi. Today when my wife was pulling me for a ski, the alarm buzzer went off. She stopped immediately. Check engine light was not on. Checked dipstick, and near the bottom of operating range, but still okay.

After searching and reading other threads, I'm assuming bad sender, but I couldn't find an identical situation. Oil changed every year at winterization (approx 20 hours ago). Any suggestions of what to try?

07-30-2012, 12:26 PM
I'd try a new sender. Never seen a 350 with too high of oil pressure.
My LT-1 in my 190 used to run at 80psi on the guage all the time, MCX now shows lower on the guage.

07-30-2012, 10:24 PM
Talked with a service person at the Mastercraft dealer, and he indicated the readings I gave were normal. That just doesn't seem right that a needle would peg on a gauge and it be considered normal. Anyone have Oil Pressure readings for their MCX they'd like to share?

07-30-2012, 11:33 PM
I think mine shows 80 on the first whole shot for a few hundred meters than settles in around 60 or so. Never notice it pegging after that very first time. I usually let the boat idle up to temp before I take off.

08-03-2012, 10:39 PM
I let the motor warm up to close to 160 before I get on it. If I don't, I get an audio alarm - a solid beep, almost like a whistle - and I have to shut the motor off to get the alarm to shut off. All the other gauges look normal, except the oil pressure which pegs, and no check engine light at all. Tonight I was pulling my wife and the alarm went off. The boat was fully warmed up (approx 15 minutes) and this is the first time that's happened. Any idea of the high pressure would trigger the audio alarm without a check engine?

08-04-2012, 07:11 AM
As long as your oil filter doesn't burst you should be okay. What type of fluid are you running 20w 50?

08-05-2012, 12:23 AM
What type of fluid are you running 20w 50? Using what the dealer recommends, Rotella 15W40.

08-05-2012, 09:33 AM
thats a good weight to run, nevermind then

08-05-2012, 01:57 PM
Mine runs at 60 . Oil seems to be the right wieght, for the price of a sender I would just change it out and see what happens

08-29-2012, 03:43 PM
did you ever figure out the problem or did it correct itself? I have a 03 197 with the lq9 and for the last month i have had the same problem. since when i back to idle or pull at a slower rpm it goes down it figure i can make it till the end of the season here in wisconsin and will fix as i winterize it.