Alarm When Engine not Running / Stops After Disconnecting Oil Sensor

graves_7

Cadet
Joined
Sep 29, 2016
Messages
12
I have a 2001 Larson 190 with a Volvo 4.3L PEFS engine. When I was at the lake last weekend, the boat would not get above 2500 RPMs and after investigating I noticed that one of the exhaust hoses was leaking. I also noticed that when I turned the key to the on position a steady beeping alarm occurred; however, the alarm stops when the engine is running. I replaced the leaking exhaust hose this week, but the audible alarm is still happening when I turn the key to the on position (still goes off as soon as the engine starts). I determined that the alarm stops when I disconnect the Oil Pressure Sensor near the Oil Filter, so I replaced this sensor today, but the alarm is still doing the same thing. I haven't been back to the lake yet to see if the boat will get above 2500 RPM's after replacing the exhaust hose. Anybody have an idea what else I can do to troubleshoot the alarm issue?
 

Fishhead-1

Petty Officer 2nd Class
Joined
Oct 10, 2003
Messages
110
the alarm is on with key on because of lack of oil pressure that's why it goes off when it starts running. Sounds like it's in limp mode but no alarm when it was running is that right?water temp ok?
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
Is this a fuel injected engine? You left out some of the letters before "PEFS" in your model number.
 

graves_7

Cadet
Joined
Sep 29, 2016
Messages
12
the alarm is on with key on because of lack of oil pressure that's why it goes off when it starts running. Sounds like it's in limp mode but no alarm when it was running is that right?water temp ok?

That's correct. It was in limp mode when the engine was running but no alarm. Could the leaking exhaust hose cause it to go into limp mode? Temp seemed ok according to the gauge. It used to beep a couple times when i turned the key to the on position then go off...now it will stay on forever.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
Sender and a switch for oil pressure and a sender and a switch for water temp. Disconnect both of the switches to see if it now goes out of limp mode. Just keep in mind that the switches have nothing to do with the gauges. if your gauges for oil pressure and water temp stop working after you disconnect the wires, you disconnected the wrong thing.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
My guess is this is either a new to you boat, or the oil pressure switch and or alarm has started to work. The alarm should sound off when the motor is OFF and the key is ON. The only reason the alarm would not sound with the key ON, is there is a capacitor in line which will give it about 15 to 20 seconds before it sounds off. This is normal and forget about that issue, its not a problem.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
I looked at the manual for your model. Doesn't look like your engine has a limp mode, only an alarm. Your 2500 RPM issue is not related to your alarm.
 

graves_7

Cadet
Joined
Sep 29, 2016
Messages
12
Thanks for all of the feedback!

AllDodge you are correct I have only had the boat a couple of months, so the alarm must have start working. I'll scratch that off my list of issues.

​@bruceb58 I just went back and looked at my manual and you are also correct...I read that there is a limp mode in the manual but it was for the Fuel Injected model.

​I was actually able to take the boat out to the lake today. I wanted to see how it acted after replacing the leaky exhaust hose and I also changed the fuel filter. What I thought was limp mode is obviously some other issue. The boat didn't have the power it usually has...I can usually reach about 43 MPH with the wife and I on board, but my max speed today was 35 MPH with just me onboard. I also noticed when I would go from idle to full throttle the boat would hesitate before taking off. I guess I should probably go through the "List of possible causes of low WOT" in the DIYer sticky.
 
Top