Mercruiser 4.3 2005 inboard with Bravo II leg (Twin)

pierreinsa

Recruit
Joined
Sep 3, 2013
Messages
3
Hi,

I have twin Mercruisers in my 2005 Riviera M290 (Recent acquisition). Only 200 hours on the clocks.
My starboard engine turns on, emits the self test beep, and then I am able to start first time. All normal so far.

The engine will idle perfectly, oils and temp gauges are normal. One I get into mid stream, and throttle up to about 1500 rpm, the starboard engine warning buzzer emits a constant sound. Also, I loose revs and when returning to idle, the beep stops. This is only from the starboard engine, the port is engine does not miss a beat.
I have checked the leg oil level. I do not appear to have blockages in the sea water reservoir as I have removed both end cap plates to inspect, thinking there may have been seaweed ingested into the cooling system.

I don't have access to a diagnostic tool but i am sure I have a faulty sensor somewhere, but trying to determine which it may be is quite difficult.

Any suggestions gratefully received.

Regards,

Peter
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
8,776
Re: Mercruiser 4.3 2005 inboard with Bravo II leg (Twin)

Hi there Peter, sounds like your engine is an MPI? Do you by chance have the engine serial number handy to start off with?

Also, is your cooling system a closed cooling system with antifreeze running through it? Thanks.:)
 

pierreinsa

Recruit
Joined
Sep 3, 2013
Messages
3
Re: Mercruiser 4.3 2005 inboard with Bravo II leg (Twin)

Hi there Peter, sounds like your engine is an MPI? Do you by chance have the engine serial number handy to start off with?

Also, is your cooling system a closed cooling system with antifreeze running through it? Thanks.:)

Hi,

Just thought I would share the cause of the Engine Warning at anything over 1500rpm. It appears as though the Water Pressure Switch was stuck. I replaced the offending device and the warning no longer occurs...
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
Re: Mercruiser 4.3 2005 inboard with Bravo II leg (Twin)

:welcome: to iboats

The water pressure switch is the number one cause for the beeps
 

pierreinsa

Recruit
Joined
Sep 3, 2013
Messages
3
Re: Mercruiser 4.3 2005 inboard with Bravo II leg (Twin)

:welcome: to iboats

The water pressure switch is the number one cause for the beeps

Ok. Thanks for the feedback. I will remember that...I replaced both (one in each engine) and keep the working one as a spare as its a small part.
Does anyone have any other more common type faults that are easily fixed like this?
 

MarkSee

Lieutenant Junior Grade
Joined
Sep 10, 2010
Messages
1,172
Re: Mercruiser 4.3 2005 inboard with Bravo II leg (Twin)

When I had my Maxum which also was a 2005 4.3 mpi, I started getting the beep every 2 minutes at any rpm and ended buyiing the scan tool which showed I had a low water pressure code. I replaced the water pressure sensor unit that screws in to the top of the power steering cooler at the top behind the engine; #17 in this link:
Power Steering Components-Performance Product Technologies
I'm assuming this is different than the "switch" you replaced.

Mark
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
Re: Mercruiser 4.3 2005 inboard with Bravo II leg (Twin)

Got this from one of FunTimes post, should help with future problems

Warning system Faults, SC1000 Yes/No, Audio Alarm, Available Power %, Description.

(1) Cam Sensor Yes 2 Bp/min 90% Open or short, engine must be cranking to set this fault code.
(2) ECT CKT HI Yes 2 Bp/min 90% Open
(3) ECT CKT LO Yes 2 Bp/min 90% Short
(4) ECT Coolant Overheat Yes Constant 6-100 % Engine guardian overheat condition
(5) EST 1-8 Open Yes 2 Bp/min NA Coil harness wire open
(6) EST 1-8 Short Yes 2 Bp/min NA Coil harness wire short
(7) Fuel Injector 1-8 Open Yes 2 Bp/min NA Fuel injector wire open.
(8) Fuel Injector 1-8 Short Yes 2 Bp/min NA Fuel injector wire short
(9) IAC Output Yes 2 Bp/min 90% Only with rpm
(10) Knock Sensor 1 Yes 2 Bp/min 90% Alarm sounds for 20 seconds in NEUTRAL and indefinitely in gear.
(11) Knock Sensor 2 Yes 2 Bp/min 90% Alarm sounds for 20 seconds in NEUTRAL and indefinitely in gear.
(12) Low Drive Lube Strategy Yes Steady Bp 0-100% Low oil in sterndrive.
(13) Low Oil Pressure Strategy Yes Constant 0-100% Low oil pressure strategy.
(14) MAP Sensor 1 Input High No 2 Bp/min 90% Short, no visual on SC1000.
(15) MAP Sensor 1 Input Low No 2 Bp/min 90% Open, no visual on SC1000.
(16) MAT Sensor Yes 2 Bp/min 90% Open or short in MAT circuit.
(17) Oil PSI CKT Hi Yes 2 Bp/min 90% Short, defaults to 51.7 psi.
(18) Oil PSI CKT Lo Yes 2 Bp/min 90% Open, zero oil pressure.
(19) Overspeed Yes Constant RPM Limit Engine over rpm limit
(20) Port EMCT CKT Hi Yes 2 Bp/min 90% Open, defaults to 32 degrees F.
(21) Port EMCT CKT Lo Yes 2 Bp/min 90% Short, defaults to 32 degrees F.
(22) Port EMCT CKT Overheat Yes Constant 6-100% Overheat condition, 212
degreesF(100 degrees C) limit.
(23) Sea Pump PSI Lo Yes Constant 6-100% Low water pressure strategy, defaults to 43.4 psi.
(24) Sea Pump CKT Hi Yes 2 Bp/min 90% Open.
(25)Sea Pump CKT Lo Yes 2 Bp/min 90% Short.
(26) STB EMCT CKT Hi Yes 2 Bp/min 90% Open, defaults to 32 degrees F.
(27) STB EMCT CKT Lo Yes 2 Bp/min 90% Short, defaults to 32 degrees F.
(28) STB EMCT CKT Overheat Yes Constant 6-100% Overheat condition, 212 degrees (100 degrees C) limit.
(29) Steer CKT Hi Yes No No Open and short.
(30) TPS1 CKT Hi Yes 2 Bp/min 90% Short, signal to 5v+, engine will not start. Refer to data monitor screen.
(31) TPS1 CKT Lo Yes 2 Bp/min 90% Open.
(32) TPS 1 Range Hi Yes 2 Bp/min 90% Above 4.8v, 994 counts.
(33) TPS 1 Range Lo Yes 2 Bp/min 90% Below 0.5v, 35 counts.
(34) Trim CKT Hi Yes No No Short, high range, visual warning on SC1000 only.
(35) Trim CKT Lo Yes No No Open, low range, visual warning on SC1000 only.
(36) 5 VDC PWR Low Yes 2 Bp/min varies Short any 5v+ to ground.


Here's some other information that what will sound the alarm on a mercruiser Engine.
Constant tone alarms are for:
1.) engine coolant temp overheat,
2.) low engine oil pressure,
3.) engine overspeed,
4.) exhaust manifold cooling temp overheat
5.) sea pump PSI low.
Note #5 is known to be a common problem, It's been said that this fault might not show up in the fault history section of the scan tool.
If that is the case then the only other way to know if this is your problem, is to watch this sensor live as it happens out on the water with the scan tool hooked up to the engine.
Also make sure all the Battery cables are clean & tight plus a fully charged Battery is very important.
Check the water pressure sensor threads for any paint, Also check the sensor to see if it has come loose or Has a blockage of some kind.
If any sensor loses it's ground it could sound the alarm. As an additional test, try adding a ground wire to the sensor threads to stop the horn.
Or there is a chance you could have picked up or created some air bubble for a short time, until the boat slowed down, possibly due to the brass water pump impeller Housing could be failing do to deep grooves inside housing creating a disturbance with the water flow.

Constant beep alarms are for:
1.) low outdrive lube level.

Two Alarm beeps every 60 seconds are for:
1.) Faulty cam,
2.) IAC,
3.) MAP,
4.) MAT,
5.) knock sensors.
6.) open/short in the engine cooling temp circuit
7.) open/short in fuel injector wiring circuit,
8.) open/short in oil PSI circuit,
9.) open/short in exhaust manifold cooling temp circuit,
10.) open/short in sea pump circuit,
11.) open/short in throttle position circuit
 
Top