Mercruiser "double beep", what does it mean?

[ari]

Mercruiser \"double beep\", what does it mean?

Boat fitted with Mercruiser 4.3MPI sterndrive engine. It has a warning alarm and when you switch the ignition on it beeps once to let you know it's active and working. The idea of the alarm is that if you get low oil pressure, battery voltage or high water temp it sounds to alert you. (It also has "Smartcraft" which is electronic engine management which shuts the power down to an acceptable amount if it detects a problem).

Last night when out on the boat I started it up fine, headed out the harbour, and about every two minutes it gave a double beep (each beep about 1/2 second). Gauges were reading fine, exactly where they should be. Once we were out I opened her up (I thought it could possible be low battery and maybe more revs would give it more alternator) and watched the guages. Still perfect, boat performing fine, still the double beep every two mins or so.

Stopped at destination (only 10 min run), dropped anchor, shut off engine.

Re started about an hour later. Tried blipping the engine in neutral just to see what happened. Every time the engine peaked (about 3,000prm or so) it would bleep once and stop as the revs dropped.

Set off gently, built up speed, no bleeps, not even the double bleep we had initially on way out. Eased revs up and up, absolutely fine, gauges all fine, no problems. Wound it out to WOT briefly, still perfect.

Back into harbour, no bleeps, no double bleeps, nothing.

Totally mystified by it. It's never bleeped once (apart from ignition on test bleep) in three years of use.

Will check manual (didn't have time last night) but it's on the boat so can't check it till next down there.

Tried to find an online manual to download to see if it said anything but no joy.

Any thoughts or ideas most welcome.

 

[ari]

Re: Mercruiser \"double beep\", what does it mean?

Just spoke to the Mercruiser agent (should have tried that first really shouldn't I?) and he says it's warning of a fault code registered within the electronics and they'll need to plug their diagnostic computer in to see what's what. Doesn't sound too onerous from what he was saying as it's not limiting the revs as it will do if it's anything at all serious.

Also said it's worth checking the outdrive oil level as of course there's no gauge for this one so if it is a tad low I'll only tell by checking the sight reservoir.

 

[Nautorius]

Re: Mercruiser \"double beep\", what does it mean?

Hi,

Check your Gear Oil reservoir. If it is low it will bleep like mad! Normally top right of engine.

Cheers

Paul /forums/images/graemlins/smile.gif

 

[[2068]]

Re: Mercruiser \"double beep\", what does it mean?

Disclaimer: I'm not a mechanic, and don't really know the answer, but I found this on another forum that might be relevant.

Looks like it could be a variety of things, but you need to plug it in to a code reader (at the dealer) to find out which it is.
Full discussion HERE.

###

These engines would have the ECM555 system and the code tool trick won't work. A two beep per minute alarm is called a "soft" alarm and usually will cut back Available Power to 90%. When the alarm goes steady, that's a "hard" alarm and the Available Power can be reduced to as low as 0% (engine stalls).

###

dv.

 

[lovezoo]

Re: Mercruiser \"double beep\", what does it mean?

FYI on my 4.3EFI I regularly check the drive lube reservoir and have had to refill this twice this season. The Mercruiser mechanic that services the engine seemed to think that this was ok. The oil appears to be leaking (very slightly) from the drain plug on the bottom of the leg.

 

[itsonlymoney]

Re: Mercruiser \"double beep\", what does it mean?

Agree with Paul, check lubricant levels in all reservoirs. I beleive some or all of em can give this audible tone.

 

[alan006]

Re: Mercruiser \"double beep\", what does it mean?

Yes, I've heard these engines do this when the oil level drops on the drive reservoir.

 

[ari]

Re: Mercruiser \"double beep\", what does it mean?

Thanks all. /forums/images/graemlins/smile.gif

Checked the drive reservoir and it was indeed on the "top up" mark so did that.

Still got the double beep a couple of times when going out but other than that all fine. Boat performing perfectly, pulling correct revs etc so don't think there's much wrong.

Mercruiser dealer going to plug their diagnostic computer in and check/reset fault codes but said not to worry about it, prob minor otherwise it'd have been making more fuss, restricting revs etc so all good I think.

Thanks again for the responses though, most useful.

 

[Stupot]

Hi I'm having a problem with my 5litre MPI guardians system. I am getting a double beep every 4-5mins. This continues all the way up to 4000 rev's. After that it goes to a continuous tone and warns me to go to low rev's. All the readings on the clock are okay, water temp 170, oil pressure 45, water pressure 12 bar. I have changed all of the sensors that monitor the water temperature as I thought they may be giving a false reading, saying the engine is over heating. I have also installed a new impeller. I've checked all oil levels and they're fine, just the engine has slightly too much in. Any ideas would be gratefully appreciated.

 

[Mr Googler]

Have you had the codes read as you could be changing things for no reason?

 

[julians]

Hi I'm having a problem with my 5litre MPI guardians system. I am getting a double beep every 4-5mins. This continues all the way up to 4000 rev's. After that it goes to a continuous tone and warns me to go to low rev's. All the readings on the clock are okay, water temp 170, oil pressure 45, water pressure 12 bar. I have changed all of the sensors that monitor the water temperature as I thought they may be giving a false reading, saying the engine is over heating. I have also installed a new impeller. I've checked all oil levels and they're fine, just the engine has slightly too much in. Any ideas would be gratefully appreciated.

plugging in a fault code reader will tell you for sure, but my money is on a faulty idle air control valve (IACV). I had the same problem on my 5.0mpi. Its located on top of the engine underneath the air filter, it has two air pipes going into it, one comes from just under the air filter the other goes to the other side of the throttle butterfly, and an electrical connector. If this is at fault, if you unplug it, your engine will struggle to idle correctly, but the beeping should stop. Whilst I waited for a new valve to arrive from the US, I unplugged mine, and tweaked the throttle cable to allow the engine to idle correctly.

These were known to be problematic, I went through 2 in the 7 years I owned a boat with a 5.0 mpi.

 

[Stupot]

Thanks for this I'll try this over the weekend and let you know how things go

 

[B58]

Two beep per minute is a small fault most commonly associated with the block pressure sensor located on your power steering cooler. Reading the diagnostic info of the ECU will show this failure as well as a 10% power drop. Go to a Mercruiser dealer they will use thier dianostic tool (CDS) and resolve your problem.


The other members comments were refering to gear oil resovoir, which has a continuous alarm (same as low oil pressure, or overheating) and power reduction will depend on the engine status usualy 50% so quite noticable.

Idle air control valve won't necessary cause a fault, the motor is bullet proof but the slide can stick over time and your engine will idle like a pig or not idle at all but a fault wont be shown unless the motor burns out.