Sustained "Alarm" - Mercruiser 4.3LX

[Nauteal]

<br />I own a 1995 Mercruiser V6 4.3LX. When I stored the boat last year in my garage everything was fine. This year when I pulled it out - the first thing I notice is the blower is not functioning (switch tested fine.) I have not bench tested blower yet. On top of that when I put the flush ears on it to start it out of the water, the alarm you hear for a few seconds when the boat is first started is now sustained.<br /><br />If I am understanding what the Alarm is doing, it is warning me that the engine is not getting water? but the exhaust had water in it coming out the prop. Could this be a defective sensor? Or could there be some sort of impeller partially clogged allowing some water to be pumped, but not enough. Waterpump on the front of the engine is not leaking. Thoughts?

 

[jlshields]

Re: Sustained "Alarm" - Mercruiser 4.3LX

That alarm you're hearing also warns of low engine oil pressure and low outdrive lube level along with engine overheat. If it were engine overheat it wouldn't sound off right away on starting the engine. You did have oil pressure? I would guess low outdrive lube.

 

[Nauteal]

Re: Sustained "Alarm" - Mercruiser 4.3LX

You raise some very interesting points about what the alarm is indicating. I changed all fluids yesterday - engine oil, I used the Mercury 4/cycle oil. I feel there may be a red flag on the next one. I replaced the outdrive leg oil, going from a natural oil to a synthetic. I am wondering if the natural and the synthetic are incompatible, although I did do a full drain before adding the new oil. The new oil was pumped in from the bottom.

 

[rodbolt]

Re: Sustained "Alarm" - Mercruiser 4.3LX

hello<br /> what jlsheilds was saying is the alpha gen II of that year, most used an oil resevoir mounted on the motor to monitor drive lube. it must be cleaned and filled. if its low the float switch drops and alerts the operator that the engine has a problem. check the drive lube resevoir.<br /> good luck and keep posting

 

[Nauteal]

Re: Sustained "Alarm" - Mercruiser 4.3LX

I have found this reservoir on the top right side of the engine as I am facing the stern from inside the boat. My first 4.3LX did NOT have this. I have missed this and this again means I have mixed dissimilar oils. Is the float switch located inside this reservoir or down line somewhere? Once I understand all that is working here I am going to go back and flush the system and fill it back with all the same fluid. Thanks so much for all the help.

 

[Bayrider]

Re: Sustained "Alarm" - Mercruiser 4.3LX

Yes the float switch is inside the res .You will notice the wire going into the bottom of the res .One other thing to remember,I think that when you pump the oil to the vent you plug it.Then keep pumping onto you reach the res,then plug the drain.That should stop any air pockets froming in the drive. Regards Raymond.

 

[jlshields]

Re: Sustained "Alarm" - Mercruiser 4.3LX

Nauteal, first, if you used Quicksilver gear lube, the 'High Performance' and the 'Premium' do not mix. I would do like you said. Let it drain, maybe overnight, then refill like Bayrider says then watch the reservoir. When the drive warms up, not just on the muffs, it will 'burp' and work the air out of the cavity above the vent plug. You won't have to do anything but check the res. and add lube.

 

[Nauteal]

Re: Sustained "Alarm" - Mercruiser 4.3LX

This has been a big help! I will do a follow-up posting here after I have completed the procedure.

 

[sebago1]

Re: Sustained "Alarm" - Mercruiser 4.3LX

I have a 4.3 Gen 2 Alpha. The engine is a 2007 and to date I am on my third drive lube monitor. The sensor fails continously after a few months of boating. All fluids, Temps, pressure have been normal. I'm starting to think there is an engineering flaw in the system..