Audio warning drove me nuts yesterday?!?

Hello all,<br /><br />Newbie here so if something absolutely idiotic...you know. <br /><br />New to the I/O experience but fairly adept at reading the manual and making the right things progress. Anyhow, I have [by visual inspection only] a '00 Merc 5.7 Thunderbolt V w/2bbl carb. The serial number is VL12019MH. It has an Alpha Gen II outdrive. <br /><br />Since doing the summerization seen on the forums here I have had the boat out four times without any problems...save for not putting the plug in the first time, doh! <br /><br />I went out yesterday and the ignition audio warn came on as usual but would not turn off. After the usual 10 sec or so run, the sound became muffled but persisted. All the guages were in the normal ranges and when I lifted the hatch the engine was warm, definately not overheated. We have a large no-wake zone so I idled out of it, approx. 10 min. or so and the audio was still on. Engine and guages were still as above. <br /><br />I throttled her up and at about 3000 rpm the audio quit and didn't come back on...until I powered her off and started up again. From that point the audio stayed on and I was at least 30 minutes from the dock so, without any indication of overheating I disconnected the audio warning for the trip back in. <br /><br />Two questions: <br /><br />What is the audio warning warn for, i.e. overheat, prop in the water, no water flow, etc?<br /><br />As a side question, what is the HP rating of the MH designated Merc 5.7s? <br /><br />My Seloc manual for the Merc comes up short on this subject stating that there may be a problem with the brown/blue wire going to the engine but nothing else. <br /><br />Thanks a bunch for helping out and hope everyone's boating season is fun and safe.

Re: Audio warning drove me nuts yesterday?!?

Standar audio warning monitors three things: engine oil pressure, engine temp, and drive oil level. If your engine oil pressure and temp was okay, check the gear oil level in the drive---you may have a leak or if it was changed, may not have been filled to proper level.

Re: Audio warning drove me nuts yesterday?!?

Aha! I changed the gear oil on the drive before this trip. I filled it from the bottom up and stopped when the oil started coming out of the top vent hole. Is this correct or should I have put the vent screw back in and kept pumping? The drive took approx. 1.4 quarts total.

Re: Audio warning drove me nuts yesterday?!?

When the gear oil starts to come out the side vent, put the plugs back in. There is no need to fill anymore. There is a dipstick on the top which you can take off and check the level by looking at the line. I would say that it could be a faulty sending unit but you said all the guages are reading okay. Might want to check fuses, I know it sounds odd but ya never know.

Re: Audio warning drove me nuts yesterday?!?

Don't you also have a gear lube resevoir in the engine compartment?, that being low will also sound the alarm. Possibly when you powered up to 3000 the boat was on a different angle/attitude which caused the lube to move and shut off the alarm?

Re: Audio warning drove me nuts yesterday?!?

Check the gear lube resevoir in the engine compartment. I think the sensor that triggered the alarm is actually monitoring this and not the actual lube in the drive. You may have enough lube in the drive, but the resevoir is low.<br /> It may have drained out when you drained the lube from the drive and now it needs to be topped off.

Re: Audio warning drove me nuts yesterday?!?

Hey look at that - the Bobs agree.<br /><br />P.S. I think the Mercruiser 5.7L is a 260HP carburated, and 300HP if it's fuel injected, but I may be wrong.

Re: Audio warning drove me nuts yesterday?!?

Actually the rating for that vintage is done at the propshaft and is 250 bhp. 5.7Ls still are. The MPI is the 350 MAG and is rated at 300 bhp. The old carbed 260's were rated at the flywheel . . .

Re: Audio warning drove me nuts yesterday?!?

Originally posted by Bob Louderback:<br /> Check the gear lube resevoir in the engine compartment. I think the sensor that triggered the alarm is actually monitoring this and not the actual lube in the drive. You may have enough lube in the drive, but the resevoir is low.<br /> It may have drained out when you drained the lube from the drive and now it needs to be topped off.

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That would be my guess also. The reservoir is located to the port side of the carb towards the back of the engine. Give it a look.

Re: Audio warning drove me nuts yesterday?!?

I cannot imagine doing anything but shutting the engine off immediately after hearing the alarm and not starting it again until I knew precisely what was causing it. Increasing speed to see if it goes away is the last thing I'd do.<br /><br />That engine absolutely has a gear lube reservoir in the engine compartment and if you only filled to the vent hole, it is going to be low on lube. When filling, aftre lube comes out the vent hole, you need to put the vent plug back in and continue to fill until the reservoir is between the two limit lines. At this point, it probably would not hurt anything to just top it off in the engine compartment.

Re: Audio warning drove me nuts yesterday?!?

If the reservoir is truly empty, won't filling it from the engine compartment cause air to be trapped in the line? Will it work its way out?

Re: Audio warning drove me nuts yesterday?!?

JoJo---did you know you had a gear oil site check reservoir? If you did not pop the reservoir cap, during your gear oil change, you probably did not drain all the old oil.<br /><br />If the reservoir is completely empty, I would start over again with new gear oil pumped in from the bottom up. If the reservoir still has some oil in it, just fill to the line and alarm will stop.

Re: Audio warning drove me nuts yesterday?!?

Remerber my first statement..."idiotic"?<br /><br />Had no clue there was a resevoir for the gear oil. I'll have to check to see if there is fluid still in there but either way I may just start over. I had read some website instructions and must have missed the resevoir part.<br /><br />So, to clarify, I open the top vent then open the bottom screw and let it drain. Taking a look at the resevoir to see if it drained or not may change the end of the procedure.<br /><br />1. If it DOESN'T drain out then I should...what?<br /><br />2. If it DOES drain out then I should...ditto?<br /><br />You guys all rock! Thanks for the insight and helpful info. <br /><br />To MM above, I gave some serious thought to a tow when the alarm didn't stop sounding. I checked my engine oil level several times, put my hands on both heads [warm, not hot], and watched the oil come out of the top vent just hours before getting on the water, so I guess I tunnel vision-ed and risked the limp back to the dock. If I had realized there was a resevoir to check I would've had one more reason to think about the tow. Anyhow, thank for your risk assessment, it makes me a better boater getting your advice.

Re: Audio warning drove me nuts yesterday?!?

Point taken... sorry for being harsh.<br /><br />I'd just top it off at the reservoir and keep a bottle of lube handy in the boat, just in case it drops. By filling it to the vent hole with the pump, you have already ensured that there are no air pockets in the important part. Actually, a bottle of lube is a good thing to keep in the boat anyway.

Re: Audio warning drove me nuts yesterday?!?

If it doesn't drain out! Don't worry it will, gravity is a wonderful thing.<br />But if it doesn't, then you have something plugged or disconnected somewhere, at that point, post a question.<br />If it does drain, disconnect the hose and wires and clean the sludge out of the bottom of it with solvent or diesel fuel (whichever you have or is cheaper).<br />If the drive has been filled to the vent and the vent and drain plugs reinstalled (with new gaskets of course), then put some gear lube in the reservoir to the full line and call it good.<br />That air bubble in the drive will eventually burp into the reservoir and the level will drop a few ounces. Then top it back up to the full line so you can see if it ever drops again.<br />Alpha drives were run for years without reservoirs and worked fine. It's not so much the drive is clear full as it is a visible means of seeing if there is an oil leak (level drops) or a water leak (lube turns milky)<br />Most people think it's just a super critical filling process to get the air out, and it won't. That hose to the reservoir will allow the airbubble in the top of the drive. Only time and running will get rid of it.

Re: Audio warning drove me nuts yesterday?!?

Have a question about the reservoir........<br /><br />If there was water in the gear oil, would it be evident in the reservoir?<br /><br />I would think that the water would settle to the bottom of the drive.......

Re: Audio warning drove me nuts yesterday?!?

Yes, Tony, it will be noticed. The level expands and contracts. With the Merc Hi Performance gear lube you will see a milky color developing when water gets in the drive. May not happen as fast as in the drive, but it is noticable after a few runs.

Re: Audio warning drove me nuts yesterday?!?

Good to know.........

Re: Audio warning drove me nuts yesterday?!?

Good to know.........

Re: Audio warning drove me nuts yesterday?!?

Well, that was it. The resevoir was empty so I drained the drive unit again, refilled from the bottom and then filled the resevoir back up to the fill line and had a lovely boat outing with my bride Betsy (yep, I'm the JoJo). The JoJoBetsy II didn't give out a single audio peep. You guys rock on this forum and I hope I'm able to help others like I've been expertly helped here.<br /><br />Be safe,<br /><br />jb