454 Merc Engine Alarm

[craig]

Hi Everyone-

I'm rolling in a '98 22t and over the last month my engine alarm has been going off. If I slow the engine back to idle, it generally stops. I have experienced several "fixes": 1) slowing accelerating 2) flooring it

Facts:
-I have oil and oil pressure
-I can't confirm that the alarm goes off when the engine is cold or hot. (If I get it to stop then it requires that I either stop the engine or slow back to idle for the alarm to go off again.)
-If I disengage the throttle, I can rev the engine without the alarm going off - I can rev to 4k+ and she just purrs
-my lube is full (have yet to confirm if the float is moving [based on another post's recommendation])
-my TRIM up button isn't working but the trailer up button will raise the Bravo 3

Question: what is the likelihood that the trim button is the problem? Given my third bullet, I don't want to have the marina hook up the Merc engine diagnostics for a $150ish charge.

If this alarm doesn't get shut off, the wife might sink the boat.

Thanks in advance for reading!!!!!

[Big Block Power]

I wonder what your engine temp is.could have a bad t stat or impeller? Drive lube loves to turn on the alarm also.The sensor will stick in the tank. Mine was barely low and it set the alarm off.

[craig]

The temp is nice and low (120 - 130 degrees). While she's 18yrs old, this is the first season that she's been floating without a lift. Could the grime trigger this intermittent alarm?

[Big Block Power]

I wouldn't think so. But your temp seems awful low. Most run 165-170. Does it have a t stat in it if so what temp. I would think grime would unless it restricted water flow I the five to the engine? I think drive lube will turn on the alarm with oil pressure and temp. I can't find the merc info on this.I used to have it.

[Big Block Power]

Found it but I think it's to new for your engine package.

[craig]

The temp gauge is always showing less than 120, but I don't have single gauge that reads correctly. RPM never higher than 3k at 40+mph. Gas is off by 1/2 tank. Speedometer is rarely above 20. Can you adjust these using some type of adjustment knob?

[jhnmdahl]

If literally nothing is reporting right, it's going to be a lot more difficult to nail down the source of your alarm. Have any parts been replaced, and did everything start malfunctioning at about the same time? I might start by unplugging and replugging whatever sensors I can find, keeping in mind that low oil pressure, engine temp too hot, and low gear lube level are the main causes for the alarm.

John

[craig]

No changes in 15+ yrs. (knock on teak wood). I can't say for sure when the gauges went wrong. I'm hoping for gear lube....

[Big Block Power]

Check the dash ground. If there faria you would have to just buy new ones. Nothing to adjust them. The tach you can only switch it from 4,6,8cyl. Yep add or check the float in the lube bottle.

[craig]

Just to close this out... popped the hood and did a close inspection of all the fluids. Found that the gear lube bottle and the holder hide the true level and only if you look close can you read the level. Rookie level.

Thanks again everyone for your time!

[Big Block Power]

Yep good deal. It doesn't take much to set that alarm off from the drive lube.