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mlange

Engine alarm sounding

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mlange

The alarm went off today after taking a couple of passes at WOT. All guages were fin - oil pressure around 60 and engine temp between 160 and 165. I've never had any issues with the alarm before and the owner's manual does a pretty poor job of documenting it. The alarm is basically just a half-second beep, half-second quiet, half-second beep, etc...

Anyway, I thought this would be a good oppurtunity to get the information on TMC.

Doing a search on MBO provided that it could be one of the following things:

1. Knock sensor

2. Oil pressure switch.

3. Transmission temp sensor.

4. Engine temp sensor.

It sounds like the way to troubleshoot this is to disconnect each sensor one at a time after the alarm sounds until it goes off.

Are there any other things that it could be?

Thanks,

Mike

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jgouveia3

also look at your oil sender. mine was bad 2 years ago, and I got the same alarm. when looking at the sender, the "weep hole" was weeping. picked up a new what at the dealer (was still under warranty), swapped it out, and the alarm went away.

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Wkerat

Looks like you have it covered. I had that problem once and it was the oil sensor, but that was coupled with an erratic gauge reading.

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RTS

To troubleshoot the oil pressure switch (not sending unit, as you said your guage was reading fine), run a wire from the switch wire to any ground while the engine is running. If the alarm stops, thats your problem. This swich just sends a ground signal to the ECM. So just disconnecting and reconnected the switch wire will not allow you to troubleshoot.

I recently had the switch fail, and watched the service guy while he did the trouble shooting. If that's your problem, its an easy fix.

BTW, the alarm was beep,beep,pause,beep,pause,repeat. It would start about 15 seconds after engine start up.

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mlange

Ok, unfortunately I'm lacking on knowing where everything is. I know where the knock sensor is, but not the others. Anyone have a picture of where the others are on a Monsoon?

Thanks,

Mike

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mlange

Forgot to mention... I'm wondering if a bad ground somewhere would cause this as well.

I noticed when idling in that the the fuel gauge was down around 1/4 (I had a full tank). While I continued to idle the gauge went back up to full.

Mike

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SacRiverRat
While I continued to idle the gauge went back up to full. 

Wow, I wish that would happen to me... My gas gauge seems to only go one way Biggrin.gif

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RTS

Oil pressure switch is about mid-engine, low on the port side of my monsoon (2002, direct drive) near the filter.

Can't help you with anything else, I just know location of the oil pressure switch because I watched the tech on this particular issue.

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jgouveia3
To troubleshoot the oil pressure switch (not sending unit, as you said your guage was reading fine),

not neciissarily, mind read fine too, but it was the sending unit that was bad.

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BillFooter

I had exactly the same problem. My beeper would go off after a high speed run. Mine was the trans temp sensor. It screws into the top the transmission. To isolate the problem I made a high speed pass and then unplugged it while the beeper was sounding to make sure that was the source. I replaced the temp sensor and it never happened again.

Bill

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John M

A defective oil sender caused my alarm to go off last summer spoiling a nice weekend. The oil pressure and temperature were fine on the gauges. Once the sender was replaced everything was fine.

We had the sender replaced again as part of the summerizing of our boat two weeks ago.

Two weeks ago our dealer in Eagle River said they are having problems with Malibu oil senders. As I understand it, the oil sender is a part which monitors oil pressure. It uses a piezo electric sensor which monitors electrical signals proportional to oil pressure. These senders are real finicky and apparently report false positives indicating low oil pressure when in fact the oil pressure is fine.

I bet that is what is going on with your boat.

John

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HRemington

two years ago, mine was going off after a few minutes of running, then would go off after idling awhile. When I pulled the trans temp sensor it quit, so I knew I either had a faulty sensor, or the tranny fluid was indeed too hot. I felt the two hoses running to and from the cooler, and the one leading back to the transmission was noticeably cooler. When I disconnected it, no fluid was coming through. Replace cooler and solved problem.

Last year it started again. I disconnected water hose running to cooler, cleaned out some leaves and small debris, no problem since. I would check this first since it's easy and free. If not this, then figure pull trans temp sensor. If not that, go on to oil sender, etc.

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mlange

Ok, I ran out to the boat at lunch today, but couldn't get the alarm to go off.

However, I was able to play around with some of the sensors and test how they work a bit and have a few questions I'm hoping someone can answer.

First of all, I'm not sure which plug on top of the transmission is the temp sensor. On the port side (direct drive) there was an actual plug w/ two wires that could be pulled right off. On the startboard side there was a connector with two wires that screwed into it. Attached is a picture of the one on the port side.

Secondly, I'm not sure how to test the oil pressure switch. I was able to ground the oil pressure sender (to the gauge) and get the gauge to peg to 80psi. However, with the motor NOT started, just the key turned to the on position so that the alarm would sound, neither disconnecting nor grounding the oil pressure switch turned off the alaram.

Finally, although the screen on the trans cooler is completely free of debris, there was no noticeable different in temperature between the fluid taking the hose to the cooler and the hose taking the fluid back to the trans. Should there be enough of a difference that you can feel it?

Thanks for any help.

Mike

Edited by mlange

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VinRLX
Secondly, I'm not sure how to test the oil pressure switch.  I was able to ground the oil pressure sender (to the gauge) and get the gauge to peg to 80psi.  However, with the motor NOT started, just the key turned to the on position so that the alarm would sound, neither disconnecting nor grounding the oil pressure switch turned off the alaram.

Maybe out in left field here, but my oil p gauge does nothing at key on. My lcd also does not give me a low p warning--this function becomes active once started.

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SunriseH2OSkier
Finally, although the screen on the trans cooler is completely free of debris, there was no noticeable different in temperature between the fluid taking the hose to the cooler and the hose taking the fluid back to the trans.  Should there be enough of a difference that you can feel it?

I would sure hope so, otherwise the trans oil cooler wouldn't seem to be of much value. Had you run it much (in gear) before you did your check?

Edited by SunriseH2OSkier

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VinRLX

hi-jack on

Hi Hank! Hi Jerry! How's it goin?

hi-jack off

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mlange

Yeah, I ran a couple of passes at WOT and then checked the two lines. I would have expected the line going back to the tranny to be noticeably cooler.

Mike

Edited by mlange

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VinRLX

You're talking finger thermometer there, though. My Theory: Exterior of hoses will be of similar temp due to heat of engine; interior temp of fluid not discernible to the touch of Mike. Just a theory, though. If the wind slacks tomorrow or Sunday I'll crank the boat around a bit and see if I can substantiate.

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SmoothWaterMan

The wires on top of the tranny (that you can pull off individually) are for temperature. This is the first place to look with a condition such as yours, after ensuring that the tranny cooler screen is free from debris.

-Ensure that the knock sensor wire is actually plugged IN.

I doubt the oil pressure switches, since this happens only at WOT.

Peter.

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mlange

Thanks Peter!

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