Oil Alarm Woes......1987 150HP v6 BlackMax

Most of the regulars will remember me I am sure.

Had a few issues in the past weeks after buying my boat/motor that I'm getting figured out finally.

When inspecting the oil system (pulled pump out to check plastic drive gear on crank), I found that the lines from the oil tank under the cowl, and the line from the fuel line to the oil pump were shot. I dodged a bullet I believe! I replaced them, then had a hard time bleeding the air out of the line from the pump to the fuel line. Thanks to JMartin I got that on the first try after his tip! So I bled the oil pump again and carried on, I replaced the rubber o-rings on the boat tank, and ran the motor. I had oil pressure in the tank, so figured the checkvalve was ok. When I put the boat in the water the first time this weekend, I bled the oil tank under the cowl, I couldn't do that on the trailer because the motor is too close to the ground to get level. So all is well. Ran around the lake for 35-40 minutes and when slowing down from WOT my oil alarm turned on. So I beached it (gas was 50:1 in tank BTW) and began looking things over. I had read to change the wire for the alarm modual to a diff. cylinder number on the switch box to see if an engine miss was causing the issue. I did that, went from #2 to #3. No alarm while pulling skiers for about an hr, boat ran flawlessly. Swapped passangers and embarked on a 1hr idle up river, alarm on/off the entire way, motor smoking like mad, got out into the lake and drove it for another 2 hrs total (not all at once) and no alarm. Then it came back and was on almost the entire way thru the river, out in the lake it was off and good to go.

I marked the boat oil tank with a marker, I used approx 18 gallons of gas, and about 1.5-1.75" of oil out of the tank. Which is plenty I'm thinking. Cowl tank was full with no air in it, lines are full with no air, etc...

Sunday I put gas in the boat and didn't mix it. I know its getting oil. Ran the boat down the big lake for 10 miles with it on and off, sat for 6hrs at the party spot, then fired it back up, alarm was on most of the way up the lake, then have to idle to launch, it shut off and stayed off for the rest of the day.

I know I know...I need a book, I've tried to find a merc one online, I can't find them anywhere, I've also read that I don't really want a seloc one???

I tried to unplug the cap wires and the rotational sensor wires while the alarm was on, but I'm assuming that wouldn't make it shut off anyways? It didn't seem to change a thing.

Alarm modual shot? I've tried to check all the wiring I can, but can't rule out a loose connection, I just don't know what to look for. A piece of tape makes the alarm tolerable at least.


Sorry for the long post. Wanted all the details I could give to you guys in there.


Thank you!

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

I believe the alarm module also monitors engine temp. Are you sure you're not overheating?
You can download the service manuals very inexpensively. Several sites offer them. I paid 4.50 for the 1992 manual. 500 and some odd pages.
Just do a google search. I think I found it at Tradebit.

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

I've tried google for the manual. I can't seem to find one that has my model number listed. I will try some more.

Positive its not overheat. That alarm is BEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEPPPPP (I tested the sensor with hotwater, and by grounding it out).

The alarm I get is BEEP BEEP BEEP BEEP BEEP BEEP BEEP BEEP etc....

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

Maybe this will help. Don't know if it's applicable to an '87 or not but it worked on my '93 150 XRi.

Run the engine to recreate the conditions sounding the alarm. Do these tests while the engine is running and the alarm is beeping. Be careful- the flywheel is very close to your hand. Keep sleeves, watches and other objects that can catch on the flywheel away. Once the alarm starts, I would first unplug the blue wire from the oil reservoir cap. If the alarm stops, either the oil level sensor is bad or the level is low. Next I would disconnect the green wire going from the alarm module to the #4 coil wire terminal on the switchbox. If this stops the alarm, either the rotation sensor is bad or the pump isn't rotating. If the alarm does not stop reconnect the green wire and unplug the white and blue/white wires to the rotation sensor. If this stops the alarm, check for no spark on #4 cylinder. If the alarm does not stop disconnect the green, white and blue/white wires. If this stops the alarm, then either the pump is not rotating, the rotation sensor is bad, or no spark on #4 or the alarm module is bad. If the alarm still does not stop, disconnect the solid blue, blue/white, white, and green wires, if this still does not silence the alarm, then the alarm module is bad. You will single out a bad component in each step, eliminating each item as you go. You can check the rotation sensor by checking its output. Turn the key on, leave power wire connected and rotate the engine. You should get 1 pulse of 5 volts for every 2 rotations. You'll need to have the plugs pulled for this test so you can turn the engine safelt and easily.


UFM82

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

The previous owner of my boat disconnected the oil pump and the module. I just got the boat and haven't had it out but once. I just mix my oil in the tank.

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

http://www.iboats.com/Mercury-Marin...y 150 service manual_Advanced|-|Y254985581512

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

ufm82 said:

Maybe this will help. Don't know if it's applicable to an '87 or not but it worked on my '93 150 XRi.

Run the engine to recreate the conditions sounding the alarm. Do these tests while the engine is running and the alarm is beeping. Be careful- the flywheel is very close to your hand. Keep sleeves, watches and other objects that can catch on the flywheel away. Once the alarm starts, I would first unplug the blue wire from the oil reservoir cap. If the alarm stops, either the oil level sensor is bad or the level is low. Next I would disconnect the green wire going from the alarm module to the #4 coil wire terminal on the switchbox. If this stops the alarm, either the rotation sensor is bad or the pump isn't rotating. If the alarm does not stop reconnect the green wire and unplug the white and blue/white wires to the rotation sensor. If this stops the alarm, check for no spark on #4 cylinder. If the alarm does not stop disconnect the green, white and blue/white wires. If this stops the alarm, then either the pump is not rotating, the rotation sensor is bad, or no spark on #4 or the alarm module is bad. If the alarm still does not stop, disconnect the solid blue, blue/white, white, and green wires, if this still does not silence the alarm, then the alarm module is bad. You will single out a bad component in each step, eliminating each item as you go. You can check the rotation sensor by checking its output. Turn the key on, leave power wire connected and rotate the engine. You should get 1 pulse of 5 volts for every 2 rotations. You'll need to have the plugs pulled for this test so you can turn the engine safelt and easily.


UFM82

Click to expand...

UFM First off thanks for taking the time to help.

Here's what I've done so far.

I have un-pluged the blue wire from the cap while the alarm is going off. No change.

I have un-pluged the wires to the rotational sensor while running too (I think just the white one to get it to stop, and it doesn't). I have switched the wire from #2 to #3 with the alarm comming on with them on both places.

I have also taken the magnet out of the oil pump arm and fired the engine. Constant alarm sounds, throw magnet back in and alarm is off. So that tells me the rotational sensor seems to work fine.

The pump has to be rotating as I'm using oil, if its not rotating I would have burned it up by now. I talked to my Father In-Law and his 115 4cyl Merc. does this all the time, he said he installed a switch (I don't know what wire) to shut the alarm off, then flip it back on, and it won't come back for quite a long time. I'd rather not do this, in fact now that I know its getting oil good, I want the alarm to be right, so it doesn't throw me off if something does fail. Either that or I'll just delete the oil system I guess, but I idle a lot, so going 100:1 on injection keeps the smoke show to a minimum!

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

jmj120 said:

http://www.iboats.com/Mercury-Marin...y 150 service manual_Advanced|-|Y254985581512

Click to expand...

Thanks jmj120.

I know I can locate the Seloc manuals, but many members around here have said not to bother with them.

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

I wish the alarm was on all the time so I could do these tests with it running in the driveway or something. So hard to pull the little nuts off the switchbox to change that green wire on land let alone hanging off the back of the boat. Guess I'll just keep plugging along trying stuff when its running....

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

mxzeatr said:

Thanks jmj120.

I know I can locate the Seloc manuals, but many members around here have said not to bother with them.

Click to expand...

Ok. I looked at Tradebit, that's where I got mine for the xr6. As you said, I couldn't find one for your engine.

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

Thanks for trying. I've been googling and googling. I'll locate one eventually. I hope.

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

Take all that stuff off and pre-mix. Its gettin' old n less dependable anyway

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

Dukedog said:

Take all that stuff off and pre-mix. Its gettin' old n less dependable anyway

Click to expand...

I guess I don't understand why guys say that so much around here.

Its a proven system. The only thing that seems flawed is the plastic gear on the crank. If thats ok its very reliable is it not??

I've checked that, took the pump assembly out and rotated motor, everything looks new inside the tunnel for the pump arm. No wear marks etc.

Like I said, I idle around quite a bit, using 100:1 (or close to it) while idling is in my and my passangers benefit while cruising down/up the river.

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

Its just a choice of some like myself. I abuse tha hell out of my hot rods so one less thing ta give me a problem..............

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

I see your point for sure. I'd rather just have the system work right though since it's all there and seems to be working corectly except for the alarm.

If the alarm modual is bad, I'd consider running pre-mix since it is kind of expensive.

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

mxzeatr said:

I see your point for sure. I'd rather just have the system work right though since it's all there and seems to be working corectly except for the alarm.

If the alarm modual is bad, I'd consider running pre-mix since it is kind of expensive.

Click to expand...

Maybe DukeDog will give you a module that he's taken off.

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

Now that would be something. I'd even be willing to pay for one if the price was fair. I'm not sure what they go for new. But they must not be doing him any good???

Are you pointing toward a faulty modual too Jim?

Is there any wiring inside of the control box that I should be looking at? All the wires go into a very tightly wrapped loom all the way up into the controls, I can't believe there would be a problem inside that...But perhaps in the control? Its got me stumped.

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

Lets refresh the list a bit.

You say you're getting an oil alarm. Is it a steady tone, or a beeping? Steady tone is a short, a faulty module, or an overheat.

When you turn on your ignition, do you hear the 4 or 5 diagnostic beeps? Mine is one long and 3 short.

Is your battery in good shape? Is the ignition switch good for sure. The oil alert goes nuts on low or intermittent voltage.

Is there any other symptoms, like a slight loss of power when the alarm sounds? Cylinder #2 could be dropping.

Have you done the diagnostic testing on the oil pump sensor?

hope ait helps
John

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

Have you searched the old posts? Should be some with the specs. Some post about the module. A post about moving the one wire to cylinder 5. Post about switch boxes, sometimes switchbox will cause this, without causing the engine to misfire. The module compares the voltage between the switchbox and the pump sensor.


My guess module.

Re: Oil Alarm Woes......1987 150HP v6 BlackMax

j_martin said:

Lets refresh the list a bit.

You say you're getting an oil alarm. Is it a steady tone, or a beeping? Steady tone is a short, a faulty module, or an overheat.

When you turn on your ignition, do you hear the 4 or 5 diagnostic beeps? Mine is one long and 3 short.

Is your battery in good shape? Is the ignition switch good for sure. The oil alert goes nuts on low or intermittent voltage.

Is there any other symptoms, like a slight loss of power when the alarm sounds? Cylinder #2 could be dropping.

Have you done the diagnostic testing on the oil pump sensor?

hope ait helps
John

Click to expand...

The alarm I get is BEEPING.

I get a BEEEEEEP BEEP BEEP BEEP when I turn the key. Just like yours.

I can get the battery tested this weekend, however I do charge it before I go out every time.

I can only ASSUME that the ignition switch is fine. (How do you know? It works with no issues)

There seems to be no loss of power. The motor runs smooth at all RPM's alarm or not. I have put the 'GREEN' wire onto cylinder #3 to try that. Should I switch it to #5 as mentioned? Which switch box controls which cylinders?

The only testing I've done with the rotational sensor is to take the magnet out, and fire the motor breifly. Alarm was beeping constantly. Put magnet back in and no beeps. I do know now that I can take the plugs off and rotate the motor with the ignition 'on' two times to get 5v output.

I'm looking for a manual to trouble shoot. But I can't find one that covers an 87 150 for the life of me. I may just end up trying a seloc?