1997 Mercury 150 EFI Oil Alarm Question

[Greensleeves]

Hello all, I have a few questions, I was out over the weekend and I had an alarm go off. I checked the obvious and I had plenty of oil, the water flow was kinda sporadic out of the pee hole, so I let it cool and I still had an alarm. I just replaced the impeller last season and it always had a crappy flow but at high rpms it flows nice, is that normal or did I do something wrong? It worked all last season and this season this far though, so I figured it was ok. I got it home and I separated the wires where they terminate and the one that silences the alarm is the oil I believe because it goes to the module on top of the engine. Is there any way to test the sensor maybe cut the wires at the cap? but I would need to know if the sensor is normally open or closed though, or if you guys have any other ideas. I really appreciate any input or ideas.

Thanks,
Bryan

 

[Texasmark]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Look at the rear top of the engine with the cowl removed. On each water jacket is a cap with 2 bolts holding it in place. If there is a 3/8" black reinforced rubber hose connected to this cap your "pee" is plumbed off your stat and what you said about flow is correct. Head has to get above 143F for significant water to come out unless you get to speed and the bypass valve opens.

On the sensor, I know the temp is a short to the engine block on alarm. I would guess the oil is the same as that is an easy way to design the system....temp is solid alarm, oil beeps.

Mark

 

[Greensleeves]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Ok well that makes me feel better with the cooling system. The alarm is a beeping and only when the engine is running, so I'm gonna unplug the cap and test it to see if I get continuity between them, if so then that would mean a bad cap right? I wonder if there could be another issue with the oil system?

Thanks,
Bryan

 

[Greensleeves]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Ok so I just replaced the fuel water separator and when I ran it on muffs no alarm, is that a cause for one to go off? But looking at the oil line going to the vapor separator it is only half full meaning I can see an air gap in the line, I'm wondering if the pump gear is bad??
Thanks
Bryan

 

[Greensleeves]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Bump, anyone have the same thing on their engine with the oil line?

 

[h2oboy83]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Mine does this too. 97 150 efi. Idk either. Replaced the oil cap and still the beep. No the steady alarm. My water pump is the same, 3 psi at idle, 10 psi cruising. Idk. It seems like its getting hot to me

 

[Greensleeves]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Well I got mine to stop like I said, but I'm unsure about the pump gear because the oil is not full feeding the vapor separator. I'm not sure if it's supposed to be or not I never took notice.
Thanks,
Bryan

 

[CharlieB]

Re: 1997 Mercury 150 EFI Oil Alarm Question

The rapid beeping of the oil alarm can be triggered by a # of things.

Oil tank on the motor not 'totally' filled. Start the motor, let it idle, loosen the cap on the tank and let it fill until oil just starts leaking out, tighten the cap.

The module also compares signal from the oil pump rotation sensor to the igntion signal from one coil, usually #4, when it senses a difference, the alarm sounds. The difference could be either a failing pump drive gear, sensor, or a mis-firing ignition. All must be checked to determine which, if any, are at fault.

Lastly, modules can go bad on their own.

All these must be checked, tested, and the failure PROVEN before making a decision to order any NON-returnable electrical part.

 

[Greensleeves]

Re: 1997 Mercury 150 EFI Oil Alarm Question

We'll the pump gear can be inspected by removing the two bolts that hold it on right? As for the module I was doing some searching and think I can figure that out. The oil reservoir is completely full I made sure it came up to the top. But I think it's kinda odd how when I replaced the fuel filter it stopped? Would the alarm sound if it had water in the system?

 

[h2oboy83]

Re: 1997 Mercury 150 EFI Oil Alarm Question

How are you gunna check the module?

 

[Greensleeves]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Try the search engine on the forum, I also believe it's in the similar threads box at the bottom of the page

 

[Greensleeves]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Ok, so after doing some searching I found that the sensor in the bottom of the fuel filter is also wired across the oil sensor. I hope that is true maybe some of you mechanics can verify, I thought I read that somewhere before. I'm going to order a service book for my engine I'm still a bit concerned about the oil pump because the line is not full again maybe a tech can chime in on that issue.
Thanks,
Bryan

 

[bjrrockwell]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Gonna throw my methods in as i had a similar problem with an alarm only above 1000 RPM. although i'm not familiar with fuel injection as i don't know a safe way you can do any of the running tests and risk that there may be no oil getting to the cylinders. With that disclaimer said if it only alarms when running i doubt it is the cap but you can just unplug the blue wire from the alarm module to the float sensor. if this stops the alarm the float is bad (this is a ground) when level drops the voltage grounds on the float switch and triggers the alarm. next check voltage going out to oil rotation sensor should be 12V i would think anywhere from 11-13 should be fine. Next test the signal in from the oil motion sensor (by removing the plugs, and flipping the kill switch) test the blue white wire coming from the motion sensor. With ignition switch on check voltage, should be about 5 volts every two rotations of motor. you can remove the two bolds and inspect the gear as well. while you have the plugs out rotate the motor by hand and inspect the entire gear around as a missing tooth or two will trigger the alarm. I have a 1998 mariner V-135 carb model so i was able to premix fuel and do the running tests. My issue is I am losing power on the Signal (green) wire above 1000 rpm so my oil injection is fine no moving on to ignition trouble. if you do run the motor you can jump the green wire to other cylinders (normally on 4, mine was on 2) and see if it silences the alarm. if so then you have an ignition problem but i quickly noticed that on mine as it ran like crap. I by no means am an expert but have found this forum VERY helpful and am only passing on knowledge i have received from here and hope someone more knowledgeable can address the water/fuel separator alarm. Thanks.

Brian

 

[h2oboy83]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Here's my theory on mine. The blue/white wire had hit the flywheel and grounded out. I checked oil tank its full and pumping. (not low oil) Inspected the pump drive splines which are good (pump is good). Checked the oil pump sensor, 11.5 on white, 4.5 on blue/white (not the sensor). Swithched the coil signal and still had an alarm (not the ignition). Im guessing the module got fried when the blue/white grounded out. Anything else I should check before ordering the $200 electronic part?

 

[bjrrockwell]

Re: 1997 Mercury 150 EFI Oil Alarm Question

hmm... i really hope someone else chimes in with more expertise than me. But that wire is supposed to ground out to cause alarm, so even if it did ground out it shouldn't have fried the module. also, watch ebay first or talk to someone who may have a replacement. i picked up one that I don't even need now for $70 on there (used) which i may be relisting to sell now anyway. Any further luck on fuel/water separator?

 

[h2oboy83]

Re: 1997 Mercury 150 EFI Oil Alarm Question

I unplugged the water sensor and no change, so thats not it. Plus its brand new (which I know, that doesnt mean anything lol) IDK for sure but from my research the module alarms when it doesnt get a signal pulse. The blue/white wire has a pulse that varies between 0-5V. So if it grounded out it would set the alarm, but since it was still trying to send a signal of 5v while it was grounded to the block I think it might have messed up the module. Especially since everything else checks out. But im open to new ideas, Im ready to fish

 

[sschefer]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Step back a bit, the only thing different that I can see is the temp of the engine. The first time the alarm lit off you were running it in the water and from what I can tell all the other testing has been on muffs. The tell tale stream should be strong at idle on that motor, it should not be sputtering. Water flows at any temp normal op temp is 130-135. These are high volume pumps (tall, short vanes) and they pump an amazing amount of water at 650 rpm. I would buy a full water pump kit (50.00) and replace everthing according to the shop manual and see what happens.

The air bubble in the clear oil line at the pump is normal don't fret it. They put the clear line on there to detect a no oil situation, the bubble indicates that you have oil. If you have the shop manual you can follow the pump test procedures and sometimes it will purge the bubble out and sometimes it doesn't.

 

[Greensleeves]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Thank you I was worried a out the oil in the line, it's only about half full so it's a big bubble but it never gets empty. I will have a shop manual on order by the end of the week I just didn't get time. I got the alarm to stop with the new fuel filter so I must have gotten water in the system. I'm gonna take it out this weekend and hope all is gonna be well.

 

[bjrrockwell]

Re: 1997 Mercury 150 EFI Oil Alarm Question

Fabulous... great to hear. now if I could just figure mine out....