Oil injection Alarm - stumped

I have a 1997 200HP mercury EFI offshore and am having the oil alarm going off. The alarm is sounding even when the engine is not running.<br /><br />I've read the large number of posts and followed the suggestions such as making sure there is pressure in the tanks, oil is flowing, unplugging the cap sensor as well as the sensor on the oil pump.<br /><br />I made sure there were no air gaps, bleed the system at the pump, changed the orings on the caps to the tanks.<br /><br />I' sure there is oil flowing, i have smoke out of the exhaust. It's not running rough even at idle. Nor is it running hot. I've unplugged just about everything in the motor housing and the only thing that makes it stop is the power.<br /><br />I'm starting to think that either I'm crazy or the alarm buzzer itself may be shorted.<br /><br />I even drained and refilled the lower unit just in case. The water seperator is clean (both of them.<br />Any suggestions would be appreciated.

Re: Oil injection Alarm - stumped

Are you sure it's the oil alarm causing the problem or could be the temp. sensor is the culprit. Try unplugging the wire from the temp. sensor at the engine and see what happens. It could be the buzzer itself or possibly the ignition switch, also.

Re: Oil injection Alarm - stumped

I did try unplugging the heat sensor also even though the alarm is beeping instead of continuous.<br /><br />I'm going to try the buzzer itself next I guess. Thanks for the reply

Re: Oil injection Alarm - stumped

Have you verified oil flow by a) marking the in boat tank or b) checking flow to the mixing tee while running? If you're not absolutely sure you have oil flow, connect motor to a tank with premix while you do your checking. The Merc shop manual goes through a complete check list for oil alarm conditions. It can be very expensive to mistakenly assume the alarm is bogus!<br /><br />You say the alarm occurs even with the engine not running. Does this mean 'ignition off'? The alarm horn will normally sound continuosly when the switch is turned to the "on" position and for a few seconds after startup. This is normal.<br /><br />If you don't have an OEM shop manual, I would suggest getting one. I assumed I had a faulty alarm and almost fried a powerhead before I added oil to the tank ... then I found the oil pump wasn't turning (due to the drive gear on the crankshaft failing).

Re: Oil injection Alarm - stumped

I'm hooked up to an external tank now...after seeing all the posts, i definitely didn't want to blow anything.<br /><br />I do have flow, but I can't be sure that it's "enough"<br /><br />The alarm is ringing with the key in the on position. Doesn't sound when in the off position.<br /><br />I just got back from getting a shop manual so I'll start from the beginning.

Re: Oil injection Alarm - stumped

I would think maybe you have a faulty warning module. You seemed to have checked everything except coil voltage and according to my installation manual you need a DVA to check that. The book says that if the voltage is correct there, then the warning module voltage would be correct.<br />To check the low oil sensor, it says to disconnect both low oil sensor lead from the terminal connectors. Connect an ohmmeter between . There should be NO continuity thru the sensor. If continuity exists, sensor is faulty, replacy caps assembly. (OUCH!) They are $50.00, I have had to do 2 on mine.

Re: Oil injection Alarm - stumped

That's the next check I'm getting ready to do. Went out and got the shop manual last night and read through it. I'll post an update with the solution, but it seems its going to be the module.<br /><br />Thanks everyone!

Re: Oil injection Alarm - stumped

I dont know if this will help. but I just had to rebuild my buddies 96 200EFI for oil pump drive gear failure (he didnt hear it going off). <br /> Im not sure if they are the same setup, but his oil alarm was a beeping alarm, and his temp alarm was a constant alarm (no beeping). Just figured Id mention it.

Re: Oil injection Alarm - stumped

It's easy to pull the oil pump and inspect the driven shaft for plastic debris. If you find that, the pump is not being driven consistently and you will know the cause. If you find everything OK, you will certainly narrow the possible choices to a sensor malfunction or the warning module.<br />Good luck!

Re: Oil injection Alarm - stumped

I've followed through all the tests and it seems the conclusion is the warning module itself. I have one on order and should be here by Thursday (I hope cuz the fish are biting in the Chesepeake).<br /><br />I'll go ahead and pull the pump and check out the shaft also just to be sure. I had already unhooked the sensor on the pump and the alarm stayed chirping. Once I unhooked the wire from the warning module itself, the alarm stopped.<br /><br />I'm keeping my fingers crossed!

Re: Oil injection Alarm - stumped

Just got the warning module deliverd and just finished switching it out. Problem is solved!<br /><br />Back to the fishing now! Thanks for everyone's help!