96 Merc 135 Beep Beep Beep oil injection system issue?

[BigJeff]

Here we go again, 1996 Merc 135 low oil beep beep beep started with the key in the on position but motor not running All oil levels good. Beep beep beep never stopped, parked it. Got home turned key no beep, ran on muffs for 10 min no beep and exhaust appeared to contain oil and more at higher rpms than idle. Replaced battery and beep returned, starting elimination process. Float, motion sensor, warning module, oil pump? Does this sound like module? Seems unlikly to be motion sensor or pump as alarme startes before motor even cranks over. I will follow up after more testing but anyone had similar case or ideas? Also odd that it went away, ran and then I switch battery and it comes back?

 

[Texasmark]

Re: 96 Merc 135 Beep Beep Beep oil injection system issue?

I don't have a manual on a 135. Assume a V6. On the inline engines, if power is on (the key is on), the oil module (that you seem to have) is energized by the purple wire with 12v and can deliver a modulated tone for oil related problems. The source of the beeping is the module and it is activated by a short between two wires coming from the oil level switch which closes when the oil level is low. The oil level switch is a spst switch and has no way of producing a modulated tone on it's own....it is either shorted when indicating a fail or open when not.

What you might do is to pull the connector on the module and looking into the wiring harness direction, ohm across the two wires. The two wires are light blue on smaller engines, maybe the same color if on yours. Easy way to tell is that there are two wires of the same color going into two separate pins of the oil module connector.

If a short, you have the cause of your alarm and just need to see what's causing the short....could be a pinched wire, low oil level, malfunctioning switch, if like the lower hp engine oil tanks, the sense magnet could have fallen off for starters. If an open circuit, then your module would probably be at fault. Simple as that.

Mark

 

[BigJeff]

Re: 96 Merc 135 Beep Beep Beep oil injection system issue?

Mark, Thanks for the info, I barrowed a multimeter from a freind but still not positive on setting and how exactaly to test ohms or volts any tips on that part?

 

[BigJeff]

Re: 96 Merc 135 Beep Beep Beep oil injection system issue?

Then started testing the motion sensor and white lead from module measures 12 volts, but the blue/white sensor lead reads 0 when the using emergency start rope to rotate crank. Service manual says bad sensor or pump at this point. Could not find a sensor before some places where close trying again in the morning.

I still think it is odd that the buzzer stopped for no reason then after changing the battery it came back???

 

[ripperace]

Re: 96 Merc 135 Beep Beep Beep oil injection system issue?

Big Jeff. This is similar to my problem (now several threads down). I get the constant beeping, all levels are OK, but I get a CONSTANT 4.96 volts from the blue/white wire, regardless of crank position, and I know the oil pump is turning. I'd say bad sensor or module. Except the Merc bible doesn't give anything as to my issue.

Ripper

 

[BigJeff]

Re: 96 Merc 135 Beep Beep Beep oil injection system issue?

I had 5.01v on the blue/white coming from the module but nothing form the one with the sensor and I had the ground and white still attached.. Yours read a constant 4.98v on which side of that connection sensor or module?

I still have not found a way to test the module, I need to get a little smarter with the wiring diagram to check that other than running the boat on mixed and metering the oil output from the pump. Not sure even where to find a graduated cylinder to measure with.

 

[ripperace]

Re: 96 Merc 135 Beep Beep Beep oil injection system issue?

The merc book says to check voltage on the white wire, which should be 12 volts. Mine is. Then it tells you to plug that back in, and check voltage on the blue/white while it's still connected, which is reading 4.96. According to the book, that voltage is supposed to vary, which makes sense to me as that sensor is reading the magnets rotation in the oil pump coupler. The only other checks it tells you about is the green wire from the power pack, the float in the reservoir check (continuity) and then the drive system, which I've already checked. I ended up getting a rotation sensor and it should be here Friday. I figure that'll be the cheaper alternative to the module itself, which is almost $200.

Ripper

 

[Marathon Man]

Re: 96 Merc 135 Beep Beep Beep oil injection system issue?

A good trick for measuring oil to add to fuel tanks is to use an empty Stabil or similar plastic bottle that lets you easily measure and then add the correct amount of oil.

 

[BigJeff]

Re: 96 Merc 135 Beep Beep Beep oil injection system issue?

I did not have the blue/white connected while testing, I will need to give that a try, I just replaced the motion sensor yesterday and may be I have been testing it incorrectly. The service manual read to test the senor lead and does not mention that is hooked up. The white is plugged in and it is grounded, I was just testing the sensor end of the blue white, the module side of the blue/white was reading 5 volts constant and the blue white was nothing before and after I replaced it. The wrench at the shop I bought the part from said to confirm the pump is turning removing the oil pump and holding my finger on the end of the gear and pulling it over to confirm it is turning and it is turning. I have also read on other posts that people had plastic shavings on the gear when they removed it and I did not have any. I am wondering if it the module then but I don't want to keep pouring in money. I am debating on taking it in and writing the check.

New twist after talking with shop again, the float sensor can check out but the float it self can get saturated and actually sink to deep to set off the alarm. Going to chase it more Friday night.

 

[BigJeff]

Re: 96 Merc 135 Beep Beep Beep oil injection system issue?

Beeping Gone, replace warning model after testing everything else. Heated the module with a hairdryer no luck but then we froze it and we got the beeping to stop. Replaced and everything appears good.