Mercury Guardian “limp mode” issue

[BBERK]

2017 Nitro Z-18 with Mercury 175 HP.
Usually at night when I am slowly accelerating without planing out, the warning alarm sounds with intermittent beeps and the motor goes into protection limp mode.
New impeller, stream is strong, oil reservoir is 3/4 full.
Could possibly be showing low oil level when the reservoir is at an angle?
Once I cut back to idle and plane out, it recovers fine. Any suggestions?
Thank you. BB.

 

[Husker525]

Can you pull the code that is showing up? That would give you a starting point. I have seen a few issues with oil level sensors but a code would give you the direction to go. It could be an oil pump issue, and have you checked for any oil leaks? There are YouTube videos that may be able to help you diagnose your issues as well, depending on the beep pattern. VesselView is a great way to connect to your motor, as it will tell you DTC's or Diagnostic Trouble Codes. It is a great investment and worth the money.

 

[BBERK]

I am on it! No oil leaks and I truly appreciate your response. Researching Vesselview now.
BB.

 

[iveysbodyshop]

I am on it! No oil leaks and I truly appreciate your response. Researching Vesselview now.
BB.

 

[iveysbodyshop]

I had similar issues with my 2015 150 pro xs.
I changed all the easy stuff that I thought and people told me might fix it… no good
Finally got a boat shop to run scan .
The float in the motor mounted oil tank had broke and it wasn’t reading the oil level correctly. New oil tank and all was good

 

[Ben]

I had similar issues with my 2015 150 pro xs.
I changed all the easy stuff that I thought and people told me might fix it… no good
Finally got a boat shop to run scan .
The float in the motor mounted oil tank had broke and it wasn’t reading the oil level correctly. New oil tank and all was good

Had the same issue, like the other response had a bad sensor/float in engine mounted oil tank. 2008 mercury 150hp efi

 

[ph411tx]

Can you pull the code that is showing up? That would give you a starting point. I have seen a few issues with oil level sensors but a code would give you the direction to go. It could be an oil pump issue, and have you checked for any oil leaks? There are YouTube videos that may be able to help you diagnose your issues as well, depending on the beep pattern. VesselView is a great way to connect to your motor, as it will tell you DTC's or Diagnostic Trouble Codes. It is a great investment and worth the money.

Husker525 I second your opinion about VesselView, it's similar to having an OBD2 code reader for your car, plus you get the cool readout when you're on the water.

 

[BBERK]

Can you pull the code that is showing up? That would give you a starting point. I have seen a few issues with oil level sensors but a code would give you the direction to go. It could be an oil pump issue, and have you checked for any oil leaks? There are YouTube videos that may be able to help you diagnose your issues as well, depending on the beep pattern. VesselView is a great way to connect to your motor, as it will tell you DTC's or Diagnostic Trouble Codes. It is a great investment and worth the money.

 

[Meerkat]

There is a sensor in the onboard tank that will put you into limp mode if the oil level in the onboard tank is low. That sensor sometimes goes bad. Check the on-engine tank when the engine goes into limp mode. If the tank is full, you probably have a bad sensor in the on-engine tank. You cannot change the sensor, just replace the tank. The OEM tank is about $250. Pretty easy to change but remember to put the motor back into break-in mode when you are done.
If the on-engine tank is empty, check the reserve tank. There is a filter on the intake for the motor that does get plugged. The main motor pressurizes the reserve tank which pushes oil to the on-engine tank & if the filter is plugged (which happened to me) the oil will not be getting to the on-engine tank. Pull the filter and wash it with carburetor cleaner.
On some models there is a float in the reserve tank but that float does not connect to the motor itself and will not put you into limp mode. It is to give a reading of reserve tank oil level to a dash instrument.
It is the sensor in the on-engine tank that puts you into limp mode.

 

[Joe Winkler]

There is a sensor in the onboard tank that will put you into limp mode if the oil level in the onboard tank is low. That sensor sometimes goes bad. Check the on-engine tank when the engine goes into limp mode. If the tank is full, you probably have a bad sensor in the on-engine tank. You cannot change the sensor, just replace the tank. The OEM tank is about $250. Pretty easy to change but remember to put the motor back into break-in mode when you are done.
If the on-engine tank is empty, check the reserve tank. There is a filter on the intake for the motor that does get plugged. The main motor pressurizes the reserve tank which pushes oil to the on-engine tank & if the filter is plugged (which happened to me) the oil will not be getting to the on-engine tank. Pull the filter and wash it with carburetor cleaner.
On some models there is a float in the reserve tank but that float does not connect to the motor itself and will not put you into limp mode. It is to give a reading of reserve tank oil level to a dash instrument.
It is the sensor in the on-engine tank that puts you into limp mode.

Si how do ya reset the motor to break in mode?

 

[Meerkat]

Here you go....
If you mess with the oil system, make sure you bleed it properly and re-set the motor to "break-in" mode.
From Bass Boat Central:
How to BLEED the ENGINE MOUNTED OIL TANK
1. Ensure that the BOAT tank has adequate oil in it (1/3 or higher level).
2. Verify all caps on the BOAT tank are TIGHT, and o-rings are in place under the caps.
3. Remove engine cowling, and set engine trim to "level-trim".
4. If you've OPENED any part of the oil system, or suspect air may be trapped in the lines, utilize a Turkey Baster or Syringe to "suck" some oil out of the ENGINE mounted tank (usually want the level down about 3/4" to 1" FROM THE TOP OF TANK for best results).
5. With cooling water supplied to engine, start engine and allow it to idle.
6. Loosen the cap on the ENGINE MOUNTED oil tank (approximately 1-1/2 turns). Allow the engine to continue idling, and watch carefully for the oil level to rise. This is a "pressure fed" system, so oil is being "pushed in" as air is being "released" through the cap. This may take only seconds, or as long as a couple minutes.
7. As soon as oil begins to "spew" from the cap, snug it down (don't overtighten- it will break/crack).
8. Wipe up all spillage.
9. IF you have repeat occurrences of this problem, you will need to have the system checked for air leaks, faulty check valves, etc. (Same would be the case if the system does not bleed as above described).

From Mercury:
Priming Optimax Oil Injection Pump: (Required after replacing Oil Inlet Hose Filter)
Connect water to the motor (for running it).
Make sure remote oil tank is filled & caps are on tight
Loosen the vent cap on engine mounted oil reservoir (don’t remove it – just loosen it)
Fill the engine fuel system with fuel. Connect the fuel hose and squeeze primer bulb until it feels firm.
Make sure “kill switch” is on (motor will run)
Turn ignition key switch to “ON”.
Within 10 secs move remote control handle from neutral into forward gear 3 to 5 times.
This starts priming process which may take a few minutes (you will hear the oil pump ticking)
Start and run the engine till oil overflows the engine mounted reservoir tank
Turn off engine and tighten the engine mounted oil reservoir cap.
It also resets the engine break-in period (more oil for 2 hrs of running)
Hope this helps...

 

[Joe Winkler]

Here you go....
If you mess with the oil system, make sure you bleed it properly and re-set the motor to "break-in" mode.
From Bass Boat Central:
How to BLEED the ENGINE MOUNTED OIL TANK
1. Ensure that the BOAT tank has adequate oil in it (1/3 or higher level).
2. Verify all caps on the BOAT tank are TIGHT, and o-rings are in place under the caps.
3. Remove engine cowling, and set engine trim to "level-trim".
4. If you've OPENED any part of the oil system, or suspect air may be trapped in the lines, utilize a Turkey Baster or Syringe to "suck" some oil out of the ENGINE mounted tank (usually want the level down about 3/4" to 1" FROM THE TOP OF TANK for best results).
5. With cooling water supplied to engine, start engine and allow it to idle.
6. Loosen the cap on the ENGINE MOUNTED oil tank (approximately 1-1/2 turns). Allow the engine to continue idling, and watch carefully for the oil level to rise. This is a "pressure fed" system, so oil is being "pushed in" as air is being "released" through the cap. This may take only seconds, or as long as a couple minutes.
7. As soon as oil begins to "spew" from the cap, snug it down (don't overtighten- it will break/crack).
8. Wipe up all spillage.
9. IF you have repeat occurrences of this problem, you will need to have the system checked for air leaks, faulty check valves, etc. (Same would be the case if the system does not bleed as above described).

From Mercury:
Priming Optimax Oil Injection Pump: (Required after replacing Oil Inlet Hose Filter)
Connect water to the motor (for running it).
Make sure remote oil tank is filled & caps are on tight
Loosen the vent cap on engine mounted oil reservoir (don’t remove it – just loosen it)
Fill the engine fuel system with fuel. Connect the fuel hose and squeeze primer bulb until it feels firm.
Make sure “kill switch” is on (motor will run)
Turn ignition key switch to “ON”.
Within 10 secs move remote control handle from neutral into forward gear 3 to 5 times.
This starts priming process which may take a few minutes (you will hear the oil pump ticking)
Start and run the engine till oil overflows the engine mounted reservoir tank
Turn off engine and tighten the engine mounted oil reservoir cap.
It also resets the engine break-in period (more oil for 2 hrs of running)
Hope this helps...

Thought that was the reset, but wasn't sure, as I now have a long buzzer alarm 10sec after I start the motor. Thinking it's telling me to reset motor, I had oil residue on top of my bilge tank, leak in seam under handle. Oil residue in the cable/hose flex cover to motor. Oil supply line splice seaping/leaking. I replaced the complete oil system including both tanks. Thanks for your help! JoeWinkler