Oil Pressure Alarm

[Joey9851]

The shop is working on getting my new to me motor installed (2019 Mercruiser 4.3) and is having an oil pressure alarm issue. The original motor was a TKS and it’s being replaced with an engine without TKS (bought the engine with 5 verified hours for $1600 instead of $11,000 from mainland). The tech is going to diagnose next week but curious as to what direction you all can point me in so I’m not getting screwed on labor costs (already way over my budget). I have an oil sending unit in a box at my house, and the tech had to splice the engine to hull connector to get the motor installed correctly. Anything else to look for? I had them change the oil and all filters as part of the job too

 

[Fun Times]

Are both engines complete MerCruiser engines including all sensors and accessories/hardware/wiring,etc. or are certain parts being switched over to make the other work, etc.?

Is the other (new) engine carburetor or MPI?

Do you happen to have the MerCruiser serial numbers to either the new or both if parts are being swapped around.

Did the oil alarm come on before or after the new oil filter was installed?

tech had to splice the engine to hull connector to get the motor installed correctly

Any other details to share on this procedure?

 

[04fxdwgi25]

I would install a cheapie ol mechanical oil pressure gauge in a "T" where the oil alarm sender sits, pull the spark plugs and spin it over with the starter.

That'll tell you if you have oil pressure / wiring problem or not and if it's just a bad sender or a bigger problem.

 

[Scott Danforth]

First, use the mechanical gauge to verify oil pressure

Second, the alarm is tied to oil pressure, gear lube reservoir, temp switch and a few other things. Trained marine mechanics will know this and be able to troubleshoot

Third....why not swap the motor yourself?

 

[Grub54891]

All the comments before are good. I've had customers who had alarms, a lot of times it's the drive reservoir float that is stuck from gunk. My usual service is removing the reservoir and flushing it out.