Oil Pressure Switch

[JT09]

I've got a 1998 5.7 MPI Mercruiser that I just pulled the motor to replace the timing gear cover. I was checking the safety switches and all seem to work including the lube oil resevior, temp switch, and oil pressure switch.

I noticed that the pressure switch did not close until a good 30 minutes after I shut the engine down. This is not normal is it? Shouldn't the oil pressure drop below 6 psi right after the engine has shut down and the oil pressure switch close?

 

[Don S]

Re: Oil Pressure Switch

Before I think about this too long, how did you determine it takes that long for the oil pressure switch to close? Do you actually set there with an ohm meter and a stop watch and time it?

 

[JT09]

Re: Oil Pressure Switch

Do you actually set there with an ohm meter and a stop watch and time it?

Well, I had my ohm meter hooked to it with an alligator clip and every ten minutes or so I would check it against ground. It takes at least 30 minutes. Didn't believe it at first so I checked it a few times.

 

[Don S]

Re: Oil Pressure Switch

Put in a new switch.