oil pressure gauge maxing out

[JohnsonBargeMan]

Hi all.
I have a 1998 4.3L Mercury GM 262 V6. The oil gauge maxes out when going anywhere from half to full throttle. I've not had it out this year so don't recall what it does when idling. The alarm sporadically sounds also. I was going to go ahead and change the oil pressure sensor but thought I would ask here first for ideas to diagnose the rout cause.

(A mechanic at a marine said he doesn't think it is a issue and that the sensor is so far under the engine that it isn't worth work or worrying about it.....but I do worry!)
What are your thoughts?
Thanks

 

[Bondo]

The oil gauge maxes out when going anywhere from half to full throttle. I've not had it out this year so don't recall what it does when idling.

Ayuh,...... Welcome Aboard,...... It's a stone cold motor, of course the oil pressure runs high, when ya rev the snot out of it,.....

Did ya put the drive down, before ya started it,..??

 

[alldodge]

Get a mechanical gauge and install to check your pressure on the boat gauge.

When does the alarm sound off?

If it sounds off at idle you may have a low pressure issue. It can also be water temp or low drive lube

 

[JohnsonBargeMan]

Thanks for the input bondo. It stays pined when hot or cold. Drive is down.

Ill have to get back to you on the alarm Alldodge after then next time I take it out. Could you recommend a gauge and how/where to install it?

 

[alldodge]

It stays pined when hot or cold. Drive is down.

Remove the sender wire from the gauge, and if it no longer pins then its the sender or the wire. To check the wire, remove it from the sender to see if the gauge does not pin,

You have a sender for oil pressure, and a oil pressure switch for the alarm. The gauge sender is larger then the switch and about 2 inch diameter and is down low on the port side. The switch is below the distributor on the back of the motor.

How is the level in the drive lube, and has the lube bottle ever been cleaned out and refilled?

 

[JohnsonBargeMan]

Thanks Alldodge. I’ll do those tests this coming weekend.
The drive lube has a very small leak (from the hose) which makes the bottle need topping up once year (my next project). The bottle has never been cleaned.