2000 5.0 gi low oil pressure at idle

[Mwright7]

After running at 4200rpm for about 30-40 minutes and dropping down to idle my oil pressure dropped into the red and my audible alarm sounded. It seems heat related because I ran a shorter distance the other day and the oil press was low but not in the red after coming to an idle. I changed the oil with 30w and replaced the oil pressure sender just for gp so that has been pretty much ruled out. The temp guage is a little on the high side, not sure if this is normal or not since I have only had the boat a few months. Hopefully someone can steer me in the right direction here.

 

[Don S]

Re: 2000 5.0 gi low oil pressure at idle

The temp guage is a little on the high side, not sure if this is normal or not since I have only had the boat a few months.

What are you calling "a little on the high side" ? We can't see your gauge, so numbers would help. What is the full model number of your engine? Need those letters after the 5.0Gi.

 

[Mwright7]

Re: 2000 5.0 gi low oil pressure at idle

What are you calling "a little on the high side" ? We can't see your gauge, so numbers would help. What is the full model number of your engine? Need those letters after the 5.0Gi.

It's a GI PEFS. For the temp guage, unfortunately my guages do not have numbers, but if it were a fuel guage it would be up around the 3/4 mark.

 

[Don S]

Re: 2000 5.0 gi low oil pressure at idle

Get a mechanical gauge and hook up to your oil pressure so you can actually see what it is. It is probably low, since the gauge and the alarm are both saying the same thing, but they are both electrical and on the same circuit. Also get one of those IR temp guns and check the temp right next to the gauge sending unit so you can see what the gauge should be saying.

 

[Mwright7]

Re: 2000 5.0 gi low oil pressure at idle

Get a mechanical gauge and hook up to your oil pressure so you can actually see what it is. It is probably low, since the gauge and the alarm are both saying the same thing, but they are both electrical and on the same circuit. Also get one of those IR temp guns and check the temp right next to the gauge sending unit so you can see what the gauge should be saying.

Will do. I'll post numbers when i get them. Thanks

 

[Mwright7]

Re: 2000 5.0 gi low oil pressure at idle

Update: problem solved. After speaking to a long time boat mechanic in the area I switched from 30w oil to mercruiser 25-40. Ran her hard friday and no problems.