Volvo Penta 4.3 GX 2009 overheating

[ltdannyboy]

Had my boat out yesterday and when I went to 90% throttle at about 4000 rpm's I got the audible alarm. Gauge was showing good oil pressure and around 160 degrees on the temperature. Turned the motor off for a few minutes. The motor temp went to 180 and stayed there. Cranked the motor up again after 15 minutes and the temperature came back to 160. Ran the boat back up to 4000 rpm's and after 5 minutes the audible alarm sounded again, with the temp still at 160. Waited another 15 minutes and started the boat. This time I stayed at about 3200 RPM's for about 30 minutes and no alarm. Seems like the higher RPM's are causing the alarm, but I see know temperature increase. On the second run at 4000 rpm's the boat did start slowing down on its on. Protecting itself I guess. I have read that there are situations that cause the audible alarm to go off when running. Oil pressure or motor temp. Any ideas out there? Thanks in advance.

 

[CV16]

I just had to replace the oil pressure switch on my 5.0 because it was sounding the alarm even though my gage read 60 psi. Autozone had one from an 80's Chevy for less than $10.

Edit: this is the one just above the oil filter. I pulled the wire off and got no alarm that way so I knew that was the switch I needed. I did check the pressure with another gage as well.

 

[jerryjerry05]

Any idea how many hours?
​Last time the impeller was changed?
Fresh or salt water?
​The overheat at higher speed usually means the impeller is worn out or the riser/manifold is clogged.

The temp going to 180 is normal.
No cooling water circulating.

 

[ltdannyboy]

150 hours on the motor. Plan on checking the riser/manifold tomorrow. Thanks.

 

[CV16]

Did it actually overheat or is it just an alarm?

 

[ltdannyboy]

I was watching the temp gauge the entire time and did not see any high temps. Could possibly be the temp switch?

 

[SLorg]

I was watching the temp gauge the entire time and did not see any high temps. Could possibly be the temp switch?

@itdannyboy, did you ever figure out what the issue was? I seem to be having the same issue. Thanks

 

[bruceb58]

@itdannyboy, did you ever figure out what the issue was? I seem to be having the same issue. Thanks

6 year old thread..start a new one.