2008 Volvo 5.7 Gxi J Alarm

[low timer]

Good morning. I have a 2008 Volvo 5.7 Gxi J setting off the warning alarm. Yesterday while cruising down the lake around 15 minutes after leaving the dock, my alarm started sounding a continuous beep and entered protective mode. Shutting down and restarting the motor would allow another short travel time. We floated around for about 10 minutes, restarted the motor and drove for about 5 minutes before the alarm. I began to troubleshoot and found if I left my port side riser temperature sensor disconnected, I could operate the boat without any alarms. I didn't have an IR temperature scanner to read the actual temperature of the riser, but could comfortably leave my hands on both risers with the starboard riser actually feeling slightly warmer (riser with working sensor). The boat has 234 fresh water only hours, do these sensors fail often or should I be looking at another problem?

Next question, if you don't mind. While troubleshooting the alarm, there are two sensor on the port side of the motor toward the bottom of the block I would like to positively identify. One sensor is to the rear of the block and the other is forward approximately one cylinder below the manifold. If my memory is correct, the rearward sensor has three wire connector and the forward sensor was a single wire connector. I've spent the morning looking for an exploded view to identify these two sensors without any success.

Appreciate the help

 

[spoilsofwar]

What GXi-J? 4.3, 5.0, 5.7, 8.1?

 

[low timer]

What GXi-J? 4.3, 5.0, 5.7, 8.1?

I'm sorry, an oversight on my part. I have a 5.7 and will edit the post.

Thanks

 

[muc]

Volvo has 2 different exhaust temp sensors, the first design was adjustable (you can tell if yours is this style by looking at the stud the wire connects to - it will have a slot that you can put a screwdriver into to adjust it) they had some troubles with this sensor getting out of adjustment and switched to a new nonadjustable sensor. Sounds like you should replace the failed sensor.

My guess is the rearward sensor is for oil pressure, and the forward sensor is the knock sensor.

 

[low timer]

Volvo has 2 different exhaust temp sensors, the first design was adjustable (you can tell if yours is this style by looking at the stud the wire connects to - it will have a slot that you can put a screwdriver into to adjust it) they had some troubles with this sensor getting out of adjustment and switched to a new nonadjustable sensor. Sounds like you should replace the failed sensor.

My guess is the rearward sensor is for oil pressure, and the forward sensor is the knock sensor.

Thank you very much for the information on the sensors. I will pull the temp sensor and replace.

Thanks again.

 

[low timer]

Volvo has 2 different exhaust temp sensors, the first design was adjustable (you can tell if yours is this style by looking at the stud the wire connects to - it will have a slot that you can put a screwdriver into to adjust it) they had some troubles with this sensor getting out of adjustment and switched to a new nonadjustable sensor. Sounds like you should replace the failed sensor.

My guess is the rearward sensor is for oil pressure, and the forward sensor is the knock sensor.

Good evening, thought I would provide an update to my problem, it's solved. I had disconnected the wires from the riser temp sensors one at a time to isolate the problem sensor. I indeed had the adjustable sensor, which I replaced with the newer style of temp sensor. Changing the temp sensor solved my alarm problem.

Thanks for the help everyone provided.