What is the most likely cause of this overheat situation?

[true blue]

I have a 2006 5.7 Volvo I/O. The boat has gone into limp mode a few times, temp guage normal. Stuck a wire up the intakes , seemed to help (no limp mode). The engine temp rises sometimes 10 degrees from normal, usually at lower rpm's. Checked the riser temps, one was 115, the other 153. I had the risers off two years ago, risers and manifolds looked good. I use Nuetra salt every shutdown. What would be the most likely cause here or course of action?

 

[Don S]

Re: What is the most likely cause of this overheat situation?

Not much to go on here, do you have a full model number of your engine? or a serial number?
Going to assume it's an EFI engine and would guess one of the temp or pressure switches is failing.
Best thing to do is get it hooked up to a diagnostic computer to find which switch is telling a lie to the ECM.

 

[true blue]

Re: What is the most likely cause of this overheat situation?

This is a fresh water cooled 5.7GI-F ser.#4012191678

 

[true blue]

Re: What is the most likely cause of this overheat situation?

Also, why is the stasrboard riser 153 and the port 115?

 

[Don S]

Re: What is the most likely cause of this overheat situation?

Also, why is the stasrboard riser 153 and the port 115?

Normal. At low rpm, the pump puts out low volume, and low pressure. Water takes the path of least resistance and that side gets the most water. As rpms increase, that difference will get less and less.

Below are links to the EGC diagnostic manual and wiring diagrams. You are also going to need a diagnostic tool like this Rinda Scan tool http://www.rinda.com/marine/mtspec.htm#techmate . Without it, your chances of finding the problem goes to throwing a bunch of parts at it and hoping you hit on the problem.

http://www.4shared.com/document/LW5Yv4ge/7746872_EGC_Diagnostic.html?

http://www.4shared.com/document/0RMVKh23/7745609_Wiring_Diagram_06_Eng.html?

 

[true blue]

Re: What is the most likely cause of this overheat situation?

Thank you so much Don for your time and consideration. It really means a lot to someone having a liittl trouble.