Volvo Penta 3.0 water temperature

[lashke]

Hey guys, need your opinion on this. This past fall and spring I did some work on my boat to get it ready for the water. I changed all the oils and new impeller. My system is the raw water type. There was one small piece of one impeller fin missing and I couldn't find it. I looked in the thermostat housing and bypass and disconnected most of the hoses. No luck. I did notice the thermostat spring frame was broken on one side so I ordered a new one. Took the boat out and everything ran great. The next weekend I got in the new thermostat and replaced it. When I took the boat out afterwards I noticed it running hotter. (around 180-185 per the gauge) It stayed around there at idle and full throttle. I tested the stat when I got home and it seemed ok but I ordered another one anyway. When it came in I tested it side by side on the stove and the newest one opened faster than the other, so I figured that the first one must be defective. So, I installed the second one but the temperature still went up to 180-185. I tested the thermostat housing with a cheap no-contact temp. gauge and it was only around 165 deg. Then it dawned on me that the original thermostat was broken and was probably bend open and would let the water flow easier and therefore kept the temperature lower. Does this make any sense? Is 180-185 too hot for that engine? Thanks

 

[NYfourwinns]

Re: Volvo Penta 3.0 water temperature

180-185 is nothing to worry about. I don't think we have high precision instruments on boats, so +/-5 degrees is normal. It also may very with load and water conditions.

It's amazing nobody bothers to answer such a trivial question.

 

[Don S]

Re: Volvo Penta 3.0 water temperature

What was your engine temp running at before. If, after your repairs, the temp went noticeably up in temperature you have a problem.
180 to 185? will not hurt the engine, but it's not normal for a raw water cooled engine to run that high, even with a 160 thermostat.

 

[lashke]

Re: Volvo Penta 3.0 water temperature

It did run cooler before, but the thermostat in it was broken. The metal frame piece that holds the spring in place was corroded and one side had broken loose so that the spring was bent over and probably wasn't ever totaly closed to begin with. It was only after putting in a new thermostat that I noticed a rise in temperature. Oh, and btw the day I took it out was also the hottest day I ever been on the river. We live in Louisiana and it was close to 95 degrees that day and had been near 100 degrees the previous days.