2004 226 TE - Not building heat in motor

[fsts2k]

Hello,
Last year I noticed my 226 (about 390 hours) stopped building heat and appeared to be under cooling; it would not get much above 105 degrees. In March of this year I took it to the marina and asked them to put a new thermostat in. When I ended up getting the boat back (took a while to get pier in) we had a problem where the belt was not tight and the water pump was not turning. Long story that I am not doing justice to, the marina found that the impeller was gone. They put a new belt on, new impeller, and test ran it. I got the boat back and it is still over-cooling, I am getting about 113 on the engine temp, max 122 if I run it hard and then slow it down to idle. The starboard exhaust riser is warm to the touch like normal but the port is cool.

I talked to the marina and they believe the thermostat was new so it should be fine. They said their next step would be to pull the riser to see if calcium deposit is blocking one of the water paths.... I am a bit skeptical.

I don't want to turn this into a pissing match against the marina, I am not super happy with the performance. That said, any thoughts on how to diagnose this? I almost wonder if the impeller gave up the ghost and there are pieces of it stuck in the "new" thermostat. Other ideas? Also, does anyone know where the thermostat is located on the Indmar engine? It is not the 375hp version, it is the 335hp (I believe). Can get spec if needed.

Thanks

[a0128]

Is the engine overheating or not getting hot enough? Your post is confusing. If the impeller was gone your engine would overheat almost immediately as there would be no water being pulled into the cooling path. The complete lack of a thermostat would cause your engine to run below operating temps. Hard to tell which specific scenario you are dealing with.

[fsts2k]

Sorry if it was confusing; thought the title explained the engine was not building heat. Let me try again:

The problem with boat at the end of last year and today is that it the engine is not getting hot. The engine only gets to 113 degrees. Specs and history say the boat should get to 160

Further information:
- I took the boat fixed at the beginning of this Summer, the marina put a new thermostat in. That was March of 2016
- When i got that boat back at beginning of summer (June of 2016) the belt was not turning. The boat water temp got hot (220) and burned up the belt.
- The marina took the boat back and told me they had to put a new impeller in it and a new belt (June of 2016)
- As noted above, boat still does not get hot, only 113. Currently the Port riser is cold, the Starboard riser is hot (Today). Note that the oil filter does feel quite hot

Further further information:
- I don't know why the belt wasn't turning when I got the boat back but I suspect they didn't tighten the belt tensioner
- I also find it weird why symptom was that boat was not getting hot enough originally only to have the marina tell me the impeller had exploded... The cause and effect are wrong
- This marina has been good in the past and most other marina's in WI seem to be pretty terrible.. it is hard to find a good mechanic

Does that help? The marina has told me they did put a new thermostat in. I have looked to try to pull it out to do the hot water pan but on a 226 it is hard to see where the thing is.

Thanks