HPDI overheating

[512]

OK guys I need a little help. I have a 2006 HPDI 225 with 315 hrs. Since I bought this boat 6 yrs ago I have said that it didn't cool right. I have had overheating alarms sporadically so installed the hyperlink cable to see water temp. I am pretty careful not to let it overheat, but it seems this motor will not idle without overheating. Only way not to overheat is with motor trimmed all way down. Trimmed up at idle the pee stream gets real weak. I have had it in the shop 4 times for filters and impeller and mentioned it all 4 times and was told nothing was wrong. Does this sound right or am I expecting too much to not overheat while idling? Water pressure at idle is around 2 psi and running is 10-12 psi. Operating temp while running is 130°-140°. Already changed water pump and housing and poppit valve. Thanks for any advice or insight to a possible solution.

[Charlie206]

What water pressure did you get while running back in the spring when the water was cool?

[512]

15-20psi I think. I know this past winter it would peg out the gauge. Honestly I pay more attention to the temp than I do water pressure

[Charlie206]

I guess I have more questions than answers. Trim angle should not affect temp at idle. And you are not expecting too much, there's no way you should get an overheat idling. What temp are you getting when you get the alarm?

[512]

I believe it goes off at 155°

[Charlie206]

I'd take it to a different shop for a water pump, and not just an impeller change.

[mcyama]

Charlie206 has the answer. I would want to verify if unit is getting hot. If you can, shoot engine crankcase with temp gun, near and under fly wheel by temp sensor.If you are a tec. Or old school and put your hand on it. But first splash or pour some water on the block if it steams or boils do not touch. Do not run unit on a garden hose to diagnose an overheating problem. Back down at landing is required.Thanks Martin

[512]

Thanks guys for the advice. I am hoping to get it in the shop this weekend. I believe it is either leaking from the water pump pickup tube or something screwy is going on with the thermostats.

[Charlie206]

Tstats are easy to check. Opening temp is stamped on them. Put in warm water and heat until they open, using a thermometer to check water temp. They should open around the stamped temp, probably something like 143.

[javelin90]

+1 on thermostats. I replaced mine two years ago. Very easy to replace them and before you install new ones also place them in pan on stove and make sure they open.
Garland

[512]

Well boat is back at the shop. Hopefully this time they can figure it out.