High Temp Alarm

[Tapsy- Turvy]

2008 DF 250. New Impeller, T-Stats, and water pressure valve.. Getting a high temp alarm at LOW RPMs after HIGH RPM run. Has anyone experienced this and could it be a temp sensor based on this symptom? Any help is greatly appreciated.

[artdf175]

did you install the full impeller kit or just a new impeller?
there are reported problems not doing the full kit.
there have been problems from not getting the tube/gasket seated correctly on the water tube from the pump to the engine when reassembling
my '06 175 developed a corrosion hole behind to cover plate that has the fresh water rinse hose connection
this allowed fresh water to dump into the internal exhaust port and bypass being pumped through the head except at high Rpms
Art

[Tapsy- Turvy]

Full Kit. Great feedback thank you. Looking at the service manual trying to follow and find exactly where to look and what to check. Your last scenario seems closest to my issue. Runs fine at high rpms, then overheats at low rpms after running high. Any further detail regarding the location is much appreciated. Thank you again for your reply sir.

[artdf175]

were you having problems prior to the work ??
are you sure you the pump was installed with vanes right direction? Just asking questions
why did you change the water pressure valve?
I couldn't not find the hose bib fitting where you flush the head after running in salt waters

[Tapsy- Turvy]

I replaced full pump kit on both engines off season as preventative maintenance. Took the boat out for high rpm trial run when launched in may no issue. And no overheat coming into slip at low rpm. Second trip overheat at high rpm. Changed t stats as I intended to as part of PM. Problem went away. 2 trips later overheat at low rpm after high rpm run. Changed water pressure valve. Still same issue. May try swapping temp sensors. Also removing t stats to see water flow. Remove spark plugs to check for rust to rule out bad head gasket. All before I haul the boat.

[Tapsy- Turvy]

Hoping an experienced member can help me. Digging deeper. Found that low flow at low RPMs under load for sure. Starboard side of engine goes past 200 degrees while port side of engine remains low. Using an IR thermometer. Hauling the boat this week to inspect the new water pump. Hoping to find a popped hose? hopefully not an obstruction..ANY advice is appreciated. Thank you

[Freddy jakob]

Hello. Did you find out what causing this problem?

[Tapsy- Turvy]

Thanks for asking Freddy. When we dropped the lower unit it was very apparent that the water pump case bushing that sits directly on top of the pump was damaged. It got damaged when we were struggling to line the splines up with a little back and forth in the off season after replacing the impeller kit as preventative maintenance. Go figure- try to avoid problems and caused one while doing so! The water pipe caught the edge of the bushing folding over/ cutting it. Of course there was none available in the immediate area and it would have been a few days for a $3 part. We glued it carefully and I'm back in the water no issues. I'll replace the bushing after she's hauled out after the season.

[Moonlighter]

Thanks for asking Freddy. When we dropped the lower unit it was very apparent that the water pump case bushing that sits directly on top of the pump was damaged. It got damaged when we were struggling to line the splines up with a little back and forth in the off season after replacing the impeller kit as preventative maintenance. Go figure- try to avoid problems and caused one while doing so! The water pipe caught the edge of the bushing folding over/ cutting it. Of course there was none available in the immediate area and it would have been a few days for a $3 part. We glued it carefully and I'm back in the water no issues. I'll replace the bushing after she's hauled out after the season.

Thanks for the update.

Its really helpful to members if people report back when their issues are resolved and outline what the solution was.