200 e-tec overheat

[towhorse]

My 200 E-Tec H.O. E200DHXSC #5214893 started running hot last week, but only occasionally. The HOT light would come on, but the gauge still showed 140. I would shut her off, turn it on again, problem went away, gauge would drop even more on plane, for a week. Now its back and its hot on the gauge and the light. Won't even get out of the marina and she's hot.
Hooked up the laptop, while idling, the Strb. bank climbs up to 90 Celcius in 5 minutes or so, Port bank stays around 85 degrees. (gotta figure out how to set it to Fahrenheit to match the dash gauges). EMM temp stays around 60.C.
330 hrs, so I replace the impellers on both motors. They looked good and clean. Blew out the cooling lines to EMM and fuel canister, nothing in them. Cleaned out the T-stats, and by-pass, no dirt to be found.
Put it back in the water, no change.
Pull the lower unit off again, stuck a hose down the T-stat holes to flush the gremlin out, put a bucket under the engine to catch the little rat, nothing yet. Little bit of brown slime, if that. Replaced the impeller plate, gasket and seals and bolted the pump back together real carefully again tonight, left some D-Con under the cowling to get whatever is messing with my motor. Any thoughts, suggestions?

Walter

[kisskollector]

Is it peeing water out fine ? Maybe the temperature sensor is not working???

[ChampioNman]

Default operation is metric, go to utilities then program configuration then check the English box. You will now show English units.

[SEAHORSE]

When the HOT LIGHT came on, did the motor automatically go to about 1200 rpm? If not, you were just getting a warning.

Because the temp sensor and the overheat sensor read differently, it would be a good idea to check both items for accuracy.

Also see you dealer to make sure your motor's temp sensors have been packed with heat sink compound per service bulletin 2008-01(S)

[towhorse]

Yes, the motor went into SAFE mode and the sensors all have this brown gasket cement around them. The software clearly shows the temps climbing on both sides and the EMM temp till she beeps on the dashboard. The accessory temp gauge has then also climbed up to 180 and higher.
The water pump was rebuilt twice now, new thermostats did nothing. I put in the old T-stats, but ripped out their guts to create better flow at all times. That helped, now I can run all day, but have to hurry to get to my slip before the temp climbs up. Which seems to suggest a bad water pump, but I shoved a garden hose up the water tube with street pressure and the problem is there too. How about melted or plugged water dams inside the head?
I think its time to load the boat up and go find a dealer.....

[SEAHORSE]

You or your dealer may have to troubleshoot the problem with the temporary installation of a water pressure gauge. There are charts that state what the minimum water pressure should be at different rpms. Your dealer should be aware of them or he can call the factory-dealer hot-line for technical help.

One common problem is an incorrectly clamped overboard water hose at the rear of the adapter plate. Sometimes the boat hull design, strakes, transducers, thru-hull fittings, trim tabs, etc. can disrupt the water flow to the motor at certain speeds.

Sometimes in exceptional circumstances, a 7# pressure relief spring and plunger may be substituted for the 10# spring.