5.7 engine ALARM- safe mode

[Davicsta@hotmail.com]

Mercruiser 5.7 Gi-G..safe mode- alarm

going into 2nd season being frustrated. after 2-3’ running just over 3000 rpm & 25mph. Intermittent alarm sounds and send the boat into Safe Mode & 90% loss of power. Have to disconnect alarm for a Minute, then hook back up & do it all over again. Running nearly 200 degrees. I have changed impeller, t-stat, temperature sensor on t-stat housing. Hooking up this weekend to get codes read by mechanic. Any ideas?

 

[alldodge]

If your running near 200* then you may be even hotter or the sensor is telling the ECM it is.

Use an IR temp gun and measure the temp of the thermostat housing

Your motor will have a temp sensor which is used to show temp on the gauge, but also has a temp switch that tells the ECM its to hot