year 2000 Merc 200hp running hot

[Brian Robertson]

This is a new engine to me - the temp gauge says it is running hot - no alarm sounds - water pump is new and working - one mechanic says it is probably the gauge - also could be sender switch or thermostat - It appears there is a thermostat and sender switch in each head - not sure? Would these be the thermostats that control water flow or just something to do with sender switch? Is there any way to determine which part may be causing the problem or which part to change out first?

 

[NathanY]

Re: year 2000 Merc 200hp running hot

Have you put a thermometer on the engine to see if it is running hot? Have you felt the engine? If it is truly not running hot, I would replace the sensors on the motor and/or the guage.

 

[Kenny Bush]

Re: year 2000 Merc 200hp running hot

Brian, as Nathan said, get a temperature reading on the head after engine is warmed up....If<br />you do not have one, warm the engine up and touch the heads and block with your fingers... Normal range will only let you touch it for a couple of seconds.....if it is hot, you will not be able to touch hardly at all.....Good luck...BushCat