Mercruiser 3.0L Warmer Than Normal

[Viking62]

I have a 2008 3.0l with an Alpha 1 drive. It has a 160* thermostat. The temp gauge (Faria) has always run around 175*. This year since I put it in it is now running closer to 200* on the gauge. I have used an infared temp. gun around the engine and the highest temp I can find is around 155* near the temp sensor.
I pulled the sensor and checked resistance vs temp as per the Mercruiser manual and it seems to be ok. I have changed the thermostat, the impeller in the drive and checked the hoses for obstructions. All check ok even the impeller didn't show any signs of wear but I replaced it anyway. Still runs warmer than normal according to the gauge.
At this point I don't know if I have a problem or not.
Any ideas or input? Could it be a bad gauge and if so how would I test it?
Thanks, Mike

 

[Don S]

Re: Mercruiser 3.0L Warmer Than Normal

If the engine is actually running cool per the temp gun, and you can actually touch it and hold your hand on if for 5 seconds, the engine is not overheating. If the sender is ok, then it only leaves the gauge itself as being the problem. Replace it.

 

[Viking62]

Re: Mercruiser 3.0L Warmer Than Normal

Wow that was quick. I was concerned I wasn't getting an accurate reading with my temp gun but I can't get close to 200* anywhere. I can hold all the hoses with my hand and the exhaust riser isn't hot. Thanks for the quick response. I'll try to find a faria dealer locally.