Mercruiser 5.0 runs consistently at 180 F

[eddieshack23]

I just launched my 2002 SeaRay for the season. It has a 5.0 L Mercruiser with an Alpha one Drive and it is running at 180 degrees F consistently. It doesn't climb any higher than that and only went back down to 160 once as I was idling. Otherwise it sat at 180. The boat was winterized by the dealer and only has 30 hours on the engine and drive in total. I am not sure what thermostat it has in it, but 180 is slightly above the "normal" range on my temp gauge. Is this something I should be concerned about? Are there any basic checks I should run before I pull the boat and take it to a shop?

 

[FreeBeeTony]

Re: Mercruiser 5.0 runs consistently at 180 F

Is it raw water cooled or FWC? 180* sounds high for raw water cooled. If it's FWC I wouldn't worry about it.

 

[crazy charlie]

Re: Mercruiser 5.0 runs consistently at 180 F

The consistency of the temp is a good thing and as Tony said if it is raw water cooled it is high and you should check at least the impeller.Charlie

 

[paul64]

Re: Mercruiser 5.0 runs consistently at 180 F

I have a 5.0L VP, raw water cooled..it is only a couple of months old, and has run @180 since new..I asked the same question on this forum, and with my dealer, and the consistency is definitely the key..one suggestion was to look at the temp gauge, as it may be reading wrong...

 

[crazy charlie]

Re: Mercruiser 5.0 runs consistently at 180 F

The big concern I would have is that RWC mercs are 145 degree motors.Thats where they are supposed to run.The reason they are supposed to run there is because somewhere around 190 degrees or more the salt in salt water crystalizes. 180 is pretty close to that mark.I would not feel comfortable in salt water if mine were running over 155-160 degrees.Charlie