running a little warm

[frosh coach]

I have a 94 30’ Sea Ray Sundancer with Twin 350/260 Mercruiser FWC Alpha’s. Last season I noticed the port engine was running around 170°F in August. The starboard runs about 160°F. Fast forward to this season. When I launched in Mid-May they both run at around 160°F. This past weekend I noticed the starboard at 170°f again.

Any Ideas? Could this be due to the water warming up? I’m thinking about changing the impellers on the circ pumps. I’m not sure when the risers and manifolds were done last. I’m hoping to get through the rest of this season and change them at the beginning of next season.
Thanks
Chris

 

[CliffA]

I have a 94 30’ Sea Ray Sundancer with Twin 350/260 Mercruiser FWC Alpha’s. Last season I noticed the port engine was running around 170°F in August. The starboard runs about 160°F. Fast forward to this season. When I launched in Mid-May they both run at around 160°F. This past weekend I noticed the starboard at 170°f again.

Any Ideas? Could this be due to the water warming up? I’m thinking about changing the impellers on the circ pumps. I’m not sure when the risers and manifolds were done last. I’m hoping to get through the rest of this season and change them at the beginning of next season.
Thanks
Chris

you could swap a couple parts around between engines to see if the higher temp follows...maybe start with swapping thermostats since that is an easy swap....if that does not show anything then maybe swap the temp senders.....if the higher temp switches from engine to engine after one of these swaps you need to replace that part on the engine with the higher temp.....

cliff

 

[Lazy Daze]

I'd start by verifying that you are, indeed, having warmer temps - especially before purchasing anything. Could be a gauge, could be a sender -- might not be, but best to eliminate this variable, first. Check the temps (IR gun is great, but your hand will also work) at the exact same spots on both engines - spots like top of t-stat housing, where the temp sender screws in, even the top of the exhaust elbows. In other words, let's see if there's an actual "physical" problem, or is it just a "read-out"/gauge problem. Then you can go on to swapping like Cliff mentioned (or just simply R&R something like the stat) before moving on to more expensive stuff.

FYI, there's no rubber "impeller" like you're thinking on the circ pump - you'll change the whole thing.

 

[dicor]

I don't want to be an alarmist an go straight to the high dollar item but I will anyhow. If it turns out to be your manifold/risers and they begin to send water to the block you are talking big $$$$$ if the engine hydra-locks. Over heating or no overheating I would replace them only because I don't when or if they have ever been replaced and you are most definitely running in salt water.

 

[frosh coach]

Thanks all for the info...
Dicor - yes i'm in salt water.
Dave - I'll check with a gun and by hand.

FUnny thin is it did the same thing last year at the same time.... but was cool this for most of this season. I should add this is also when im crusing... when I slow down (dock or no wake speed they both stay around 160/165)