Engine temp question

[renestor]

Hello all, hope someone can help me, I have a 1990 350 sea ray EC with 454 mercs, raw water cooled, are my engine temps ok??, I am attaching pics of my port and starboard engines, running at 2500 rpm. The boat have been running great for almost 90 hours at those temps, since I bought her last year, but I am bit worried, that maybe its running a bit hot, Should I replace my impellers?? Any other recommendation?? thanks

Port engine
https://www.dropbox.com/s/21zq5wsczh5xdq8/2013-12-22 15.25.52.jpg

Starboard engine
https://www.dropbox.com/s/u3mwe8f19ztwh7m/2013-12-22 15.26.14.jpg

 

[Joe5.0]

If the gauage is 100% accurate (which is a little suspect in a 25 year old setup), its runng ~ 180-185*, which is at the upper end of operating temperature. What was the ambient temp?

If its running good and not going above 200* I wouldnt worry, but if the impellers are more than a 2-3 seasons old it's probably a good idea to replace anyways.

 

[MExcelsior]

I would definitely change the impellers! I would also recommend changing out the thermostats as a matter of personal maintenance/knowing since this boat is new-to-you within the last year. (This is optional, and less critical). These are relatively inexpensive items (especially if you change out yourself), that tend to create a very very big expense if they fail.

Good luck,
Mike

 

[mquiet]

shoot the risers with a temp gun and verify that the temp is the same on all 4 sides. Repeat on all risers. It will be cooler than your gauge, but will give you an idea if the engines are running the same relative temperatures. I also agree with above and change impellers and gauges as well(reassurance).

 

[dpmulvey]

shoot the risers with a temp gun and verify that the temp is the same on all 4 sides. Repeat on all risers. It will be cooler than your gauge, but will give you an idea if the engines are running the same relative temperatures. I also agree with above and change impellers and gauges as well(reassurance).

DING!!! DING!!!DING!!!

We we have a winner!

 

[Joe5.0]

Wouldnt the best way to see if they're accurate is an IR reading off the thermostat housing or intake manifold right next to the thermostat? The exhaust manifolds should be significantly hotter than what the temp gauge is reading, since the raw water just passed the combustion chamber.....

 

[rondds]

The sender is in the thermostat housing. That's where you shoot for comparison. Exhaust elbows should be around 90-100* - not scalding to the touch (with the engines running). They will heat up when you shut the engine down so don't do any of these "tests" unless they are running at operating temperature.

 

[renestor]

thanks for all your answers, definetly I will change the impellers, and ask my mechanic to check the status of the thermostats. I need to have everthing ok, because we are starting our summer season, so the boat will be used every weekend.

 

[Shock_Loaded]

DING!!! DING!!!DING!!!

We we have a winner!

Battled the same temps as you and higher if I ran up on plane at 3250-3400rpm. Verified temp gauges were correct, they were very close. PO had replaced senders. Replaced impellers and t stats, did absolutely nothing to temps; the old ones looked pretty good. Pulled manifolds and risers, they were all full of rust. Replaced manifolds and risers, and voila! temps running rock steady at 150 up on plane.
Pull all the plugs from the manifolds and risers, my bet is they are full of rust. Good luck!!

 

[Shock_Loaded]

Oh, if you have heat exchangers, this will be a good time to pull the end plates, pressure check and rod all the tubes. You will have the antifreeze out and its a quick check to make sure all is well with them especially if they are original as they are getting up in years like mine.
Now get to work so you can enjoy your summer!

 

[rondds]

The long standing "running hot" problem with my 340DB's port engine turned out to be the heat exchanger. Previous owner changed the gauge, I replace the sender, the thermostat, the impeller. No change. I pulled the end caps and stuck a wire into every single tube and shined a light through each one. All seemed fine. Finally took the whole thing off and brought it to a radiator shop for a pressure test and boil out. He replace a tube or two and re-sprayed it for about $175 and that was the ticket to worry-free boating. Worth every penny and the mess of dumped coolant!

 

[renestor]

Thanks for all your answers, about the heat exchanger, I dont think my boat has one, it is raw water cooled.

Also, cansomeone recommend a good online store were I can buy engine parts, like impellers, risers, etc

thanks