engine overheated-barnacles

[g.spier]

I had problem last weekend with engine overheated. Thought the worst, water pump impeller or something else. Dove down to find that barnacles had grown inside my water intake had to use a putty knife to remove. Barnacle had covered the propeller. Question has anyone used outdrive paint on their prop??
Barnacles had engulfed the bow thruster and I thought my shear pin had broken. So after one tank of air everything is wonderful again with my boat.
Cummins diesel water temp should be between 180-200 degrees????
Water has been very warm in R.I.

[JackK]

Yes, mine runs right at 180 degrees.

Jack

[Tuxedo]

Temp seems high, especially 200 degrees. My 450C ran at 175 degrees in 85 degree water (how's that for warm water?).

Some questions -
What's the setting of the thermostat?
When was the heat exchanger last cleaned?

Also, you are changing your zincs, right?

[muscrat]

I have a Cummins in my 96 and it runs aournd 185- 190 consistently. I am pretty sure the thermostats start to open @ 185 but they are not fully open until 195..

[Pitou]

After an impellar change my Cummins 370 Turbo runs at 180 degrees and begins to creep towards the end of the second season to 185 ish and begining of 3rd season to 190. Time for an impellar service???

[muscrat]

pitou,

I change mine every year, they are not worn out at that time. I am more concerned with the material degrading. Seaboard Marine has a new impeller that appears to be an improvement to the stock brand and when I use up my spares I may buy one to try it..

Steve

[Merry Kate]

Pitou -

190 is OK for a Cummins 6B, but temperature creep over several seasons means your raw water side is getting less than perfect. Try a new impeller first. I usually change mine yearly, but sometimes go 2 seasons. If it does'nt get you back down to 185 a heat exchager flush with Rydlime does wonders.

[jcollins]

Pitou -

190 is OK for a Cummins 6B, but temperature creep over several seasons means your raw water side is getting less than perfect. Try a new impeller first. I usually change mine yearly, but sometimes go 2 seasons. If it does'nt get you back down to 185 a heat exchager flush with Rydlime does wonders.

Exchanger flush? Is that DIY project?

[StockHR]

Our 6B runs about 185 @ 2200 RPMs. John I understand that there is a marina off the Patapsco River (Baltimore) that charges only $4.00 a foot for a haul and bottom pressure wash. Mike

[StockHR]

Found this link. Seems like a good product to use but really have to follow the directions. Mike
http://www.rydlymemarine.com/instructions.html

[jleonard]

For you guys running 5 to 10 degrees warmer than before....
Carefully check your water strainer lid to make sure it is sealed. Use grease on the threads and that will insure a positive seal.
You may be losing just a little flow because of this and that will make the temp creep up....A friend of mine had this issue on a Cummins 270 (in an older Mainship) and this was the simple solution....after almost 1 year of chasing a ghost.
Hope this helps.
Jay

[Merry Kate]

John - Very much a DIY project. There was a thread a few back that shows the setup I used:

viewtopic.php?t=892

Like I said, the most trouble was piecing together fittings that adapted to the heat-x hoses.