overheating

[caseycody]

I have a kohler 5e that is shutting down after about 20 mins. with a temp reading of 253 on radiator cap and 170 on heatexchanger .exhaust reads 70 with water coming out looks like a good stream but can't figure out
the overheating. oil level correct , antifreeze ok, getting spark
please help

[billknny]

Have you checked the thermostat? If no, do so. If yes, please list all the other things you have tried to fix the problem so we can avoid making suggestions over and over only to have you reply that you tried that.

[Sailmonkey]

Have you ever clean d the heat exchanger?

[caseycody]

I have a new thermostate, new fuel pump, havent' clean heat exchanger yet or try removing bleed screw to see if it might have air bubble

[caseycody]

no i was going to do that, can you use same o ring
temp went to 253 on radiator cap 170 on heat exchanger exhause showed 70 degrees of water coming out. used a laser thermometer getting spark but couldn't get to other plug to check, is it located in back of gen front easy to get too
what should temp run on radiator cap and heat exchanger

[Sailmonkey]

180-200 is my best guess for the radiator cap.

If you’ve got cool water in, cool water out, it sounds like your tube bundle is due for a cleaning.

Pull it out, and soak it in clr for a short while until it’s de-scaled and no longer fizzy.

[caseycody]

sailmonkey are you talking about the heat exchanger? when talking about bundle tube

[jkishel]

Fresh water is hot while seawater is cool. Therefore, insufficient heat transfer is occurring from the fresh water circuit to the sea water circuit. Possible causes include inadequate fresh water coolant level, bad fresh water pump (no or inadequate circulation), bad thermostat and scaled heat exchanger.

[Sailmonkey]

Originally Posted by caseycody

sailmonkey are you talking about the heat exchanger? when talking about bundle tube

Yep. You may need to remove the entire housing from the engine to have a chance at cleaning it.

[kenbo]

All good suggestions above. But if you just put in new tstat you may simoly have an air lock in the fresh water cooling loop. Try bleeding.

[caseycody]

Going down Sunday, starting with hoses to see if obstructed, then heat exchanger, and last but not least bleed it. Wish me luck will let you know how it comes out and many thanks to you all

[caseycody]

will head gasket cause over heating

[a64pilot]

Originally Posted by caseycody

will head gasket cause over heating

Yes, if the engine is losing water, or if the head gasket is not the correct one or is installed incorrectly.

[billknny]

I'd bleed the cooling circuit first. It's the easiest of the fixes on your list.

One thing that is not clear in the narrative so far, did you do any maintenance on the engine BEFORE the overheating problem started?

[caseycody]

Billknny, yes replaced auto chock, thermo, impeller