Kohler EC62 Low Seawater Pump Pressure

rmrstlmo

I have a Kohler 7.3 genset that shut down over the weekend with a EC62 code.  The exhaust water flow is probably 10% of what it normally is.  It will start and run for about 10 seconds then shut down and get the same error code. These are the things I've tried and still get the same result:

  The strainer had a small amount of debris - cleaned it and no better. 
  The impeller seemed to be the next obvious fix so I replaced it.  The one that I removed have a couple of small cracks but no missing pieces.
   I checked water flow on the output side of the pump and it seems reasonable but I don't have any real experience to know if it is correct. 
  Also checked water flow on the output side of the heat exchanger and it also seemed reasonable.
  Used a brush to clean the seacock intake and blew air through the seacock from inside the boat.
 
I used a garden hose to supply water from the hose that attaches to the seacock.  It ran fine for about a minute and then I shut it down with no error code.  Reattached the seacock hose and still get the same error code and small amount of water flow out the exhaust.

What else should I check?  Thanks in advance!

aero3113

You could need a new water pressure switch. Also, behind the impeller is a coupler. It’s possible that needs to be replaced. Here’s some pictures for reference.

rmrstlmo

I took off the plate behind the impeller.  The coupler looked fine.  (Should have put that in the original post.) 

Could the water pressure switch reduce the amount of water coming out the exhaust?

aero3113

Disconnect the wires from the switch and see if it will run. If it does run, your switch is bad.

Formulaben

I'm guessing the problem is water pressure.  I'll put a beer on it that either your face seal or rear seal on the impeller pump is letting air in and it's losing pressure. 

Dream_Inn

Formulaben said:

I'm guessing the problem is water pressure.  I'll put a beer on it that either your face seal or rear seal on the impeller pump is letting air in and it's losing pressure. 

If it’s letting air in, it is usually leaking water.  How about the anti siphon?

rmrstlmo

@Dream_Inn are you suggesting the the anti siphon is leaking air while the gen is running?  That should be easy to check.  I'll be at the boat to try the suggestions posted and will report back.

Dream_Inn

rmrstlmo said:

@Dream_Inn are you suggesting the the anti siphon is leaking air while the gen is running?  That should be easy to check.  I'll be at the boat to try the suggestions posted and will report back.

Yes, definitely a possibility and easy to check.

rmrstlmo

Got to the boat late yesterday.  Went to inspect the anti siphon valve and the cap was loose.  Pulled it out to look to check it and it looked perfect.  Put it back on with hand tight.  Genny fired up and ran for over an hour with no issues!  Another issued solved from this forum. Thanks to all and especially @Dream_Inn!

Dream_Inn

that is great @rmrstlmo !  It’s nice when it’s an easy fix!

aero3113

Awesome!! ⚓️

raybo3

Awesome