Originally Posted by Opie91
Does all the coolant look like that? or just in the overflow tank after you serviced it? 3 years/300 hours without a zinc is a long time.
The fresh water cooling system heat exchanger may have broken down resulting in sea water mixing with your engine coolant. (Brown, opaque and sludgy)
The best way to check this is with a cooling system pressure tester:
Amazon.com: Stant 12270 30 Pound Cooling System And Pressure Cap Tester: Automotive
If your are in a shipyard one of the engineers/mechanics might be able to loan you one.
If you do not have/cant find a pressure tester, you might be able to find out if it is total shot by doing a quick check:
- First close the raw water intake thru hull for the gen set.
- Pull the zinc out of the heat exchanger and let it drain completely.
- Then remove the coolant cap and see if the coolant goes down. Give it a while and see if anything else comes out of the heat exchanger zinc hole. If the fresh water coolant level drops the the heat exchanger is most likely shot and the engine is full of salt water.
This is by no means a full check out of your cooling system, but it may point you in the right direction.
Hopefully its is just ugly coolant. Good Luck
So, this little problem -- seaweed in the seawater intake -- has spiralled into a major generator
breakdown, it seems.
Yesterday I struggled with the salt
water side of the cooling system -- couldn't solve a problem with the seawater pump heating
up. There is a separate thread on it here: Baffling, Maddening Impeller Problem
This morning I got up to find that the fresh water side of the cooling system is dry. So -- it means the fresh water cooling system is breached somewhere.
It was so upsetting when it seemed that I just needed a flush and new coolant, and couldn't get the genset working again. Now after a good night's sleep I'm just resigned to having another project
-- so one foot after the other, work it out and solve it. An unexpected and unwelcome project
, but what the h*ll -- it's cruising, ain't it?
I guess the exhaust
manifold is cracked because I did observe a little bit of fizzing in the coolant fill neck.
On the other hand, I have this bizarre raw water side problem, with the seawater pump heating
up (Baffling, Maddening Impeller Problem
). So MAYBE -- it's the heat exchanger, which is the one place where salt
and fresh come together -- maybe it's collapsed and obstructing the flow of seawater, and at the same time causing the breach of the fresh water wide. What do y'all think?
I'm at anchor
off Yarmouth; I'm going to head
into Poole and tie up to a dock
and pull out the heat exchanger -- which I need to do in any case according to the principle of "eliminate the simpler things first". The heat exchanger is relatively easy to get to, being separate from the engine block (unlike on my main engine). It is like a pipe with end caps which come off, so I should be able to take it apart and check it out.
If the heat exchanger seems to be o.k., then I'll clean it out, get a proper impeller, and try it again (with little hope, but need to check).
That must solve my sea water side problem at least, unless someone has some other idea about it.
If I continue to loose coolant from the fresh water side, then I'll pull off the exhaust
manifold and blow through it. If I don't find a crack like that, then I guess I'll have to have it magnafluxed.
Do you all agree with my proposed diagnostic sequence here?
I have high hopes that the worst that it could be is the exhaust manifold, and that we cannot be talking about a cracked head
or block here. That's because there is no oil
in the coolant, no coolant in the oil
, and the engine starts and runs perfectly.
So of course the whole story is a big disappointment -- I had a long list of other things I wanted to fix on the boat before my big trip a month from now -- and the Kohler generator was the last thing in the world I expected to give me major trouble. But s**t happens, doesn't it. Not the end of the world. I guess it won't bankrupt me to buy a new heat exchanger and/or exhaust manifold for it.