HELP Needed - overheating engine Part 2..

[RobertMartin]

Thankyou for all the helpful responses, One thing I forgot to mention (opps ).. The engine had a full rebuild 3 months ago, The shipwright says it worked fine when he tested it. I did not use it for a 6 weeks after that, and have only used it twice since then!! He seemed to be scratching his head a lot when he was looking at it last night, I do not think he checked the exhast. I will do that tonight. When i got the boat he found the divert from the engine to the hotwater was blocked off, ( maybe they had a problem too ). I guess I need to do a diesel course... I love sailing, but as for engines......
Note - please god, send us the fuel cell and electric propulsion...

Bobby aka Seawolf..
Sail as if your free

 

[johnt]

try flushing the cooling system with brick cleaner

put it in,let it vent,but kee it topped up
empty after a couple of hours and flush well with fresh water

 

[jfkal]

Welcomed to the club. The previous owner of my boat paid 1500 Pounds for a complete overhaul. After it was done: Engine leaks oil, injectors are not working properly, Injection pump has problems and the headgasket lets water into the engine. I did it up myself then (speed learning about diesels by doing) now everything is fine. You might still have a blockage somewhere. Might not have shown up during bench-testing (no load and too short time).

AND YES I am waiting for fuel cells myself. But I am afraid that we will have to wait another 10 or more years. All the diesel engine makers do their best not to see this happening anytime soon.

KEEP THE DIESELS COUGHIN' AND BELCHIN'

 

[Avocet]

Haven't read the first part yet, but has someone suggested taking the thermostat out and trying it? My rew water cooled BMW D12 overheats initially untill you tap the thermostat housing with a hammer (or winch handle) a few times. It then opens with a jolt and the temperature drops. I'll have to replace it this winter.

 

[oldharry]

The problem is almost certainly due to blocked waterways somewhere in the engine.

Unless the mechanic was specifically looking for causes of overheating it is likely he will not have spotted partial blocking in the bloack and head waterways.

If a heat exchanger is fitted are all the tubes clear. An exchanger with as much as 80% of tubes blocked will still pass a copious flow of water and appear to be OK, but have nothing like enough contact area still functioning to transfer the heat to the seawater.

Also suspect a rebuild problem: incorrectly set timing or cam timing would result in power loss, but a head gasket put on upside down could reduce or stop coolant reaching the head, as it would if the wrong gasket has been fitted. Its not always by any means clear which way up a head gasket should be fitted to the engine, but the end result can be reduced coolant flow to key parts of the engine.