Volvo MD2030 dumping coolant

[tuffyluffy 76]

49 minutes ago, Dtwo said:

Where are you?  I've got some on the boat - currently Mahurangi

Many thanks for the offer, but I'm at Piha, the part is in my shed and the boat is at Hobsonville

[harrytom 679]

Boil the crap out of it ,while hot use like a wire tooth brush.

[tuffyluffy 76]

Thanks all for the offers of acid! Luckily my neighbour had some so i used that over weekend and it did a great job.

The offending part was soaked overnight and came up a treat. Its now installed and the problem seems to be resolved 👍

 

[m500sad 0]

On 17/02/2020 at 7:19 PM, tuffyluffy said:

Many thanks everyone for the input - much appreciated!

 

It sound like a methodical approach starting at the cap, impeller, then check and clean the heat exchanger, check thermostat and then exhaust mixer will be the plan - fingers crossed. 

 

As an FYI, the engine was rebuilt less than 100 hours ago but has had very little over the past few years hence I'm pretty comfortable its not a head gasket, also, the water in the heat exchanger is perfectly clean, but we will see. . . . 

 

Lets hope i havent killed the engine for the second time 

 

Thanks again, I'll report back once i find some time to get into it

Its the exhaust elbow sea water passage way getting blocked. The seawater pump pumps, it cant get out of the system into the elbow fast enough, the sea water passes from the seawater side to the fresh water side past the hose clamps and pressureizes the fresh water sytem and it dumps through the over flow. The symptom that the exhaust water  flow is diminished confirms this. 

Take the elbow off and clean the seawater passages. Be careful, it will break easily. I take the tube bundle out and the elbow off. I assemble the tube bundle and end caps, connect the elbow to it and put a hose pipe with a good pressure on to the inlet. if the elbow is restrictedyou can see the water passing the clips and usually it blows one of the caps off.