Trek said..UncleBob said..Trek said..The conclusion .... Grich you were right to be suspicious about the lack of coolant in the water, and your magnet idea Sam, I should have tried that, the black stuff is cast iron fragments.
Sandy went out to the boat today with a magnet and thats what he found. Motor is fine, just needs flushing and put in coolant! Recommendations for what kind of coolant would be welcome.
I think I would want to know where the iron fragments came from! Fresh water pump perhaps?
Cheers Bob.
Agreed Bob.
I believe they have come from the walls of the cooling system in its entirety. ie. The cooling system consists of holes bored through a cast iron block and the walls of those holes have oxidized. Previously I put a filter in line with the water and each time I flushed the cooling system with fresh water less was captured by the filter.
After we've flushed the motor a few times and put the right additives in we'll see if it comes back. Grich if you are around what additives do you suggest?
volvo coolant is the best for this eng ,it will have glycol and a inhibitor.glycol is for the anti freeze,anti boil and the inhibitor is for the corrosion control,it is very important that the inhibitor is kept at its correct level ,you normally buy test strips to keep an eye on it and top it up. fleetgaurd also make a good product available as a premix at most truck places.castrol sell glycol in concentrate which you can mix 50/50 with water then add a inhibitor.dont use car coolants as they are for alloy engs, most eng makes sell a cleaning agent to clean out the block,great to hear the eng is ok .
greg
