mattonthesea
Well-Known Member
Last checked about 400 hours ago. I've been religiously running at above 2800 rpm every hour to clear the elbow
MD2030 using water.
- Thread starter MM5AHO
- Start date
MM5AHO
Well-Known Member
My update. New rubber boots, exhaust elbow cleaned out. Engine has about 200 hours since being out for rebuild. (2 summers). Tube bundle pressure tested. One old boot found leaking. Both changed. Still losing water. Mystery. Not head gasket.
mickbond
Well-Known Member
MM5AHO If it's not going out of the exhaust ot leaking anywhere, I don't know where it can be going. How hot does the engine run. Mine stays at 70C measured with IR thermometer on the heat exchanger?
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mattonthesea
Well-Known Member
Pressure tested the system; it's a hole in a hosepipe directly behind alternator. Couldn't see because spray was directed away
Phew. Still plan to check elbow etc later when at leisure
Phew. Still plan to check elbow etc later when at leisure
MM5AHO
Well-Known Member
Further update. I now suspect the cooling water pump (now seawater pump), or thermostat. There's steam coming from the pressure cap overflow hose. Steam not accumulating in bilge, but evaporating. Also calorifier taking a long time to heat water, also suggesting lack of coolant flow. Aim to remove pump and inspect this winter. Might be thermostat not opening? Or pump not circulating?
Tamar
Well-Known Member
Are you certain it's not the head gasket?
MM5AHO
Well-Known Member
No, I'm not certain. Fuel economy is normal. No steam in exhaust, no water in the lube oil. Any other checks I could do to be "certain" ?
Tamar
Well-Known Member
I just commented because I have the same engine with the same problem. No symptoms except the engine pushing out the coolant. I changed everything I could as I had a new gasket fitted last year and I was sure it wasn't that. But before I spent anymore money on it I took the head off just to check and sure enough a tiny blow by. New gasket has sorted it.
There is a product you can put into the cooling system that will show you if the gasket has blown, I am unable to post a link but a Google search will find it. Good luck.
Openelectron
New Member
I have the same engine and the same problem this summer.
We were taking the boat through the crinan canal. All of a sudden the overheat alarm went off and the engine stopped. We managed to get tied up.
I took it apart and there was a hole corroded through, we had lots all coolant. New part not available, second hand part a week away.
I went and got some epoxy and patches the hole, jammed a cable tie in the radiator cap spring and ran the expansion pipe up the side of the door frame making a steam engine style sight glass.
Then I plumbed in our cold water feed through a valve to the engine at the calorifier so I could keep topping it up. 2 days trip back, lots of stress!
We were taking the boat through the crinan canal. All of a sudden the overheat alarm went off and the engine stopped. We managed to get tied up.
I took it apart and there was a hole corroded through, we had lots all coolant. New part not available, second hand part a week away.
I went and got some epoxy and patches the hole, jammed a cable tie in the radiator cap spring and ran the expansion pipe up the side of the door frame making a steam engine style sight glass.
Then I plumbed in our cold water feed through a valve to the engine at the calorifier so I could keep topping it up. 2 days trip back, lots of stress!
