Originally Posted by Juggles
Hey guys. My god not sure what makes me want to cry more. The engine or trying to reply on here via mobile. I've been trying to reply for a couple days but on mobile the page just dies. Sorry for radio
We have raw water and coolant. Water and oil level are fine. Strainer is empty. Someone at the club said we may have the wrong oil. We have penrite marine 4 stroke
. He just said it's not right. Not sure. Guy was drunk. Either way my partners gone to buy some 15 40 oil even though the penrite says it can be used in place of 15 40.
Seacock was open but I do wonder if he opened it fully as it's hidden behind a bunch of junk. There is water coming from the exhaust. I'll take a small video tomorrow.
I'll be back on the boat tomorrow. I'll trace all the hoses and get some photos then. I also agree about the corrugated hose. I thought that was bilge
hose not cooling hose. What would you change it to?
As for the intake. Is there a way to clean that while on the boat?
Good to here back from you.
As long as the level is correct, the oil should make no difference at all.
That water is pumped out the exhaust is good; the important thing is how much, relevant to engine speed. 2-4 gallons per minute for a small diesel
engine at cruise
would be an educated guess as a starting point.
Some quantification of 'overheat' would be good, especially given the no-reference starting point of 'instruments off'. What does the gauge read when 'overheated' now? It is common for electrically-operated gauges to give inaccurate information; the heat gun idea is good, but you can also tell a lot just by touch. A good hot engine can be touched for a second without burning you, but if you're afraid to touch it, something is likely wrong. If smoke is coming from painted surfaces (not out the exhaust), something is definitely wrong.
Some more---comprehensive?---pictures will help. If you can move back from the objective so that we can see a more complete picture, we may be able to spot problems that are not evident to a newcomer
It's hard to check the intake completely from inside the boat. That you're getting water from the exhaust now is encouraging. A simple test, if the design of the strainer allows it, would be to open it as if you were going to clean it, with the seacock open, and note the flow. If the flow is good, then the intake is likely clear. This, of course, says nothing about the flow downstream from the strainer...
By corrugated hose, I assume you mean wire-reinforced hose. It is common enough to see its use on the suction side of raw water systems; the thought seems to be that it will keep the hose from collapsing from the suction of the raw water pump
, which it will. But the system should be free-flowing, and the use of wire-reinforced hose is often not necessary on the suction side of small engine installations.
There are only two 'corrugated' hoses, that I can see. The black one to the left in the second picture, which, if it is the supply for the raw water pump
, would be a proper application, and the blue, large diameter 'hose' in the third picture, which, though hard to be sure, looks like a vent or air duct, another proper application.
There seems to be a little confusion about engine cooling systems, so perhaps some clarification is in order.
There are several different ways to water cool an engine, but the two most common for small boat
engines are generally known as 'freshwater cooling' (or 'closed-loop') and 'raw water cooling'.
Both systems have a raw water pump
; the difference is that in the freshwater system, the raw water is pumped through a heat exchanger, which contains freshwater (or 'coolant', usually a mixture of water and antifreeze/anti-boil/conditioner), which is itself pumped through the engine (by a separate freshwater 'circulation' pump) in a closed loop that transfers the heat generated by the engine to the raw water pumped through the heat exchanger, which isolates the majority of (expensive) engine components from the deleterious effects of sea water.
In a raw water cooled system, seawater ('raw' water) itself is used to cool all internal parts
of the engine, sometimes in conjunction with a circulation pump, sometimes without. This brings with it special conditions that can and have been met by certain adaptations which can provide servicable life for most components, but generally speaking, life expectancy is shorter than with the freshwater-cooled engines.