Originally Posted by rlg
when I fill with coolant
, some does leak out cap after engine
is warm, then it stops. I may not be losing any coolant
From my experience, the last thing I worked on is usually the problem. I just cant figure how the exhaust
maniflold/coolant "tank" is causing the problem, maybe its not
Coolant gets hot so it expands and overflows a little. If you look at a coolant recovery tank on a car for instance, you will see a hot and cold mark on the tank. If you overfill above the mark, you will loose coolant on a car. Same for a boat. Overfill the coolant tank and you will loose coolant for sure.
If you are getting normal flow of raw water
out the exhaust
, the only think I can think of is the heat exchanger
has a lot of scale, but then the temperature gauge would be high. If the thermostat is stuck in a slightly open position restricting flow on the engine
side, then the temperature gauge would also show higher than normal temperature.
If there is a crack in the head
from combustion changer to cooling passage
, then maybe you could get what looks like steam in the coolant tank without elevated engine temperature. It looks like overheating
because the exhaust in the coolant seems like steam and overheating
. Pressure testing the engine cooling
system; however, would usually detect this. To be sure, get a crack testing kit from an auto supply house which checks for carbon dioxide in the coolant tank. If you find carbon dioxide, you know you have a crack. Do you see any coolant in the oil
? Sometimes it settles in the oil
pan so you need to drain or maybe pump some oil out of the bottom of the oil pan with a hand transfer pump and see if there is any coolant. Depending on the type of detergent oil, you will also get an oil emulsion that looks milky.
getting into the combustion chamber can work its way past the piston rings into the oil so that's why you look for coolant in the oil pan. Be aware that antifreeze
in the combustion chamber will form acid that attacks the bearings, so do not wait too long to check on coolant in the oil pan.
It might be you temperature gauge is not very sensitive. You could purchase
something like this: General Tools IRT207 Heat Seeker 8:1 Mid-Range Infrared Thermometer. I just bought one from Amazon and like it for checking automatic transmission
temperature after pulling a boat out of the water
on a trailer. Do not want that temperature above 250 degrees Fahrenheit on an automatic transmission
. The infrared thermometer could also be used to check for engine temperature.