Coolant leak with video showing leak spots | Ford Explorer Forums - Serious Explorations

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September 24, 2016
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Year, Model & Trim Level
1999 Explorer 5.0 AWD XLT
New to the forum. I live up North and am trying my best to winterize my car before the snow starts. For a year now, I have noticed that my coolant level drops in my explorer very quickly. Last winter I had to fill it up with one entire jug of radiator fluid every 3-4 weeks. A year later, my engine will lose it every 300 miles and has overheated twice and now I fill it up every week or week and a half. When overheated, the temperature indicator went to H and then I heard a loud clicking noise. I fill it up with a jug of coolant, and it doesn't overheat.

I pressure tested the system cold last week. I found multiple leaks.

first leak: either next to or on top of the water pump (see video and pictures)


second leak: underneath water pump and above heater core. Multiple hoses possibly?




third and fourth leaks (majority of coolant loss): dripping from the drivetrain (see video) and other piece of equipment next to drivetrain.





So far my hypothesis from reading other forums, a lot of googling, and reading the haynes manual: freeze plugs between the drive train and engine, hoses near the heater core, gasket issues. My engine also has a block heater, so this might also be a possible coolant leaking area.

If anyone has suggestions for either diagnosis or solutions I am all ears! I can also take more pictures/video if you would like to see the engine at a different angle.

The leak behind or on top of the water pump could be from the short 90 deg hose connected to the pump. Barring that, it's likely to be failure of the gasket between the timing cover and the block. This is very common for the 5.0L engine. I would advise to blow all that coolant pooled up there with compressed air and repeat the pressure test, looking very carefully for the source.
As for what you are calling 'the drivetrain', what makes you think it's freeze plugs? There are no freeze plugs in the back of the block of the 5.0L engine. I believe that there are plugs at the back of the heads, but those are pretty easy to see. I can see coolant dripping from the bottom of the transmission bell housing, and most likely, this is the result of the leak at the front of the engine. Because of the angle the engine is mounted, coolant that's leaking at the front will follow the lip of the oil pan and end up dripping there.