Mystery Coolant Leak 3FE Drivers Side (1 Viewer)

Joined
May 4, 2020
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Los Angeles
I was poking around my driver's side bay when I noticed something that looked similar to coolant just hanging out on one of the mounts. Any thoughts as to where the source of this leak could be? Anything above the leak location is dry and doesn't seem to have any coolant hoses above.

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Joined
Nov 9, 2012
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10,559
Location
Olathe, KS, USA
What do the freeze plugs look like? I'll check these as well. Is it easily distinguishable?
These are round steel plugs in the side of the block, about 1-1/2 in diameter. I don't recall if there are 3 or 4 on the side.

They are also referred to as core plugs or welch plugs.
 
Joined
May 4, 2020
Messages
239
Location
Los Angeles
These are round steel plugs in the side of the block, about 1-1/2 in diameter. I don't recall if there are 3 or 4 on the side.

They are also referred to as core plugs or welch plugs.

doesn't look like the block plugs are leaking, kind of odd because i can't trace anything to the coolant leak over there. I'll wipe it up and try again tomorrow to drive it around and see if I can see anything.
 
Joined
Nov 9, 2012
Messages
10,559
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Olathe, KS, USA
Thanks! Those are the ones I checked - they're a little hard to see so I'll try to drive around a bit tomorrow to see if there's any coolant trails after driving around
May also want to get a mechanic's telescoping mirror so you can reach it under hoses and shields and shine a flashlight on there to see if you can spot a leak.
 
Joined
Nov 22, 2020
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Birmingham
On the 3FE, there is a 6-inch long, 5/8 inch inner diameter rubber hose that connects the drivers side bottom of the water pump to the metal line that goes to the oil cooler. This rubber hose sits on the block behind the alternator and front of the exhaust manifold on the drivers side. You can only see it from under the truck and look up from the drivers side of the crank pulley. This started as a small coolant leak and I couldn’t find it, then got worse through time. This hose gets hot and swells (runs along block) and becomes brittle, then leaks. To get to it, I had to remove the smog pump, then alternator, and you will see the small hose. I cut it out and it was a little difficult to get the new hose installed. I had to heat the replacement hose with a heat gun to get it flexible enough to get back in the 6-inch gap between the water pump and metal oil cooler line. Used compression clamps on the new hose. Not too bad of a job just search alternator removal. Ping me if it may be this line.
 
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