2017 F-150 V6 3.5L XL
106K miles
​​4x4

My truck has 106k miles and Im on my 3rd coolant leak since surpassing 100k miles. 1st leak, complete degradation of the lower intake, creating a large enough leak the vehicle had to be towed. 2nd leak, Y-Pipe in the Heater hose failed, small leak that allowed vehicle to limp home. 3rd leak, still diagnosing but appears to be a failure in the plastic on the side of the radiator. Honestly, getting to a point of just getting rid of the vehicle. I find it ridiculouse that within 6k miles Ive had 3 coolant leaks all due to plastic being used throughout the system (including the lower intake). Im curious to see if anyone else has had constant issues in regards to their cooling system in their truck?

 

Why did you have the truck towed - did you need to go far to get to a shop? These trucks will run without coolant, in fail-safe mode at reduced power. Basically when the engine reaches a certain temperature it deactivates half the cylinders, so they act as air pumps and air-cool the engine. One of the radiator hoses on my 2011 F150 burst and dumped all my coolant (the only issue I ever had with the cooling system) and I just drove it to the shop, which was within 10 miles on surface streets.

 

I was over an hour away from home, hence the tow. On this engine the lower intake acts like a through from the heater core to the front of the engine where the water pump is from what I understand. The lower intake is plastic and the pipe through split all the way along the pipe. (Honestly feel like an external hose would have been a better option here than engineering the lower intake in this manner).

 

You have a good point, and I feel for you having 3 leaks in 6K miles. An external hose would certainly be cheaper to replace. I don't recall reading about that being a common problem.

 

You did the right thing tow it.. your cooling system gripes likely from someone putting water only causing all the corrosion.
my 2015 never used a drop. My 2018 same and due for flush. Somehow your cooling system did not have proper mix.
my 2 cents.

 

who is working on it? They have to be complete & utter morons to not address the original problem... so blame that on whom ever felt an ounce of prevention wasnt worth the lb of cure.
Your shop has poor diagnostic skills.

 

I put over 172K on my 5.0 2013 and only had 1 o ring leak at the "y" connector and then later on, had that same piece replaced under warranty. I also maintained the coolant system about every 30K with a flush and refill. It was not until about 130K that I replaced the waterpump, tensioners and hoses as a "maintenance" thing and not out of any need because of failure.

Every winter, this forum sees the posts about "o ring leaks," increase.

 

Feel your pain OP. In the last 25k miles I have replaced the y-pipe, water pump, and degass bottle cap. Found a small leak a few weeks ago in the side of the radiator under the upper hose connection on the plastic part. Was topping it off as needed, was very slow leak, until I could get around to replacing it. Well, the universe forced that on me last week when the temps were 100+ on my way home in the city, and it overheated as a I was making it back up the mountain, limp mode and all. Was within 5 miles of home, but still some steep grade to get there so I had it towed. Anyway, installed the new motorcraft radiator Saturday, and found a heater hose was also leaking after I had it filled back up and testing. 🙄
Picked up said heater hose and about to slap that on, but stopped to rent a pressure tester before refilling coolant yet again.... at least it'll be well flushed!

Leaking right on the plastic knuckle