Leaking coolant | Ford Explorer Forums - Serious Explorations

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Leaking coolant


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June 10, 2015
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Year, Model & Trim Level
2015 Ford Explorer XLT
I have a 2015 explorer xlt , just hit 100k and I have a slow coolant leak!! Help

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More info please

If you cannot see the leak, get a coolant pressure tester. Put 15 psi on the system and look for puddles on the ground.

I have a 2015 explorer xlt , just hit 100k and I have a slow coolant leak!! Help
Welcome to the Forum. :wave:
Can you tell where the leak is coming from? Not that I want to alarm you but check out this thread; Water pump failure leads to dead engine
Check the oil on the dipstick to see if there appears to be any contamination.


As Peter stated, check the oil for coolant. Due to the water pump being located internally on the 3.5L V6s they will leak coolant into the oil lubrication system when they fail. Many, many of these engines have suffered catastrophic failure due to the pump going fast and dumping most of the coolant into the crank case. You might be one of the lucky ones and it is failing slowly thus allowing you to identify the problem early. I wouldn't drive it except to get it to a shop and have it checked out. If you no longer have an extended warranty then Ford will not help with a repair in any way. A dealer might if you have a long term relationship with them but even then it is sketchy. Replacing a water pump in these engines isn't easy and typically runs $1,500-$2,000 just for the pump replacement. Most choose to replace the timing chains and guides while it is apart and that raises the cost around $500-$750 for the new parts to be reinstalled. If the engine goes then the repair tab will likely go to $6k-$8k for a replacement engine. There is a long thread on the 5th gen forum that covers this situation that Peter referenced. It might be worth reading.

I have a 2015 explorer xlt , just hit 100k and I have a slow coolant leak!! Help

If you know you have a coolant leak, do not run the explorer till you know if it is internal or external. If internal, you can blow your motor.

This is not necessarily needing to be tackled as Explorer specific as suggested. There are only 3 main places the coolant can be going. Either it's leaking externally which you should be able to see unless it is so slow that it's smoking off instead of dripping (then you should see residue), or leaking internally either into the oil or into the cylinders and then out the tailpipe.

If you cannot find the leak yourself (not an obvious source like dripping from a hose or radiator), then it is time to take it to a shop. Certainly you should check the oil and if it looks like a milkshake, then I would change the oil and put a "few" miles on it before driving very far to take it to a shop, to be sure it isn't leaking badly enough to cause damage on a longer drive.

This goes for any vehicle with any water pump design, there are more ways than one that coolant can find its way into the oil, or get sucked into the cylinder(s) and cause hydrolock, or foul the catalytic converter and O2 sensors, etc. Say you were to hydrolock the engine... it's not going to be much consolation that (if) it wasn't the water pump leaking.