Explorer v8 coolant leak


5th Gear Poster
Lifetime Supporter
Sep 22, 2023
Vehicle Details
96 Cougar 4.6L
Country flag
Posting here since some of ya'll have experience with the Ford 5.0:

This is on ol' Red, she's been marking her territory for a little while now, it's been small spots. Last time I did some work on her I replaced the hose clamp on the lower radiator hose where it connects to the water pump thinking that was it. It was not... I borrowed a pressure tester today and when pressurized there is noticeable leaking, but I can't figure out from where.

Underneath the dripping falls onto the drivers side steering rack bolt then runs down the subframe. There is a small puddle that develops on top of the block next to the cam synchronizer behind the bracket that holds the power steering pump and ac compressor. See pic below, I'll follow up with the pic.

It seems like wherever it's leaking from it's pooling in that spot then dripping down the front of the engine which made it look like it was coming from the hose connection on the water pump. With the system pressurized I don't see any bubbling in the puddle nor any squirting of fluid. There's not alot of room around there to search around.

Any thoughts on where the leak might be?
Possibly the thermostat gasket, or intake manifold gasket, or possibly the bypass hose that goes from the water pump to the thermostat housing. Could also be timing cover gasket. All of those are in that general area. I would clean everything up real good, then pressure test again while watching it to see what gets wet first.
I sopped up that puddle, then pressurized again and it pools right there till it drips down. This gives me a few things to look at, currently it’s a very slow leak.

Bypass hose looked good (short right angle) & it’s clean around the thermostat.

removing the coil packs might get a little better view any other suggestions on things to remove to see better?
Last edited:
I'm waiting on the pics.
I have my daughters replacement 5.0 on the stand right now to look at. Have you done any work to this engine?
Because it could be one of the two coolant temp sensors, the coolant tube for the heater hose. the thermostat. Could be bad intake manifold gaskets or even the timing cover gaskets.
any history worth quoting here?
Not personally and for sure not recently. I’ll look at the records the PO gave me.

If intake gaskets would you expect higher than normal fuel trims also? Last I checked those they were good. That’s been recent.
Yeah… at least this ain’t the first time I’d be pulling a timing cover, so it ain’t scary no more…
Yeah, the only concern with that is a lot of times the bolts that go through the water pump and timing cover seize due to rust, and like to break off in the timing cover. Just take your time, use lots of heat, and work it back and forth, or just cut it off and buy a new timing cover.

Similar threads