Hard to find coolant leak. Help

[Sawtooth763]

Need help determining the source of a coolant leak on my 02 Explorer XLT 4.6L V8, w/ 110,000 miles on it. Drips are coming from somewhere on the driver side because I am seeing the actual drip (when under the truck) coming off of the part of the trans that bolts up to the engine. When pressure testing at 15psi, the drip, drips faster naturally, and about 2-3 psi is lost after about 20 minutes.

Does anyone know where it might be coming form. I'm thinking the plenum but would like to be sure before replacing it.

Thanks

 

[swetrid]

Which engine?

 

[Sawtooth763]

4.6l v8

 

[BradR]

I had a similar issue with my truck, 4.0 ohv v6, drip was on drivers side, but the leak was on top on the passenger side. Turned out to be my heater control valve. The coolant must have dripped out an ran across lines and whatever to the other side. Not sure if this helps, but good luck.

 

[Sawtooth763]

Brad,

Thanks, how did you determine it was the heater control valve.

Was it from a visual inspection.

 

[Sawtooth763]

Found it

Leaky intake manifold.

Thanks everyone