There's another similar thread started by Lennyg, but I think my question is going to be different.

I have a 2001 F150, 4.2L V6, 2WD with about 130K miles. I have what seems to be a classic coolant leak, where the pipe with the 90-degree bend that introduces coolant to the intake manifold is leaking. It's about 20 degrees out, and I have no appetite for pulling everything. Instead I want to just bypass the coolant around the manifold. I've found lots of posts saying this is possible. Just disconnect the coolant inlet and outlet hoses from the manifold and connect them together.

What I haven't found is where that outlet hose it located on the manifold, and Haynes is no help. I thought I knew where it was, but after I connected what I assumed were my inlet and outlet hoses together my engine spews coolant out of that outlet fitting. It must not be the manifold outlet, but is instead connected to the main cooling circuit.

I found a photo of a new manifold:


At the top right are two coolant fittings. The 90-degree is the one that's leaking. The horizontal one adjacent and pointing to the right is what I thought was the outlet. But this fitting keeps spitting out coolant. I don't see anything else though in this photo that would be another option.

Any ideas?

Thanks!

Mark Salvetti

 

mine is leaking in the same place i used jb weld around the leak
the coolant through the manifold also cools the headds

 

Thanks, I realized that not long after I posted. I think the intake manifold bypass I was reading about was only for the hoses that come off the PCV valve and go up to the throttle body.

My leak was pretty bad; just tugging on the hose and the 90-degree pipe bent over. This time of year I just don't have the time (or the desire - it was 20F outside) to pull the entire intake manifold myself. Local shop couldn't look at it for 4 days, so I had the truck towed to the dealer. They fixed it in one day, but at a cost of $150 in parts and $550 in labor. Ouch.

Thanks for the reply,

Mark

 

I am having that same problem now at 140k miles on my 2002. Sounds like I will be doing my own though. Is it the braced joint onto the intake or is it pipe corrosion?

 

How is the leak now? Any issues?

 

I my case the pipe itself had corroded, and broke flush with the intake manifold. I don't think JB Weld would have helped. I think you will have to pull the manifold and drive out the old pipe, which is a press fit.

After over 15 years driving 2WD F150's, I sold the truck the month after it was fixed and bought an AWD RAV4. So nice not having to abandon the vehicle at the bottom of my hill in snowstorms (often the case with my F150's), and routinely getting 22-24 mpg, instead of 16.

Mark

 

Just repaired this in a couple hours without removing intake. Take a long flat blade screw driver. Heat it and bend it 90 deg. Break the pipe off at the manifold. Use the screw driver and a hammer CAREFULLY hammer it down. Remove the thermostat housing and pull out the remaining piece of tube.