It appears my intake manifold is leaking on the 2000 Expo, 5.4, 2wd, 123K. Yesterday, my wife calls tell me it's running rough. She plugs in the reader and we got P0301, I tell her it's cyl 1 misfire. This morning, I verify P0301, replace the COP just because I have one, and blow clean the plug hole.

After taking a closer look, I see the valley has water and I see it dripping from the passenger side crossover area and see traces of water on the injector, valve cover hold down nut, and that general area. I regularly look in the valley for water and this is the first time it was wet. I've read about the cracking and/or warping in the crossover area and I'm wondering what direction to take. It's blowing steam out of the exhaust similar to a blown head gasket, so I'm assuming that water is leaking into the intake in the cylinder 1 location causing the misfire and moisture out the tailpipe. There is no evidence of water on the dipstick and no oil floating in the coolant tank.

Sorry for the dissertation, but my question is..... should I take a chance and replace only O rings and gaskets only, or install a new Dorman intake. I've read pretty good things about the Dorman, but I usually like to install Ford parts (except for the COP ) What if I have a blown head gasket and this was all for not? Your recommendations are appreciated.

 

I can speak from experience on the cracked/leaking intake crossover. If its cracked, good chance its due to change. Ours is a 2000 Expy, with 206000 miles and it went south 6k miles ago. I say replace it with a Dorman, but wish I had spent the extra money on a Motorcraft intake. Still happy it got the job done at just under $200.

 

The Dorman is $173 on E-Bay and $250ish local, while the Motorcraft is $489 at the dealer. Probably go with the M/C.

 

When yours was cracked, did you have the same symptoms as me? Was it only leaking on the outside? Was it leaking into the intake causing a misfire?

 

I'm curious if anyone has used JB Weld to repair a cracked intake?

 

The symptoms were same, but luckily wasn't being sucked into the intake. Also, there was a big chunk of busted intake underneath the thermostat when I removed it. After removal of intake, it was obvious it wasn't worth any type of patching. With all the time in nice weather it took to carefully remove everything, I wouldn't want to chance it leaking again.

 

Mine cracked at just about 80000 and dirtied the motor. It wasn't until I noticed the coolant loss 20000 miles later that I changed the manifold.

 

I had a piece of the manifold in the crossover under the t-stat as well. I'm sure JB Weld would do the job, but for how long? And is it worth digging that deep to save $500? I have pics on my Smugmug for a JB Weld repair I did to my DR650 case. A rock blew a big hole in the case and I patched it with JB Weld quick and JB Patch putty. It's still holding after 2 years.

I didn't want to drive with it leaking into the cylinder as I didn't know how much was leaking. A hydro-lock or a blown head gasket was on my mind. I replaced the valve cover gaskets, heater hoses, and plugs since I was in there.