I recently got a huge coolant leak that leaks into the center of the engine. It's on the passenger side where the crossover mounts. I took off the manifold and fixed the leak with j-B weld and put new gaskets on. After I put everything back on, I started it up then it started running rough, really rough, it threw codes saying it was running lean, and there was a misfire on cylinders 7 and 8.

The same day : I took all of it back apart, and inspected the gaskets and manifold and I couldn't fine anything wrong, BUT the back passenger side cylinder was completely filled with antifreeze. Btw I was burning a lot of antifreeze. I cleaned it up again, tightened it to correct torque, and correct sequence, AND IT RUNS THE SAME! The engine runs rough, it shakes back and fourth, and I'm burning antifreeze. Is this a cracked intake manifold or what? Gotta make sure before I shell out 250 for a new one.

 

Sorry. 2001 Ford F150 4.6ltr V8

 

If the spark plug wells get water in them they can short to ground. The plug wells are deep and there are no weep holes.

 

Pull the plugs and use an air hose to air it out? Or do I need new plugs

 

Try to blow it dry without pulling the plugs, that way the water doesn't pour into the cylinder.

 

I took the manifold back off and used gasket sealer, I pulled a couple of plugs that had violent near them, some were seized in so I didn't bother, I can't afford to do a head job ya know?

I started the engine, and started pulling wires off of the coil packs to see which ones didn't make a difference, and it was on the passenger side on the very rear, switched the coils, cleaned the plug, and put it all back together. Now it's burning coolant again. And it's still shaking and mis-firing. I'll post a video and show you, it's got some weird sounds, and it shakes back and fourth pretty well. My guess is it is a cracked intake manifold, but how do I test that? I'll attach the video.