hey yall,

A few days ago, my truck started misfiring on cylinder 8 and threw the CEL. When I popped the hood, I noticed a coolant leak at the thermostat housing. Upon further research (and this board) I have determined that the leak is coming from a faulty intake manifold/crossover, which I have ordered the Dorman replacement for.

While disassembling the parts to remove the intake manifold, I found what seems to be a vacuum line with a check valve on it, just laying on top of the intake. It comes out of the same harness as the vacuum hose going to the fuel rail sensor on the passenger side. circled in the attached picture. Any idea what that is? Thanks in advance.

 

Get actual pictures of your truck, not just diagrams, and tell us what engine you have

 

I will post actual pictures later today when I get home from work.

Its a 2007 with the 4.6 2V. 2WD

 

 

Its for an IWE system if you had 4wd. They will use the same harness on multiple styles, yours just ended up being 2wd instead of 4wd. Causes a lot of people concerns wondering what it plugs into. Good luck with the coolant leak.

Tom