2003 4.6L Supercrew with (I think) the Romeo engine.

This truck has a special plastic PCV valve with a square section that allows the mechanic to "get a grip" with an adjustable wrench and remove it with 1/4 turn counterclockwise from the passenger-side valve cover. The value itself looks a bit dirty / varnished but the ball still rattles inside, so I'm cleaning it now, and I'll reinstall it tomorrow.

The PCV hose itself is quite large, and so is the outlet portion of the valve. I did not measure it but I think it's 1/2" or 3/4" inside. Either way, this hose is much larger than the typical PCV hose I'm familiar with, so I'm thinking that there must be a good reason for using such a large hose in this application (?).

There is no elbow on either end of this hose. One end is hose-clamped directly to the PCV valve, and the other end is hose-clamped directly to the back of the throttle body. Common hose clamps are used here ... and since this is the only place in the engine compartment where I have seen common hose clamps, I suspect that this hose was installed by someone else before I got the truck.

Today I noticed that the hose was collapsed while the truck was idling. Later when the truck was not running the hose went back to its original round shape.

This hose is very soft, so I think someone may have replaced the original vacuum hose with this one -- probably the wrong kind of hose since it fails to retain its shape under vacuum. Or maybe this hose is just so old that it collapses due to softening with age.

How can I tell if this hose is the original factory part?

If I simply want to replace it with a 2-3 foot section of similar (but much stronger) hose, what do I ask for at the parts store to insure that I end up with a hose that will resist collapse under vacuum? Is it just called a "vacuum hose"?

I don't think I can use a typical heater hose because they are designed to resist pressure, not vacuum, correct?

I'll have to replace this hose with a non-collapsing hose before I can tell if this indicates a possible vacuum problem, correct?

 

https://shop.advanceautoparts.com/p/...hTerm=pcv+hose

 

This looks more like an original replacement hose than the one I have now. Thanks.

 

You can get one WITH the PCV valve for less here.... No foam crap on the pipe though.



BTW, it is IMPERATIVE that you use a Motorcraft PCV only. The aftermarket PCV valves are junk.

 

Thanks for the suggestion. It looks like that part on Amazon is made for a 5.4L engine but I have the 4.6L engine. However, apparently someone with a 4.6L made it work because he posted this comment:

Then again, if I have to "make something work" because it's not an original replacement part I can think of cheaper ways to deal with this situation. For example:

1- I can buy a cheap long spring, such as the type they used to use on old wooden screen doors to close them, and slip it inside my existing hose. Then it won't collapse any more.

2- I can "make my own spring" by coiling a piece of wire around a stick or a straight piece of rebar, and slip that coiled wire inside the hose. Then I won't even have to buy a $4 spring!

Normally I prefer to use original equipment parts, but in this situation I might be wasting my time trying to fix something that's not broken. I just noticed that only the center part of the hose collapses -- so there's probably still enough vacuum space along the sides to allow the system to continue to work properly as-is ...

Could this be why I have never seen any error codes about this issue?

 

Worked fine on my 4.6 - not sure what he had to modify.

 

Just go to the parts store and ask for vacuum hose and replace it.

 

01kingranch.... Forgive me if I am wrong, but I think - to prevent collapsing - these lines need to be hard plastic on the PCV, don't they? Thought that was Ford's point in using it in the first place.

 

You could be correct, but I have seen rubber on other vehicles. Maybe these modular motors need the plastic. Good point white

 

Would a bad pcv make mine smoke at idle?