Hey guys. Lately I've been getting the P0171 and P0174 codes thrown at me. I found the cracked rubber elbow on the PCV system. Today as I was taking it off, I realized that I had to remove the smaller vacuum line above it to gain access to the cracked elbow. The smaller vacuum hose attaches to the same place as the cracked rubber elbow, but on a smaller T/pipe connection right above the cracked elbow. When I removed this hose, I had about 1/8th of a cup of coolant come shooting out of where the smaller hose hooked to. What does this mean? Do I have a leaking intake gasket or what? The truck uses no coolant at all.



GB :)

 

The forum won't let me subscribe to this thread. WTH??



GB :)

 

I believe that the "vacuum line" that you are describing above the PCV elbow is actually a coolant line.

 

It seems to go into the same metal line that the larger (cracked) rubber elbow does. Unless that connection is a jacketed line. An inner and outer layer within the same pipe, both going into the upper plastic intake.


I trust your judgement for sure Bob. It just seemed very odd to me.



GB :)

 

Yes, it should be heat jacketed to prevent water vapor from condensing and then freezing at the PCV discharge into the intake. There's also a "horseshoe" heater tube wrapped around the PCV valve on the back of the driver side valve cover for the same reason.

 

Ok. Thanks for the info Bob. I appreciate it! It just didn't make sense to me that there'd be a coolant line that seemed to go into a plastic intake.


GB :)

 

I don't have a 4.0 here to look at but I think you'll find that there is a coolant line above and below the PCV elbow (one inlet and one outlet).

 

Yes. I've changed not only that vacuum line and elbows from the PCV valve on the back of the drivers valve cover to the throttle body area but also the PCV valve itself. It does have that loop/horse-shoe of coolant metal line around it to warm the system faster. More of an emissions type idea. When removing the valve you have to remove the two little lines off of the horse-shoe as the new valve will come with a new one on it. It will drain the tiny bit of coolant out of it, no big deal.

I took a few pics when I changed mine...
https://www.ranger-forums.com/4-0l-ohv-sohc-v6-tech-33/spark-plugs-changed-pvc-valve-how-pics-112415/