Just changed out my PCV Valve and was wondering what the heck the tube is that raps around the Valve 2003 5.4

 

Coolant runs through it to heat the PCV valve.

 

Water heated PCV's, we started installing these in about 2002 and now have the regular PCV type that'll clip in place- more secure design. All it basically did was tie into the heater bypass tube and heat the PCV with coolant like a heater core/ hose.

 

Ok ... But why would you heat it?

 

Not sure really, we don't do this on every engine, for example the 2 valve engines made are reg. PCV but the 3 valves have a heated, not water heated anymore, more like a MAF heating for the PCV. All I can say is that's gotta be a small emissions improvement of some kind.

 

they draw the moisture rich air out of the crank case and at 20 below zero they freeze up. In 97-01? it was heated at the intake elbow after the throttle body. have the body up in the air right now and rebuilding the motor because two years ago we heavly recommended a coolant flush, green coolant now opaque orange like orange paint,( it is rust creating the color from anything steel it contacts because the corrosion preventer is worn out in the coolant) and the fitting rusted out and the motor sucked the coolant up into the motor and over heated it. sent oil out for analisys and they said the lower end is wearing bad, sure enough bearings wiped from coolant in the oil. Had the body up off the frame in 2.25 hours all by myself this time, I've done enough

 

Thanks Guys