Rough Idle Due to Cracked PCV Hose on Ford Expedition

Problem Description and Possible Solution

The Ford Expedition is known for idling roughly, with a slight whistling noise from the engine compartment. After a short time, this may result in poor fuel mileage, and illumination of the check engine light

This is caused by a cracked positive crankcase ventilation (PCV) valve hose, which allows a small vacuum leak, and improper evacuation of engine crankcase pressure.

Correction is simple, and requires replacement of the PCV hose. An updated part may be available. 

Problem Data
RepairPal Verified
Average mileage: 152,083 (110,230–218,000)
Engines affected: 4.6L V8, 5.4L V8
8 model years affected: 1997, 1998, 1999, 2000, more2001, 2002, 2003, 2004
33 people reported this problem
Viewing 1 - 11 of 11 comments
Rough idle, stalling on my 2000Expedition. Code came up as PO171. Found a leak in my PCV hose at bend. This is a Ford only part. Went to local Ford dealer and ordered the hose with the PCV valve included. Replaced it myself. Problem solved.Ford part # 2L1Z6758GA.
idled roughly, would die after idling for a few minutes, but when going down road would drive fine. pcv hose broken and was replaced, fixed problem
Rough idle after plug no.3 blew out replaced plug with new one and notice the pcv hose was cracked and has a vacuum solenoid attached
Was having problems with truck rough idling, then started to die. Took it to our mechanic said it was the main hose to the engine.
I had extremely rough idle and most of the time it would not idle. I replaced the PCV plastic line with rubber hose. It has fixed the problem.