my 2000 f-150 5.4 v8 has a very rough idle on 2000 Ford F-150

idle is always rough, this problem started as a result of replacing the timing chains. Can this problem be a result of improper timing between the two cams. Could this be the result of a vacum leak.Truck has approx. 220k miles

by in Bakersfield, CA on February 08, 2011
1 answer 1 comment
ANSWER by on February 08, 2011
why did you have the chains replaced?? did one break?? I would start with a compression test first to check for valve damage. Yes. a vaccuum leak will give you a rough idle. the chains out of time will give a multitude of issues. Roy
COMMENT by on February 10, 2011
The chains did not break, they were worn and making noise, there was no valve damage. If the EGR is mounted directly behind the throttle body, I removed the vac line that attaches to a diaphragm actuator on this part, put my finger on the connector and felt no suction at all. Removing the vac line did not effect the idle.