PCV Leak
Thread Starter
Teching In
Joined: Feb 2020
Posts: 26
Likes: 2
From: SoMD
PCV Leak Quick question. Can a PCV leak cause start, idle, and run issues? I've been having issues for awhile now. Initially thought it needed to be tuned, did that. Then I still had issues. Replaced spark plugs, fuel injectors, MAP sensor, Crankshaft Position Sensor, and a couple of other things. Any thoughts? Thanks.
TECH Addict
Joined: Dec 2017
Posts: 2,191
Likes: 978
PCV leak (dirty side) = vacuum leak
PCV leak (makeup air side) = unmetered air bypassing the MAF
So yeah, if some part of the PCV system leaks, it can cause problems that seem like a vacuum leak, or various other problems that mostly show up at idle and other high-vacuum and/or low-flow situations. Wouldn't affect "max power" or WOT operation very much, if at all; but would potentially mess up idle and maybe cruise. Won't cause a starting problem.
PCV leak (makeup air side) = unmetered air bypassing the MAF
So yeah, if some part of the PCV system leaks, it can cause problems that seem like a vacuum leak, or various other problems that mostly show up at idle and other high-vacuum and/or low-flow situations. Wouldn't affect "max power" or WOT operation very much, if at all; but would potentially mess up idle and maybe cruise. Won't cause a starting problem.
