2012 V6 Explorer rough idle

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Apr 23, 2019 | 09:25 PM

bulldogcountry1

Thread Starter

Tuned

Joined: Feb 2002

Posts: 441

Likes: 0

From: Vicksburg, MS

2012 V6 Explorer rough idle

Starting a few months ago, my Explorer started idling rough at times and would throw a temp error code under hard acceleration. I was finally able to get the error code with an app, and it was a cylinder misfire. I went ahead and changed the spark plugs with Motorcraft, and it ran like a top for a couple weeks. Well, the rough idle has suddenly reappeared worse than before. I haven't been able to force an error code, though. Is it possible that a plug went bad? What else could it be? Vacuum leak? It feels normal under normal driving.

Sep 30, 2023 | 06:50 AM

Zorba 1968

4wd High

Joined: Aug 2023

Posts: 9

Likes: 2

Sounds like the issue I had with my 2003 Explorer. The spark plugs I had put in were motorcraft and the car ran fine for a few weeks and then the rough idling. The mechanic I brought the car to in Binghamton tested and found the bad plug on the 1st cylinder. He changed it and replaced a small vacuum hose for $100 and now the car runs like a charm. He said he's been seeing Motorcraft spark plugs going bad after tune-up. Could also be the ignition coil. I'm starting to think that it's better not to do the tune-up on the older Explorers unless there is a problem.

Sep 30, 2023 | 07:46 AM

shorod

Logistics Pro

Joined: Jun 2009

Posts: 4,817

Likes: 83

From: Cedar Rapids, IA

There are several things that can cause a misfire. Typically it will be spark plugs, ignition coils (one per cylinder on your 2012), fuel injectors, or a vacuum leak. A higher end scan tool would allow you to monitor misfire counts on each cylinder in real time, even if the misfire counts are not sufficient to trigger a check engine light or diagnostic code yet. Once you know which cylinder is misfiring, then you can swap the ignition coil with a different cylinder and the spark plug with yet another cylinder then see if the misfire follows the plug, the coil, or remains on the same cylinder to further troubleshoot.

Was the code you originally had for a specific cylinder or was it a random misfire code? Providing the specific diagnostic code number is generally a good practice on forums as some codes stem from common issues on specific vehicles.

-Rod