lrschoen

Hi all, new member here, happy to be part of the community. I've spent many hours scrolling posts here, particularly related to my ongoing issue: low-RPM shudder in my 2011 Ecoboost, Super Crew, 84k miles. I KNOW, I KNOW... I'm only posting again because I've done the gambit, and am still experiencing the issue:

• New Motorcraft plugs, gapped 0.30
• New coils packs (all-including boots)
• Cleaned MAP sensors - even replaced one on intake manifold that was just barely dirty
• CAC weep hole drilled (even though I live in AZ and it's rarely humid)
• CAC flushed, cleaned, dried
• Rx dual-valve catch-can w/CSS installed

Plot twist: Recently discovered that disconnecting the positive battery terminal for 45 minutes eliminates the problem for a couple days, but only for a couple days. The shudder always returns to haunt.

Thoughts? Suggestions? Thanks in advance!

Meathead

iTrader: (2)

You need to drive it more aggressively. Don't grandpa it.

Tothemax

Describe the shudder to us. How are you driving?

Deerhunter4

Have you ever had the PCM flashed to a newer or updated version? Dealer will charge but it may be worth it. Sounds like you've done everything else to resolve the issue. Maybe try to datalog to see which cylinder is misfiring? Hope you get it figured out.

lrschoen

City driving, mostly. Moderate driving, not too aggressive. The shudder hits hard at around 50 mph when it settles into 6th gear, hard enough to rattle the change in the console.

lrschoen

Good suggestion, this is probably where I'm headed. Haven't had great experiences with dealerships in the past, but I'm low on options. Thanks for the feedback.

Tothemax

Are you sure its not transmission?

Tothemax

Especially since you say it goes away when you disconnect the battery. That resets the KAM.

Do that again and drive it aggressively.

lrschoen

Yes, it's an irregular and intermittent studder, not rhythmic, and it goes away completely for a time with a KAM reset. Good thought though, I went through the same analysis.

lrschoen

Interesting. I'll try that today. Thanks