My wife drives a 2015 Durango AWD Citadel 3.6 Flex with 148k miles, owned since 40k Recently it has started a surge/jerk/misfire symptom in the 1500-2000RPM area, at least every time i drive it that's where it happens, trans gear does not make a difference, we had the transfer case replaced last year at around 130k. I had a misfire Cyl5. Replaced all coil packs on passenger bank. Prior Repair history on the engine was I did the drivers bank of coils several years back, 2018 or so and probably around 80k miles, along with those 3 coil packs I did all 6 plugs. With the Cyl5 misfire(only code) I had no hurt feelings replacing the remaining 3 packs (all delphi) but not the plugs (NGK). Fast forward the issue is still present and now had set a Cyl 2 misfire fault (only fault) . I had read online about protentional crank position sensor failure occurring in the 1500-2000 RPM range, so perfect bought the sensor and installed. Fast forward issue is still present but currently no faults.

I believe this issue was occurring prior as she had complained about a jerking issues but I'm not for sure, I had not driven the car before the engine repairs. the engine developed a tick around 140k, last fall, I just recently 2-3 weeks ago, replaced all rockers and lifters, finding one failed roller bushing in a lifter. There was no cam lobe damage at this point. I used Melling lifters/rockers. I did not remove the cams to install other then loosening the caps and lifting on cams as needed by hand.

 

Well it appears I have found/fixed the issue. I'm not happy about this but should've checked it. Spark plugs gap out at over .080" (guesstimate) something. The pictured feeler is a .032". All plugs in similar condition. With only 40-50k on these plugs I feel this is a little early but maybe not. The pictured plug is an NGK Lazor Iridium, the number doesn't match what I'm finding is correct to the car but I'm not sure about it all. Replaced with an NGK 9723 gapped at .041"

I guess if it starts missing again in 40k I'll start here first.