Misfire

Michael Manager Marysville, Washington Posted   Latest  
Unsolved
Driveability
2011 Dodge Durango Crew 3.6L (G ERB) 5-spd (545RFE)
P0300 — Random/Multiple Cylinder Misfire Detected
P0301 — Cylinder 1 Misfire Detected
P0303 — Cylinder 3 Misfire Detected
P0305 — Cylinder 5 Misfire Detected

I have this Durango in my shop with rolling misfires. sometimes cyl 1 shows a counting misfire at idle, sometimes cyl 3, sometimes cyl 5. only happens at idle and rarely 2 cylinders counting at the same time. have done all the preliminary tests, swapped coils, plugs, injectors, compression and leak down. everything looks fine. I have seen all the posts for the bank 2 cylinder having issues but very few concerning bank 1. suspecting lifter or rocker issue but just trying to see if anyone else has run into this before I tell a customer they need X hours of diag time for a vehicle they may just get rid of.

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Louis Diagnostician
Claremont, California
Louis Default
 

Greetings Michael. I ran into one of those a few years back. Really stumped me as well. I suspected a rocker issue, and the customer agreed to valve cover R&R for inspection. I found the rollers severely pitted on the suspect cylinders. Installed new rockers, and misfires went bye bye. Funny thing though, the engine was maintained rather well. Never could trace the cause of the pitting. I…

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George Diagnostician
Burnaby, British Columbia
George Default
 

Hi Michael hope you can use in cylinder pressure transducer if you compare bank 1 to bank 2 I think you will find you have valve sealing Issues with bank 1

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Richard Technician
Wpg, Manitoba
Richard Default
 

I have seen lots of camshaft, roller follower, and lash adjuster problems .Usually very evident with a visual inspection. If no pitting is found on the cam or roller followers then lash adjuster can cause this. I know the cylinder head for 2,4,6 had lots of problems but have run across guide and seat problems with the "odd number" cylinder head as well.

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Geoff Diagnostician
Lahaina, Hawaii
Geoff Default
 

Sounds like you forgot the most important and basic test for a misfire....the vacuum gauge. If the gauge bounces, you know you have a valve sealing issue and swapping parts around is a waste of time. Being that it is a Chrysler 3.6, that is almost assuredly the case here. We had one just a few weeks ago, and a call to the dealer informed us that the Jeep was covered by the 100,000 mile warranty…

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Jürgen Owner
San Cristóbal de las Casas, Mexico
Jürgen Default
 

Does the engine actually misfire or is it just randomly counting without true misfire? If the latter you might want to look for a distorted crank signal.....

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Darren Mechanic
West Allis, Wisconsin
Darren Default
 

B1 o2 sensor?

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Dean Mobile Technician
Ukuwela, Sri Lanka
Dean Default
 

if mechanical side ok ..How about checking EGR and idle Fuel trim .. Thanks..

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