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JB1
New User
Jul 8, 2015, 8:27 AM
Post #1 of 6
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2002 Dodge Dakota 4.7 V8 Magnum 145k My son was given the truck with a known vibration at certain speeds. The previous owner thought it may have been the tires and replaced them prior to giving the vehicle. I fixed a couple air leaks in vacuum lines, changed fluids and filter and changed the plugs. Trick still bogs and runs rough at certain speeds, especially close to shifts. Took it to a mechanic and they showed a code (that my ready wouldn't pick up) that said misfire on cyl 4. It feels like a bad cyl. I could change the coil, but it seems more than that. The mechanic wanted to run a compression test , but then they said that would only tell them so much and would need further work after that. What are my options? Should I just be looking to rebuild the engine and forgo the drawn out drama? Thanks for your thoughts. Briley
(This post was edited by JB1 on Jul 8, 2015, 10:21 AM)
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Hammer Time
Ultimate Carjunky
/ Moderator
Jul 8, 2015, 8:56 AM
Post #2 of 6
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Re: Dakota - Bad Cyl
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You would be smart to change your user name or the spammers will have a field day with it. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
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JB1
New User
Jul 8, 2015, 10:20 AM
Post #3 of 6
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Re: Dakota - Bad Cyl
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Done. Thank you. I don't use these sites so didn't think that far in advance. Also - I'll correct my post - this is a 4.7 V8 Magnum motor.
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Tom Greenleaf
Ultimate Carjunky
/ Moderator
Jul 8, 2015, 10:27 AM
Post #4 of 6
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Re: Dakota - Bad Cyl
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Briley! Just what are you going to rebuild without knowing what's wrong yet? First clue might have been what spark plugs looked like compared to each other. Oil fouled, wet with fuel and so on are telling alone. If this tech doesn't think a compression test and other tests can confirm what if wrong find another. Yes, one cylinder being erratic will make whole engine feel lousy but too early to blame whole engine. IDK - still thinking. Check anything connection wise unique to that cylinder - fuel, spark CONNECTIONS and look at the plug again if needed. If your reader won't read that you've found it and it always picks on cyl #4 you'll feel it in tailpipe puts that it there now and gone when fixed. I can't believe it's up for an overhaul yet at all, T
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JB1
New User
Jul 8, 2015, 10:33 AM
Post #5 of 6
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Re: Dakota - Bad Cyl
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Four was dirty and did have a slight fuel/petro smell.
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Tom Greenleaf
Ultimate Carjunky
/ Moderator
Jul 8, 2015, 10:55 AM
Post #6 of 6
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Re: Dakota - Bad Cyl
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So far so good. That suggests lack of spark so far to me or checking on that first. I'd also spray around with either or one at a time carb cleaner and *Brakleen (brand named) for vacuum leaks - gaskets and anything suspect. Note: If intermittent with a leak carb cleaner will likely make it run better if one found or small change. If leak is unique to that one cylinder read Brakleen or others as they kill fire and say so on containers of off name brands too of brake cleaner but some are flammable. As said try to rule out anything close to or unique to that cylinder. Swap tronics with one that works and see if the problem follows. There's lots you can test to narrow it down without going too nuts yet, T
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