I have a 2008 dodge dakota with the 4.7 and i'm having some issues with it. About a year ago I noticed my truck was idling rough in the mornings when it was could out. I did the usual tune up to it (plugs, wires, filters, etc) and none of them seemed to help. After some time it started making a knocking noise when cold that would go away after the truck warmed up. Fast forward, the truck has been to 7 different shops and every mechanic says the same thing, they can feel and hear the issue BUT they cant find whats the cause! Now the truck does the same rough idle when cold and knocking for a bit but it also now has a different problem where after the truck gets to operating temps it feels like i'm pulling a huge load, the truck hesitates and engine bogs way down. Any feedback is highly appreciated. Thank you.

 

... hmmm, sounds like you may have one of those with a leaking head gasket, which gets progressively worse potentially leading to piston/valve damage. Or a set of spark plugs that are worn out, burnt off near completely. A couple of things you could try.
- What is your coolant level doing as well as the cleanliness and color of the coolant?
- What is your oil level doing as well as the cleanliness and color of the oil?
- On a cold start when it is knocking and making a mini-fit: shut it off and pull the each of the spark plugs. What you are looking for is which plug(s) look wet or black with build up on it.
- Have each cylinder checked for compression. Compression test numbers are the #1 tool to indicate which cylinder(s) could be having issues, causing the low power bog.

Start with those, next steps or next tests are totally dependent on those results.

It is surprising (appalling actually), if not one of the 7 shops mentioned performed these basic checks. If all they do is read the computer codes, of course they cannot find anything wrong, 'cause there are no codes for this problem.


Hope that helps!

 

Have you cleaned the throttle body?

 

I've cleaned once and it didn't help any. I was wondering if its a oil lifter? I'm not sure if that will cause the rough idle. The engine now runs rough with no power. I did notice it ran better when I turned on the tow/haul option.

 

sounds like a rocker fell off, or is loose, start pulling coils and see what cylinder doesn't make it stumble, might be your issue or even a faulty coil itself, also check all fuel injector connector, one of those could be faulty or clogged, another issue could be a clogged cat convertor.

 

Have you fixed this yet

 

I would start with the know issues with these engines,
duel detonation sparks and exhaust manifold leaks, back compression will rob engine of power ... same with bad coils/plugs but you're not throwing a code so I'd go with exhaust manifold leak