intake manifold on 2006 Dodge Magnum

today i loosened the bolts on the intake manifold to change my plugs but realized it looked very complicated and didnt want to mess something up so i tightened them back up and called it quits. i later took off in the car and it began running very rough while stopped. Air leak? Broke a seal somewhere? What did i do wrong here??

by in Terre Haute, IN on November 30, 2009
3 answers 4 comments
ANSWER by on November 30, 2009
What engine size do you have. There's 4 different Magnum models. Which is yours.
COMMENT by on November 30, 2009
3.5L V6, what do you think?
ANSWER by on November 30, 2009
The first thing to do is double check and make sure anything that was disconnected / unplugged is reconnected properly. Vacuum lines, wire connectors, etc. If you removed the air tube, make sure that is secure so that no air leaks in after the MAF sensor. Without knowing how you torqued your intake, it's hard to say if you created a leak. There is usually a tightening sequence, and there is definitely a torque spec for the intake plenum and manifold. Did your Check Engine light come on?
COMMENT by on November 30, 2009
No check engine light, i tightened with a regular ratchet(didnt know i had to torque). Never disconnected any hoses wires etc... I only loosened the bolts, never removed the manifold. I loosened 7 bolts on the right side of the plenum, didnt touch the left bracket looking things that holds it to the block.Is there a seal between the plenum and block that could have been compromised in the loosening process??
COMMENT by on November 30, 2009
You can try to listen for the vacuum leak using a length hose as a stethoscope. One end goes into your ear and use the other end around the mating surfaces to listen for hissing or leaks (you might be surprised how well it works as a stethoscope). If you didn't drive very far, the monitor may not have run to set the light. Sometimes they take time to turn on. Manifolds and cylinders heads are usually tightened in a clockwise spiral, starting from the middle, moving outward. This helps to keep the part flat when tightening. If the plenum is composite / plastic, the torque is probably not a high value
ANSWER by on November 30, 2009
What was your orginal problem?
COMMENT by on November 30, 2009
I ran the car for awhile and no check engine light. what are other possibilities for random boggy idle at stops, less than normal acceleration, thump noises from the rear and poor gas mileage. I can also hear, what i think is, the plate in the throttle body closing when in lower gears, its a definate clank noise in the front, around the time the car shifts and sometimes between. any ideas?
Related Items:
I need to change my plugs on 2007 magnum, 3.5 what do I have to remove to get to the plugs?
PO129, P0401, P0107, P0108, P2172, P061A, P2638, SOME RESEARCH INDICATES THAT ALL THESE CODES ARE A DOMINO EFFECT OF P0129, WHERE DO I FIND THAT SENSOR