Hey, Guys,

My '04 6 cyl. has recently been running a little rough. Not really a miss, and not hard to start, but just not as smooth as it has been running.

It has 85k miles, and I have not done anything to the engine.

My question would be where would start looking for improvement? Is it time for plugs? Is there anything else to check.

I would like to be able to do a fix myself without my dealer.

Thanks for any ideas!

VaDon

Some folks say the plugs are good for up to 90k miles but I would start with new plugs. If you have a 6cyl the back 3 are hard to reach.
Clean the Mass Airflow Meter
Replace the PCV valve
Clean the throttlebody.
Replace the front oxygen sensor.

Thanks for your help. I appreciate any ideas!

VaDon

Has anyone replaced the back 3 plugs without removing the intake mfold? Can this be done without pulling the intake manifold on a '04 V6?:unsure3d:

Unless the idle is lumpy and irregular, or you are getting definite misses during acceleration, then leave the plugs alone until 120k.

More likely the "roughness" is due to hardening motor and transmission mounts and radiator hoses, which transmit more vibration to chassis as the car ages.