New Guy Has a Problem

[onprcntr]

My wife has a 2003 with a 2.4. It has 128,000 miles (give or take) and I had the transmission fluid changed but not flushed at 100,000 and replaced the plugs at 100,000. A couple weeks ago the "service engine" light came on and the car started running rough. It seems to occasionally hesitate at take off and idles poorly at a stop. If you quickly shift into neutral the idle goes up and levels off (usually). The code reader said the oxygen sensor was bad so I replaced it and the light went off. I also did an oil change and changed the air filter, ran fine for a couple days and started running crappy again. This time the light stayed off. I don't see a loss of power and the car runs fine while driving but still has the idle issue while stopped in gear.

[Reelax]

check battery, check alternator, clean throttle body. also, if you haven't changed timing belt/ water pump, those are way overdue (should be changed every 60k miles).

[Isaurio]

You could also try resetting the computer. Disconnect the battery for 15 min and reconnect, let engine idle for 15 min, drive the car for a few miles so it would relearn some sensor values.

[oakrdrs187]

Im suprised Ronnie didn't school on tranny flushes.

I would also look for loose vacuum lines and the intake for loose clamps.

[onprcntr]

So the wife drove it and it shuddered and the "service engine light" came back on. The code showed a miss on #1 cylinder. I checked the battery at that point and the neg. terminal was crudded up real bad so I cleaned that up. The only problem I'm having now is a periodic rough/low idle. Car pulls well and still gets good mileage and uses no oil. I hope its not the damn IAC.

[Isaurio]

If you have a miss fire in one cylinder is a good start. One, this is maybe do to a ignition problem such as, spark plug or wire. Double check all your spark plugs and wires make sure is no oil leaking in the spark plugs. Double check the injector plugs. 128K I will clean the MAF with maf cleaner, and cleaning the TB with carb cleaner. Good luck and let us know.

[stonent]

The coils went out on my wife's 2002 around that mileage and started getting random misfires.

Try swapping the coils and see if the problem moves to another cylinder.

[M-Rod]

I would also check the intake manifold at the throttle body flange. unmetered air could cause a rough issue.

[Isaurio]

I would also check the intake manifold at the throttle body flange. unmetered air could cause a rough issue.

yeah, but that will cause random miss fire not just one cylinder is effected.

[Hevymetalg]

Change the valve cover gasket,you plug is prolly fouled out with oil finding it way in there. It's cheap and easy.

[onprcntr]

while checking the plugs I noticed two of the sockets that they are in were full of oil. I replaced the valve cover gasket, the round seals by the plugs and I put new plugs in. I also replaced the PCV valve. In the last month in addition to this I've changed the air cleaner the oil and coolant and also the o2 sensor. It seems to be running better now than it has in a while. I hope this was why I was having the issue. It seems like every time I work on it it runs better for a day or two then starts acting stupid again.

[tamim13]

Check the coil packs as mentioned earlier by stonent, that's usually the culprit in our cars. They tend to go bad. It's an easier enough check.

[onprcntr]

Thanks for all the suggestions. At this point she's running better than she has in years. No more miss no more CEL so I'm going to monitor a while and make sure there are no other problems. Im sure that the pools of oil in the spark plug tubes was the culprit this time.

[oakrdrs187]

Well there you have it folks, proof that maintenance goes a long way.