GenVibe - Community for Pontiac Vibe Enthusiasts

Hello,

2005 Vibe with 133,000 miles. Changed the plugs and noticed the spark plug and boot #1 (#1 being the far left when standing at the front of the vehicle looking at the engine) had oil on them.

Changed the vale cover gasket to address the oil issue. Used Denso iridium plugs (original were NGK). Also, changed the air filter.

Started the vehicle up and all seemed well. No oil leaks. Idle then became rough. Vehicle feels like it is about to stall out, but does not. Engine appears to slightly shake. No CEL at present.

Thought is might be a ignition coil going bad (maybe the one that oil on it). Pulled the electrical connector at each ignition coil. Each time the vehicle almost stalled out - which leads me to believe the coils are all working.

Thoughts? I thought about buying a coil and switching it out with each one to see if the engine runs any better. My thought is that maybe one of the coils is going bad, but not bad enough to cause a misfire yet. Also, thought about cleaning the MAF.

Any help or suggestions are greatly appreciated. I do a lot of driving for work and would prefer not to become stranded.

Thanks,

Dante

In my original post, I forgot to mention that my neighbor (who is very mechanically inclined) came over while I was changing the plugs. He smelled gas on the plugs and believes the injectors are probably leaking. He stated that eventually this will cause trouble starting the vehicle, and they will have to be replaced. I am not sure if this "injector issue" has anything to do with the rough idle. If so, it seems odd that they just started really acting up once the plugs and air filter were changed.

Thanks,

Dante

I would think new plugs should fire easier than old ones so they would put less load on the coils. Did you inspect each of the new plugs and verify the gaps before putting them in? Its possible one of the new plugs is bad as well. I'd try switching in an old plug one at a time before getting a new coil.

Thanks for the suggestion. None of the plugs needed to be gapped, but I did check them all prior to installing them.

The coil pack is $100 or so. Like you said, it might be worthwhile to install the old plugs and see if the idle improves. I also agree that the new plugs should make the engine work "less" so, it does not make sense that the engine is running rougher.

I also thought about adding a fuel "cleaner" (like Techron) to see if this helps at all.

I would try one old plug in each cylinder sequentially like you described for testing the coils. One of the new plugs may be bad and it may not be anything that will be visible by inspection.

Just to let you know, and I understand that it might not pertain to your situation, but I brought my car to my mechanic today and had him do a BG cleansing of my throttle body. At 75,000 miles, I had never had this done before. Over the past 5 months, I noticed that my RPMs were dancing between 1100 and 1600, especially after letting off the gas pedal and especially when the air conditioning was on. I also had instances of near stall outs when coming to a reasonably hard stop. I never stalled once, but I figured it was a build up of carbon. The car ran nicely on the ride home today, but I'll report more about whether it permanently fixed the "rough idle" as time goes by.

I had similar issues... removed the throttle body and cleaned it thoroughly as well as MAF sensor. Seems to help, if you had a leaky injector or plug issue... you would def know... these engines do idle a lil rough though regardless.

i would also recommend using the NGK iridiums... disconnect the battery for a bit to reset the PCM. These things have worked for me... got 211,500 mi and still going strong.