[gadams]

I own a 2008 3.6 liter 6 cylinder SRX with 112.000 miles. I have recently began to experience an intermittent misfire at idle and while driving after the engine warms up to normal operating temperature. The check engine light is not on and I do not have any fault codes. I changed all 6 coils and spark plugs and the vehicle still experiences the same issue. I'm a DIY and any help would be greatly appreciated. Thanks, GAdams

 

[08SRX]

How do you know you are having misfires if there are no codes? My understanding is that if there are misfires there should be codes telling you which cylinder is misfiring. Once you have come to a solid conclusion on the problem, misfires can be caused by anything from ECM to bad spark plug cables.

 

[gadams]

Intermittent poor idle and slight jerking while driving is what is leading me to believe it is a misfire. The vehicle runs and drives great until it warms up. That's what's perplexing to me.

 

[08SRX]

Carboned up throttle body? Poor gasoline? Cold weather - icing? Clogged fuel filter?

 

[glake89]

I would look at cleanliness of air intake between filter and TB, esp. for oil and then PCV system.

 

[gadams]

Great advice. Thanks everyone for your help!

 

[Tiger1106]

A scanner will tell you which cylinder is misfiring even before the codes light, look for real time scanning.

 

[The Wrench]

My '08 V6 has a very similar intermittent problem. Done it for a couple years; not very often, maybe a dozen times in two years. Don't notice it while driving, but it occurs when pulling up to a red light and idling; engine gets really rough, like it's running on 3-4 cylinders. As soon as I give it a little gas to drive away it clears right up, and is smooth as silk at the next light, and for the next 2-3 months. It runs absolutely perfect 99% of the time. No codes, and new plugs awhile back didn't stop it. Cleaning the throttle body blade and wiping the oily gunk out of the air inlet tube where the PCV hose comes in seemed to help, but recently I cleaned it all up, and it did it about a week later: so.....who knows. Happens so rarely I'm not chasing it too hard, but kinda curious; weird.

DG