Rough idle 08 ve v6

[Jake96]

just wondering if it's normal that my 2008 v6 ve has a rough idle? What could I do to help? No engine codes coming up, run 95 or 98 in it, have tried injector cleaner didn't help car only has 129000ks. Any ideas on what could help or is just normal?

 

[UnmedicatedLunatic]

It's all witchcraft under the hood these days, if the car just idles rough all teh time or fluctuates it could be crappy plug wires, distributor, rotor, failing O2 sensor or even a sticking idle stabilizer valve - to name a few. If it only idles rough when it's cold, it could be a problem with the engine temperature sensor. As the engine temperature sensor starts to fail, it can start sending false (higher) readings to the control unit which would lean out the fuel mixture thinking the engine is operating at normal temperature (ergo not throwing an error code). As the engine warms does it start running smoother?

 

[Jake96]

Seems to be only be rough on idle when the engine is warmed up sitting at sets of lights. Starts fine and cold starts for a couple of minutes on 1000rpm all normal then drops down to 550rpm like normal. I was thinking it might just be spark plugs? What should I start with changing first?

 

[UnmedicatedLunatic]

Sounds like a good place to start. No need to replace them yet, just check for fouling and clearances - if they look fine then they probably are. While you're there, check your plug wires and make sure they're not brittle or damaged. Let us know how it goes and we'll keep troubleshooting.