My car is idling terribly

[Jdking463]

https://www.dropbox.com/s/khkry5wz2k...%20PM.mov?dl=0

2006 Saturn Vue
2.2 engine
Manual transmission

So as you hear in the video the engine sounds very bad
It only does this through idling though
When you start driving the little metallic noise still remains though. Maybe a belt issue?
Everything else is fine while the rpms are around 1500 or so
Idling is the major issue. Sometimes the rpms will drop tremendously and the car will shake a lot and it almost stalls but still has yet to do that
I've recently gotten a full synthetic oil change last week and I've had the spark plugs themselves changed
Could this be caused by the spark plug wires? Throttle body? I'm not much of a car guy so I'd like to hear your personal opinion on what you think it might be. Thank you!

[Phillb]

Can't be sure from the video but it's possible that your timing chain tensioner didn't like the oil you put in it or it has just failed so it could throw your timing out at idle but once you introduce load on it it could tension the chain again. If you give it a rev does it rattle more between acceleration and deceleration? And is it quiet on acceleration (whilst stationary)

[shorod]

It sounds very periodic and since you just had the spark plugs changed, the first place I'd look to is the spark plugs and spark plug wires. It sounds like an ignition misfire more than something less-likely to be periodic such as a vacuum leak.

Were the spark plugs installed to attempt to fix this, or did it start shortly after the plugs were installed? If the spark plug wires were reused, there's a good chance they are bad. You could carefully pull one spark plug wire at a time to see if there is one that has no effect on the way the engine runs. If so, you've at least narrowed the issue down to something related to a particular cylinder.

Is the spark plug wires look fine, then you may want to pull the plug associated with the bad cylinder (assuming you try narrowing it down to a single cylinder) and carefully inspect the spark plug for things such as a crack in the porcelain.

I have also helped a co-worker with a Saturn (years ago) that had a bad misfire which turned out to be a faulty fuel injector. So that's one other thing to consider if you are able to determine the misfire is not due to a spark plug or spark plug wire.

-Rod

[Phillb]

If it is a missfire you would usually still have one at 1500rpm and when you accelerate quickly under load it should miss fire still if it's a weak spark due to an introduction of more fuel which will help to extinguish the spark hence engines with weak spark will flood. If you are going to pull off the HT leads then use a lead light with the bulb removed at the end of the HT lead connected to the battery negative to divert the electric safely to the battery. Pulling leads off is an old technique to check for a miss fire but it will allow 10,000v to pass through the engine which has numerous 5v sensors and 12v actuators it's not really recommended any more but it will still work if you don't have tools like an occiliscope to test components but this will help to identify if you have a miss fire from 1 cylinder. You would get a crack from a weak spark and injectors will make noise but if you can get to the fuel injectors easily you can unplug 1 at a time it will give the same result in testing as pulling ht leads but you won't be throwing unburnt fuel down into the catalytic converter and damaging it if you can get to the injectors. I have had a timing chain tensioner fail before when an apprentice put the wrong oil grade in the car

[Nnaemeka]

this coud be a belt or bearing issue...however there various other issues that could lead to bad vehicle idling.