weird and really rough idle: Problem Solved

[JMRQuattro]

I searched thinking it might be my coil packs, but a lot of the rough idles i've come across seem a lot different from description.

But... for about the last week i've had a problem with my car's idle. It starts just fine, no problems there, but when i get it started the car shakes a lot and idles pretty low. And i tried to drive while this was happening and the car has pretty much zero power and when i give it gas it's like i can hear the cylinders going "thunk, thunk, thunk, thunk". And the higher i rev the faster the thunking gets and the more violently the car shakes, but the car really doesn't feel like it wants to move any faster.

It only happens on cold starts, and i've figured out that when this happens i can pretty much get it to go away immediately by doing the following:

I start the car and it idles like hell and i get a blinking CEL that then stops blinking and stays on after about 5 blinks. Then i just give it gas, while in neutral, and rev up to about 3k rpm's and hold it for about 5 seconds, let it off and it's gone . If i rev too quickly, the car starts to feel like it's sputtering and shakes and it doesn't work, so i've figured out i have to rev it up to 3k very very slowly in order to prevent that. Also, once the rough idle goes away i can start to drive just fine, but when getting up to speed for the first time i still get random little sputters at certain rpm's while changing through gears until about 4th gear, but this is only on the initial start. Once i slow back down and get up to speed again nothing happens.

I'm guessing this is multiple cylinder misfires or something? I don't have a VAG-COM so i can't figure out my code without going to schucks, and yes i know some of you will say "go to schucks", but i haven't had time as i've been dealing with the death of my cousin in colorado.

The other thing is that when i bought the car all four coil packs were new, so i don't understand why it would be the coil packs unless they are huge pieces of shit.

Any ideas to help guys?

[A4p]

Dont know why, but you sayin that the coilpack are new, have you looked at the sparkplugs bc you know cp holding sparkplug, they connected eachother maybe somehow that could be the problem... just a thougt

[[email protected]]

Is there any smoke coming out of the tailpipes on cold start?

Check your coilpacks then your sparkplugs.

If they both look good then with the sparkplug out peer into the chamber with a flashlight and look at the top of the piston head and see if there is carbon buildup on it or not.

[JMRQuattro]

^^ i'm not really sure about the smoke on cold start. Yes there is, but it's just because it's been about 35 degrees out lately that i'm not sure if it's because of the weather. Although there is a very strong exhaust odor on cold starts that eventually goes away.

I'll check out the spark plugs, and if it ends up being the coilpacks i'm definitely going with a different brand.

[favianjanitra]

Winston, what would you recommend to use to clean the carbon build up?

Techron? I can see some carbon deposits on mine

[a4_boi]

I had the same issue 2 weeks ago. Go check CP. I blew 3 at once. :(

[wolfdog]

I'm going to ask anyway - coil packs were new when you bought the car but how long ago was that in years and miles? Sounds like a spark problem to me and that's usually a CP then plug issue (plugs in too cold a range? i.e. BKR7E instead of BKR6E?)

[[email protected]]

Winston, what would you recommend to use to clean the carbon build up?

Techron? I can see some carbon deposits on mine

You got it wrong. You want to see carbon on the domes.

If you don't that means something is getting into the chamber to steam clean it. In my case it was coolant which was leaking from a crack in the head.

The car would startup and act just as described by the OP, when the car was on it would drive fine and have the odd stumble at idle when hot.

[JMRQuattro]

I'm going to ask anyway - coil packs were new when you bought the car but how long ago was that in years and miles?

I bought the car with 86k miles, and it currently has 87,879 miles. And it was about a month ago that i bought it.

[JMRQuattro]

Problem solved. I finally went to schucks to read the code, and the code i was getting was cylinder 2 misfire. And it was just the spark plug. The cylinder 2 spark plug looked like complete shit but all the coilpacks were good just like i thought. So i changed all 4 of the spark plugs out for the NGK BKR6E V-Power plugs and no more rough idle and no more sputtering. I also would like to add to the review on these plugs. I noticed an immediate difference in the feel of the car all together. Response was much quicker and power was surprisingly quick to come on and stayed throughout, as opposed to with my old ones where i was able to tell when the power would start to go away and it would bog down quite a bit more. The car starts instantly and is very smooth at idle as well. It's even smoother than it was before, even from before i started having the rough idle problem. Great part and pretty cheap. It was about 7 bucks for all 4.

[R3K8C24]

^nice glad u found the problem.

Where did u buy the spark plugs?

[JMRQuattro]

^^ i got them at schucks, last 4 they had in stock! And i'm glad it's fixed too, so much better. And it'll be nice for the cold mountain pass.

[Turb_Oh_A4]

It's deffinatly funny to hear of the different stores everyone has in their part of Town. Like your Grocery stores and what not.

[ApexIt]

sounds like you bought some copper sparks. Dont forget that they have a shorter life span, usually around 5k miles

[JMRQuattro]

^^ judging on what i experienced from this time around, i'm sure i won't forget

[[email protected]]

I change the copper plugs out every second oil change

[A4natomical]

I change the copper plugs out every second oil change

same

[wolfdog]

Hope you checked the gap to confirm before install. Glad you solved it!

[JMRQuattro]

yeah i checked them all before i put them in. They were all the same and were at .32.