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Discussion Starter #1
So after a second round of a really rough idle (as in misfiring) and blinking CEL on cool mornings, I took the car into the dealer yesterday. Based on my previous experiences with these symptoms, I was pretty sure I was having more coil pack issues (which have all been replaced already). It turns out that the coil packs are fine, but my engine is developing carbon deposits on the intake valves which are causing the rough idle at startup. (For reference, I've got a 2002 GLS 1.8T with just over 30K miles.)

My question for you guys is about their recommended solution. They cleaned the valves, but they're recommending that I switch to lower octane gas (I always use premium per the manual) and then use an additive/cleaner every other fill up. Is it just me or does that seem kind of ridiculous to have to drop $5+ worth of additives in every other tank of gas to keep the car running right?

I'm also wondering about the switch to mid-grade gasoline, mostly because the tech's advice goes directly contrary to VW's. I'm still in the process of sorting through the mountain of previous posts on this subject. Seems to be a very "opinionated" discussion so far...

Any thoughts on keeping the valves clean and/or VW's recommended solution would be appreciated.

Thanks,

Justin

Oh and I almost forgot - Westside VW deserves props for their help yesterday. They squeezed my car into their very full schedule and even sent me home with a couple extra bottles of fuel additive/cleaner.
 

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It actually ISN'T contrary to what VW has said as far as octane goes. It's just contrary to what is in your owner's manual. They have told us about 1400 times to recommend lower octane fuel in certain situations, though I doubt very seriously that in your particular case carbon or octane is the root issue anyway.

Anyway, did they flash your ECM for the cold start problem?
 

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Discussion Starter #3
I don't have the paperwork with me, but from what they told me, they checked the coilpacks and cleaned the deposits - no ECM flash.

As you mentioned, I'm wondering what the root cause is and what I can do to prevent future issues.
 

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Yep, definitely sounds like it needs an ECM reflash. Request an ECM reflash if it hasn't been done already. (Having the coil packs replaced doesn't automatically mean the ECM was reflashed.) If the stealership doesn't know what the ECM reflash is, tell them to look it up in one of their TSBs.
 

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anyone have that TSB handy? I've been fighting a cold start issue on the GF's for awhile, wonder if that might do the trick.
 

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Jblough389 said:
anyone have that TSB handy? I've been fighting a cold start issue on the GF's for awhile, wonder if that might do the trick.
What year is her car? I'll see if I can get the TSB. If I do, it'll be a hard copy/paper. And I don't have a scanner. Would you want me to mail it to you?
 

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Discussion Starter #9
I've got a coworker with a VAG-COM rig, so I'll have to see about getting him to check the ECM details. I'll have to cruise over to their website to figure out how to check that out.

In the meantime, I've filled up with Amoco mid-grade (90oct) and dumped in a can of the VW/Audi cleaner additive. From what you guys have seen, what are the odds this is a fuel issue versus an ECM issue?

Thanks for the replies...
 
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