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Engine roughness

Old May 5, 2011 | 10:59 PM
  #1  
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Exclamation Engine roughness

Hello all,
A new problem has occurred and a little stumped as to what it is. The other day I noticed that there was a misfire feeling about the engine. Naturally I looked for the CEL light and nothing. I opened the hood to find the engine rocking like it is misfiring. I figured a 97 A4 1.8T with 169000 miles was probably having a coil pack fail. I got all new packs, installed them and no change. I inspected the plugs with no cracks, and all looking nice and clean burning as they should. Hope someone might have some ideas. Checked the air filter (K&N), and I figured if it was a fuel issue it would be all cylinders. Feels more like just one is missing. Any help would be appreciated! Thanks in advanced.

Keaton Stanko
 
Old May 5, 2011 | 11:15 PM
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Our Audi had some vacuum hose issues but mainly the EGR valve was bad...it would idle like it was misfiring..it would surge too. Over the years our Audi seemed sensitive to the emission system. It even would run rough when the catalytic converter had issues from a small oil leak that wept into it. I assume you have already checked for vacuum leaks including air leaks in the emission system. We have learned with our Audi to look where the problem shouldn't be. LOL.
 
Old May 6, 2011 | 09:24 AM
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Even if you have no CEL get it scanned for codes anyway. Usually on AEB engines the coil packs are pretty solid, the ICM will sometimes go bad and cause a misfire.
 
Old May 6, 2011 | 09:33 AM
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Originally Posted by Laura JS
Our Audi had some vacuum hose issues but mainly the EGR valve was bad
His engine doesn't have an EGR, although a vacuum leak is very possible.

I'd scan it for codes that might be stored anyway. Like McGovs said, the icm's like to crap out. And why not throw in some new plugs either way.
 
Old May 6, 2011 | 10:08 AM
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Ok I'll check the ICM....and I'll throw in some new plugs. I'll be calling NGK if these are bad only after 14k! I am also cleaning the air filter and the MAF just in case. Thanks for the help guys I'll let you know what I find
 
Old May 6, 2011 | 10:13 AM
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I didnt realize the plugs were that new, I wouldn't replace them then, just verify the proper gap of .032 for stock boost
 
Old May 6, 2011 | 04:34 PM
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Scan for codes before you start wasting money on parts.
 
Old May 7, 2011 | 10:16 PM
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OK so swapped plugs just in case, swapped ICM, and no change. Going to scan for codes tomorrow let you know if I find anything. Good news is the guy at the parts store is lettting me return this stuff!!
 
Old May 8, 2011 | 07:57 PM
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Scanned for codes and nothing, looked at the live data and everything is within limits. I am now stumped.....any ideas?
 
Old May 8, 2011 | 09:34 PM
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Vac leak but even that would throw a code... the engine almost always has codes even for the tiniest thing... maybe blew out your snub mount...
 

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