Ghost cylinder 2 misfire - 2012 Audi A4 2.0t

[Audiguy92]

Bought a used A4 PP 2.0T 6 Speed last year. About 2 months ago it started misfiring. I hooked it up to VCDS and it didn’t show any codes besides “Multiple cylinder misfire”. I checked cam phase and was at -5.7 degrees. I was also getting misfires across all cylinders, but number 2 was MUCH higher. After completing the timing chain job, new Bosch injectors, and carbon cleaning I am still at a misfire on cylinder 2 only. Compression is good 175-200 across all 4, leak down was less than 4%, (good). Any other ideas? Misfire goes away with RPM above 1,000.

I am leaning toward removing the head. But I really do not want to.

[apeck240]

Bought a used A4 PP 2.0T 6 Speed last year. About 2 months ago it started misfiring. I hooked it up to VCDS and it didn’t show any codes besides “Multiple cylinder misfire”. I checked cam phase and was at -5.7 degrees. I was also getting misfires across all cylinders, but number 2 was MUCH higher. After completing the timing chain job, new Bosch injectors, and carbon cleaning I am still at a misfire on cylinder 2 only. Compression is good 175-200 across all 4, leak down was less than 4%, (good). Any other ideas? Misfire goes away with RPM above 1,000.

I am leaning toward removing the head. But I really do not want to.

When mine did exactly the same thing, it was a blown up rocker and wrecked cam lobe

[Allowencer]

Bought a used A4 PP 2.0T 6 Speed last year. About 2 months ago it started misfiring. I hooked it up to VCDS and it didn’t show any codes besides “Multiple cylinder misfire”. I checked cam phase and was at -5.7 degrees. I was also getting misfires across all cylinders, but number 2 was MUCH higher. After completing the timing chain job, new Bosch injectors, and carbon cleaning I am still at a misfire on cylinder 2 only. Compression is good 175-200 across all 4, leak down was less than 4%, (good). Any other ideas? Misfire goes away with RPM above 1,000.

I am leaning toward removing the head. But I really do not want to.

I presume you've swapped plugs and moved coil packs between cylinders to see if it follows?



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[Audiguy92]

Yes, all new NGK R plugs gapped properly, all new VW\audi coils. And even swapped since install to verify.

[Audiguy92]

So, the engine was money shifted before I purchased the car. My Local shop said that they found the retaining clips for one of the rocker arms that detonated before. No damage on the cam though. Any more ideas?

[Theiceman]

So, the engine was money shifted before I purchased the car. My Local shop said that they found the retaining clips for one of the rocker arms that detonated before. No damage on the cam though. Any more ideas?

if it was money shifted id be taking another look at that top end. not saying they are not a good shop, but things can happen at high revs.

[Allowencer]

If it was a true money shift, I'd expect more damage. Could be a slight misshift and you might be lucky.

I'm with iceman, I'd replace all rockers and lifters for sure. Inspect both cams completely. All lobes and guides. The exhaust cam, make sure the lobe pairs can slide without interference. For the intake cam, I would be concerned on the stator inside the VVT adjuster.

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[Audiguy92]

I finally got it. One of the roller rockers was flat spotted. I have now spent $4,000+ chasing a $9 part
IMG_3852.jpg


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[Theiceman]

yeah thought it might be a top end issue. glad you got it sorted . i don't trust shops .. even ,"well regarded" ones

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[Allowencer]

VAG updated the rocker design too. I bought the newest revision for my new build. Could be the case here..?

I've be concerned with the cam's lobe condition above that rocker. In addition, check the other rockers. If you see similar wear, I'd be concerned with an oil delivery issue.

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