Engine 'hiccup' at 2750k rpms.

[irongrey]

I have an 09 CC, 2.0T, MT with about 48k, APR stage I and Carbonio.

I have had this annoying engine hiccup right at 2750k where the power delivery is not smooth. It is like a brief pause and drop in power as the engine revs, followed by a resumption of smooth power. It only happens at 2750k and is most noticeable in 2nd gear, though I can feel it in other gears as well. It only happens under partial throttle. With anything approaching heavy acceleration, it does not happen.

It still happens in stock, but less noticeable.

At 39k I had the intake manifold and all injectors and plugs replaced along with a carbon clean. I had the hiccup before that work was done and still have it afterwards. No CELs with this.

Any ideas? Does anyone else have anything like this?

[feesh]

I'm experiencing this same issue right now with my 2010 GTI at 65k. Slight hesitation under partial load at around 2200 and again around 2750-2800 rpms. Most noticable in 2nd gear and not noticable under greater load. Also seems to be accompanied by poorer gas mileage (mid single digits as displayed on the MFD) when accelerating in those low load conditions in gears 1/2/3. No CEL's as of yet.

Edit: I also had a P2015 code a while back, cleared it, and asked dealer about intake manifold. They said it wasn't covered under warranty so I didn't have them look into it as they wanted $80 to look at it. Didn't document. Does the P2015 code affect performance at all? On the TSB I've seen it says *does not affect performance*

[irongrey]

I'm experiencing this same issue right now with my 2010 GTI at 65k. Slight hesitation under partial load at around 2200 and again around 2750-2800 rpms. Most noticable in 2nd gear and not noticable under greater load. Also seems to be accompanied by poorer gas mileage (mid single digits as displayed on the MFD) when accelerating in those low load conditions in gears 1/2/3. No CEL's as of yet.

Sounds identical to my issue, except you have two hiccups (yikes). When did yours start? Are you able to reproduce it reliably?

I have not noticed lowered gas mileage during the hiccup (is that what you meant?). I did experience lower mpgs for quite some time (by 10 to 15%) but that was fixed when they replaced my intake manifold. For the longest time, I thought it was my new tires, but I guess not.

Anybody have any ideas what the issue could be? (it ain't the injectors, plugs, or intake manifold). A sticky valve? What does it mean that it is at such a specific rpm?

[feesh]

Yikes, I must have a bad intake manifold then. My gas mileage is just plain poor unless i'm on the freeway - at least 10-15% worse in town than it used to be. Freeway mileage seems to be less of a noticable difference. That's what i meant by poor mileage, it's just poor all the time in gears 1/2/3 around town, even in low load. Not just during the hiccup/s. I figured since the P2015 code hadn't come back after it was cleared that it wasn't an issue any longer.

I guess I'll have to take it in and try to get the dealer to fix it under warranty. Hopefully they acknowledge the fact that I asked them about it before my drivetrain warranty expired.

I can reproduce it pretty reliably, like I said mainly in 2nd gear under light pedal pressure/acceleration as the tach sweeps by 2750 I can feel a slight pause and then surge to 2950/3000 rpm.

[ViRtUaLheretic]

try changing your coilpacks, my car felt much smoother, plus I wasnt able to recently get higher than 26mpg but now that I swapped my coilpacks I was able to hit 29mpg omw to work this morning.

[irongrey]

FYI: My very long-standing engine hiccup turned out to be frequent misfires in two cylinders due to marginal coil packs. Apparently, the misfires were not bad enough to register a CEL. The mechanic also told me there is a recall out on the VW coil packs I had in my car.

And as I suspected, the dealership was totally incompetent as I had the car there like 5 times over a couple years for my hiccup issue and they never tried changing the coil packs, they never found the misfires, and they didn't tell me about the recall. What the hell??? The mechanic I took the car to found the problem immediately.

[Elcroato]

What's the PN on the recalled coil packs?

[siren001]

What was your city mileage, Im trying to figure out why I only get 240-260 on 13galons with mostly city driving.

[irongrey]

What's the PN on the recalled coil packs?

There are many numbers. Can you give me an idea of what the number would look like, how many digits?

[irongrey]

What was your city mileage, Im trying to figure out why I only get 240-260 on 13galons with mostly city driving.

My mileage was fine, though I did have a period of decreased mpgs in the months before my intake manifold went out.

[siren001]

any signs your intake manifold was on its way out?


So far i've got waterpump, throttle position sensor, Fan and shroud

[bordercitymadman]

Totally not wanting to thread jack, but what IS the latest revision for these blasted coil packs? can you use coil packs for a 2.0T that are for a different model as long as they are for a 2.0T?

[irongrey]

What's the PN on the recalled coil packs?

The new coil packs have the following P/N: 06H 905 115.

Actually, that is the same number as the old ones too.

[Rangod]

my 2010 gti and my 2012 cc with cbfa engines did this gti with tune and without and cc never tuned.. you will notice the engine "rattle" goes away when smooth engine running returns. i suspect the chain tensioner sucks causing out of time camshafts on the exhaust side (not moni-turd, and not a misspelling) until oil pressure builds up enough. there is an issue with the chain tensioners failing and causing head and piston damage. i traded in mine. good luck

[feesh]

Well, finally got another check engine light the other day. Took it in and diagnosed as the dreaded carbon build up. $900 for the scrub service. I'm also going to have the intake manifold replaced as well.

[irongrey]

Well, finally got another check engine light the other day. Took it in and diagnosed as the dreaded carbon build up. $900 for the scrub service. I'm also going to have the intake manifold replaced as well.

Do you know what the code was?

$900 for carbon clean. ouch.

Let us know if it resolves your problems.

[feesh]

I didn't get the code, but they took it for a drive and said the readings they were getting from their diagnostic tool plus the code plus my mileage were indicative of carbon build up. I'll get the code from then when I take it in next week and I'm also going to request that they take pictures of the process. For $900 I want to see that it gets clean.

I also tried contacting VW customer care to see if they'd be willing to provide any monetary assistance since I'm barely out of warranty and they basically said "we've never heard of carbon build up" and said good day. Maybe the dealer will fight a little for me (I won't be holding my breath). I hope the current class action lawsuits I've read are in progress result in extended warranties/services for current owners of these engines. This is a serious design flaw and VW is aware of it as is obvious by their next TSI engine which comes with both port and direct injection.

[irongrey]

Not to be redundant (as I am also posting this on the CC forum), but FYI: after one week of smooth driving, my engine hiccup is back. Ugh. This is pretty much how it went after getting my intake manifold and injectors replaced - smooth for a week or so and then slowly it comes back.

I drove it in stock for a while and could still detect a very slight lack of smoothness at 2700 rpms so I guess the tune is just bringing out into the open some underlying, marginal issue.

At least now I know the hiccup is from misfires. But why???

I am fairly certain that I have noticed that it gets worse in warmer weather.

Back to the shop next week. I wonder what I will get replaced this time?