Surging under mild acceleration

[Stubek]

This started about 2 months ago. When using less than 50% throttle to accelerate and above 2,000 RPM, I get a surging with a frequency of about half a second. Basically it will accelerate normal then add what the butt dyno says is about 5% then back to normal, then add 5%. You can see the tach moving and hear it too.

Mods on the car
APR state 2 tune
034 HFC
AWE Gen 2 Exhaust

Haven't really started trouble shooting this yet, wanted to see if anyone had suggestions or experience with this.

[blbroo]

Does this happen in all gears, or just the higher ones? Sounds like it's not under full boost?

[AllroadCorbin]

This used to happen with my APR Stage 1 tune. My stage 2 doesn't do this BUT (and this may sound stupid) make sure youre not in "Stock" mode. APRs "Stock" mode isn't stock at all and so its easy to think your in stage 2 under light driving conditions. But my stock mode has a boost surge just like you described. When I first got stage 2 I was pissed because it had the same surging issue as stage 1... I found out I was in stock mode and it went away

[shaunm82]

This started about 2 months ago. When using less than 50% throttle to accelerate and above 2,000 RPM, I get a surging with a frequency of about half a second. Basically it will accelerate normal then add what the butt dyno says is about 5% then back to normal, then add 5%. You can see the tach moving and hear it too.

Mods on the car
APR state 2 tune
034 HFC
AWE Gen 2 Exhaust

Haven't really started trouble shooting this yet, wanted to see if anyone had suggestions or experience with this.

I've experienced this as well. Usually always when on the freeway when cruising and I just want to pass someone and I apply a light throttle. But around 2k rpms it almost feels like a pulsating surge.

I emailed APR Support in Dec, they suggested to double check my plugs, and then get in touch with a dealer so logs can be done, and see if I can't duplicate the issue..which I think might be difficult.

Haven't had a chance to do that yet. Plugs are fine though.

[Stubek]

This used to happen with my APR Stage 1 tune. My stage 2 doesn't do this BUT (and this may sound stupid) make sure youre not in "Stock" mode. APRs "Stock" mode isn't stock at all and so its easy to think your in stage 2 under light driving conditions. But my stock mode has a boost surge just like you described. When I first got stage 2 I was pissed because it had the same surging issue as stage 1... I found out I was in stock mode and it went away

Definitely not in stock mode, I checked that first.

I've experienced this as well. Usually always when on the freeway when cruising and I just want to pass someone and I apply a light throttle. But around 2k rpms it almost feels like a pulsating surge.

I emailed APR Support in Dec, they suggested to double check my plugs, and then get in touch with a dealer so logs can be done, and see if I can't duplicate the issue..which I think might be difficult.

Haven't had a chance to do that yet. Plugs are fine though.

I'll see if I can do some logs in the next few weeks, got a cable, got a boost gauge, no need for a stealer to get involved yet. I wonder if they have an update to the software also.

[shaunm82]

Definitely not in stock mode, I checked that first.



I'll see if I can do some logs in the next few weeks, got a cable, got a boost gauge, no need for a stealer to get involved yet. I wonder if they have an update to the software also.

I'll see if I can get some done also. And by dealer, I meant an APR dealer, sorry~

Let me know if you find anything out, and I'll do the same.

[blbroo]

doesn't happen under hard throttle and heavy boost?

[shaunm82]

doesn't happen under hard throttle and heavy boost?

Mine doesn't. Only partial/light throttle that I've noticed.

[Rock803]

I have a similar issue. APR stage 1. A surging in only 1st and 2nd gear, around 2500-3000 RPM's. Hard throttle and it goes away in the same range. I've had it occur with afe filter, inlet hose, silicone hoses, r8 coils, gfb+, 3.0tdi intercooler and then with only the tune and r8 coils. Plugs are fine.

The Edge

[2010b8a4apr2]

unfortunately almost all vw/audi turbo cars do it. but if youre having boost issues and are under a specific mileage, look into vw/audi's wastegate issue

[Rock803]

Wastegate rod is tight. It started, in my case, about 3 months after the tune. Warranty is up.

The Edge

[Homer_J]

I'm not as informed as you guys, so TIFWIW. But I had surging at light throttle in my stock 2.0T. Usually it'd be driving around 50mph and starting to go up a slight hill that i'd notice it most. It felt to me like it was boost pressure surging, but if I put the transmission into manual mode, it would stop. Some threads I looked at mentioned the torque converter acting up, changing the transmission filter etc. But the revs would rise and fall slightly, as if it was a turbo issue. I'd be interested to see what your boost pressures look like. My problem went away on its own after about 6 months, [knock on wood].

Anyway, just throwing in the transmission as being a possibility. (assuming you have the auto)

[Jaydog0910]

On update on the culprit? I have a similar issue that started the day I got my apr stage 2 done. It happens both on auto and when I'm using tiptronic so I don't think it's a transmission problem. It happens to me when the peddle is about 50%. Thanks

[Jacon]

CVT?

[Jaydog0910]

CVT?

No, it has quattro

[richardm0025]

Same issue I'm having with apr stage 2. When I had to the tune removed (warranty purposes) did not have the problem at all...


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[blbroo]

Sounds like a software issue, for sure. Might be worth seeing what happens with trial file from another tuner. Or, try lowering your plug gap by at least 0.002, making sure you are, at least, the equivalent cold of an NGK 7 plug.

[Stubek]

Got it into stock mode and it took a long time, but I think I can reproduce it in stock mode even.

[audigraph]

I had a similar issue on my wife's 2012 A4. Completely bone stock quattro automatic 2.0T. It's a CPO so dealer checked it out and found misfire codes. They tested injectors, one leaked so they replaced all four and called it good. Went to pick it up and just sitting idling in the dealer's lot, the car started to rough idle and had zero power when I went to move it in the lot. Went back in, demanded they keep it. Sure enough a few days later I get a call from the service manager apologizing because what I told them it probably was (coils, thanks to the forum) is exactly what it was.

So for $85 CPO deductible and some shoddy Audi diagnostics, I got four new injectors and four new coils at 45k miles.

Just food for thought. I know throwing tunes into the mix is an entirely different ballgame, but figured I'd chime in with my latest experience.

[jorte014]

Have this exact same problem as well, car is at 75k miles and it's been doing it ever since 55k miles. I replaced coil packs and plugs at 70k and it did not resolve it. My shop suggested I send logs to APR but I haven't followed through since it only happens for an extremely narrow spot on the RPM range (2850 - 2950 rpms in my case as far as I can tell) and only with a very specific application of the throttle. It HAS to be a software problem because I used to have the old APR Stage 2 tune and did not have any issues and then I got the software update to the new version last year and it started doing this surging. Just goes to show how different each ECU firmware is for the same model car throughout it's generation, hard to account for every single case.

[blbroo]

Have this exact same problem as well, car is at 75k miles and it's been doing it ever since 55k miles. I replaced coil packs and plugs at 70k and it did not resolve it. My shop suggested I send logs to APR but I haven't followed through since it only happens for an extremely narrow spot on the RPM range (2850 - 2950 rpms in my case as far as I can tell) and only with a very specific application of the throttle. It HAS to be a software problem because I used to have the old APR Stage 2 tune and did not have any issues and then I got the software update to the new version last year and it started doing this surging. Just goes to show how different each ECU firmware is for the same model car throughout it's generation, hard to account for every single case.

Have you reached out to APR for help? I give them a hard time occasionally, but have heard that they handle one on one service pretty well. You can send them logs with the mobile app, right?

[jorte014]

Have you reached out to APR for help? I give them a hard time occasionally, but have heard that they handle one on one service pretty well. You can send them logs with the mobile app, right?

Yes, they suggested I send them logs with the mobile app, just didn't feel like buying a mobile dongle. It's on my to-do list.

[Stubek]

I've been in stock mode for about 10 days (but in Hawaii not driving for 7 of them) and only got it to do it once. I am doing a couple hours of highway driving tonight which is when I normally get it to do it so I think if I get it to do it tonight, then it is not APR.
Also, not really sure how it can be APR as this is a new issue in the last 4 months for me, but I have had APR on the car for a year since my last service.

[Jaydog0910]

This sounds similar to my issue. The same symptoms for the past month or so, then it happened to me one time and the CEL flashed while it was happening then turned off. So of course I tried it again after a couple of minutes, the CEL flashed but then stayed on. I read the error and it was a misfire in cyl 4. Called the shop, they said it's common that the coils need to be changed after you put the extra pressure of stage 2 on the car. Imy getting them changed next Tuesday to the r8 coil pack. Hopefully that works. I got some other advice saying it may be PCV, but my car passes the oil cap pressure test, so I "think" my PCV is fine.

BTW - I notice the issue much more frequently if the engine is hot and I've driven a far distance, like an hour. It doesn't seem to happen as much in a 10 minute drive. Have you noticed anything similar?

[kdaffy]

any update on this...i randomly get something similar, going up a hill, narrow rev band (2700-2900 rpms)...happens maybe once a month or so for the past few months since i went stage 2 (APR)

[TJet1.8]

Yep...same problem here with APR Stg 2, R8 Coils, Plugs gapped to .028, AFE Air Filter, etc...(see my sig)....AND...6MT.
Also started happening 3-4 months after I got the APR tune.
Strange...

[blbroo]

Have you guys tried NGK 8 range plugs? @allroadcorbin moved to them and it helped his issue a lot.

[AllroadCorbin]

Plugs helped and honestly even though I've only limped my car back and forth between body shops lately... The big TR11 fmic makes power noticeably less hesitant. Keeping things cool in your engine is really key. If you are at 70k miles or more, get a walnut blast carbon cleaning too


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[kdaffy]

I did carbon cleaning @ 69k, new plugs (NGK BKR7EIX, but had NGK PFR7S8EG as well and this happened) and R8 coils about 1.5k miles ago, and im running the 3.0 TDI IC. I can rule out the IC since I had this issue when the weather was not hot, not sure if i need to swap plugs again.

[Stubek]

Update:
I put the car in stock mode for a few weeks, maybe a month. Barely noticed this happening, maybe once or twice. I went back to stage 2 about a week ago and haven't felt it since then.
Quite odd.

[Brandon K.]

Went from APR stage 1 to stage 2. It did not show up initially (1st 1000 miles). About a month after install, did ECS red coils and cooler plugs. It has been 5 days and it has happened twice. It is definitely software related, but it appears to happen in conjunction with coils/plugs.

If I swap the plugs & it stops, I will let you know. Not sure when I am going to do that.

[Brandon K.]

The surging had continued to increase and become more annoying. Swapping out the plugs to the old ones reduced it dramatically but it is still there. I may try disconnecting the battery to reset the adaptation to see if that fixes it before going back to the old coils.

The old plugs have seen better days and should probably be replaced, but they work better than the new ones...


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[Party_Marty]

Yea I have this issue too. I figured it was all software related. It feels like since the turbo is allowed to spool higher under WOT then partial throttle sends it shooting up in pressure even when you don't want it. I get the surging twice in my RPM range and frankly its annoying, esp when i'm driving with friends and just cruising and the car surges under little acceleration and jerks back when the pressure normalizes. I'm just like wtfffff. This makes me think...this is in no way a big turbo, but would a boost controller help this? Anybody have any input?

[Brandon K.]

I did a little driving with a Foxwell scanner hocked up. According to it, the boost pressure was not fluctuating in conjecture with the surging. Although the Foxwell refresh rate seems too slow to be trustworthy.

I have not disconnected the battery yet to wipe the adaptation. Does anybody know if switching from one APR tune to another (exp. stock, 91, 93 octane) resets The adaptation? I have noticed it feels like it does.


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[kdaffy]

Anyone from Apr want to chime in? Arin?

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[Brandon K.]

+1


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[Arin@APR]

If something seems off, shoot our support team an email: [email protected]

[TVP125]

My B8 does the exact same things as a few of you guys describe right around 3K RPMS. I'm Frankenturbo with Eurodyne.

[Alex1188]

It has to do with the phase of where the Intake manifold flaps open and close. The change in intake air velocity is what your feeling. The flapper actuator is vacuum driven and isn't very accurate. The reason your not noticing it on stock tuning is the way the map is designed from the factory is a lot more linear than all the aftermarket tuning is. Boost ramp is completely different. Also I believe company's like APR don't touch that part of the map, hence why they don't offer a flapper less tune for our cars. Correct me if I'm wrong Arin@APR.

[Brandon K.]

APR had asked me to log data for them to analyze. Does anybody in the Vancouver Washington area have a VCDS or similar? They have requested 12 fields be lodged. I have an ECS handheld scanner, but that is not adequate for this.


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