# Rumbling/vibration around 2k rpm on '14 Passat manual with 93 octane tune



## wwoebke (Aug 21, 2014)

Just fishing around to see if anyone experiences an audible rumbling with vibration at the front/mid of vehicle under specific circumstances. Disclosure: former OEM auto manufacturer powertrain guy here. Trying to figure this out, not start flame war 

*93 octane tune (high torque at low rpm)
*barely perceptible in 3rd, but more in 4th and very much in 5th
*about 1700-2200 rpm ONLY when deep into boost - as soon as I even slightly reduce torque, it goes away
*seems to be related to engine firing frequency (i.e., 2000 rpm = 66Hz firing frequency...still audible and tactile at same time)
*not related to road speed
*sweeping through problem area in 1st or 2nd goes too fast to develop the rumble.

Hypotheses:
*half shaft shake (torque related dynamic runout)
*engine mount/trans mount groundout from torque reaction
*exhaust system ground out due to torque reaction.

It doesn't feel like a misfire, not slipping clutch.

So...ideas? I would HATE to have to get a 91 octane tune or just avoid the sweet torque at 2k!

Thanks!


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## JoeGLI (Feb 7, 2011)

I have a tuned 2014 Jetta SE 1.8t and have the EXACT same issue, you described it perfectly. Haven't had much luch figuring it out either, its definately a load issue, I was thinking of trying a dog bone mount and seeing if it is the engine movement but usually that also comes with a wheel hop issue which I dont have. I contact the tune manufactuer and they said they have had no other reports of this with the tune so I went bact to the shop. The tech told me to just stay out of the gas at that RPM......Ok.

Definately a driveability issue, as you know with a 5 speed with wide gears you cant stay out of that normal driving range rpm. Hope we hear from more people so I can find a way to fix it and keep my tune!


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## Shawn99/30V (Sep 28, 2000)

Which chip do you have?


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## JoeGLI (Feb 7, 2011)

APR 93


Sent from my iPhone using Tapatalk


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## 65Strad (Jul 4, 2011)

JoeGLI said:


> APR 93
> 
> 
> Sent from my iPhone using Tapatalk


Maybe Arin has a thought/solution. If this is APR's chip/flash, what was their take on it? 

WWeobke, as an OEM powertrain guy, I'd say it's decent bet that you made that inquiry. If so please share the wisdom.


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## Shawn99/30V (Sep 28, 2000)

I wish APR has a chip designed to take the regular gas 87 octane like the factory engine. I am not greedy but I just wanted everything to perform without any issues.


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## tagsvags (Nov 25, 2005)

^^^ Why not just stay stock. ^^^


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## wwoebke (Aug 21, 2014)

I chatted with APR and gave them the description, so just awaiting some feedback. I don't really expect this to be a high priority for them.

Update on observations - in cold ambients, the rumble comes in sooner (like perhaps 1400 rpm) so I suspect it is either torque related (increased torque due to cooler temps) or some elastomer issue on a damper/mount (due to increase in stiffness/reduction in isolation at cold temps).

I can tolerate it in 4th gear but it is much harsher in 5th. That leads me to hypothesize it is some forced response or resonance through a mount which has greater time to build in amplitude in 5th gear vs lower gears...

On an unrelated note - just bought the ECS fog light kit and may have my local VW dealer install or Steve's European Auto in Waterford, MI install. Really looking forward to getting that done. Then, stage II with downpipe. Then air intake. Then......(money runs out)


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## Mbullick (Feb 23, 2016)

I just had the APR stage 1 91 octane tune installed on my 2016 Jetta sport 1.8t. I'm experiencing the exact same thing. 4 th gear is tolerable but in 5 th it's so bad I am afraid to accelerate past the vibration. Have you found a solution to this?



wwoebke said:


> I chatted with APR and gave them the description, so just awaiting some feedback. I don't really expect this to be a high priority for them.
> 
> Update on observations - in cold ambients, the rumble comes in sooner (like perhaps 1400 rpm) so I suspect it is either torque related (increased torque due to cooler temps) or some elastomer issue on a damper/mount (due to increase in stiffness/reduction in isolation at cold temps).
> 
> ...


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## V42 (Feb 25, 2008)

2015 Passat 1.8t manual trans. Just did APR stage 1 93, Getting the same noise / vibration in high gears under load.


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## DasCC (Feb 24, 2009)

Shawn99/30V said:


> I wish APR has a chip designed to take the regular gas 87 octane like the factory engine. I am not greedy but I just wanted everything to perform without any issues.


They do..... http://www.goapr.com/products/ecu_upgrade_18tsi_gen3_trans.html


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## V42 (Feb 25, 2008)

This is true. They have flashes available for 87, 91 and 93 octane.


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## Mbullick (Feb 23, 2016)

I was talking to wwoebke in PM's. Seems like this is common. He thinks its due to the engine cradle torsional stiffness. Not much we can do about it unless you want to significantly increase the overall NVH of the car. I am considering ordering an aluminum dogbone insert, will update this thread if i decide to install. I really don't want to compromise NVH in the cabin.

After a thousand miles or so I have learned to adjust my driving/shifting to the point that the vibration doesn't appear at all. I don't know how your passat responded but it was pretty damn scary the first time in my jetta, VERY harsh. 



V42 said:


> 2015 Passat 1.8t manual trans. Just did APR stage 1 93, Getting the same noise / vibration in high gears under load.


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## Dirtmvr (Feb 28, 2016)

It sounds to me like the computer is advancing the ignition timing too much, and you notice it more in the higher gears because the load is higher. I don't think it has anything to do with engine mounts etc.


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## wwoebke (Aug 21, 2014)

It has nothing to do with the ECU and ignition timing. It's best to not to speculate , particularly when you are not sure of what you are talking about. People look here for answers, not opinions. 

If you wish to chat further so I can explain myself, please PM me.


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## geoff508 (Apr 8, 2008)

'14 Jetta 1.8T with the APR 87 flash, have had this since day one of the tune...I have learned to stay out of the throttle or downshift at lower rpms...or 'ease' into the throttle from lower RPMs in 4th and 5th. Always assumed it had to do with load, not sure if it's hurting anything, but i've had the tune for over 12k miles with no other issues.


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## Mbullick (Feb 23, 2016)

I have invited APR to this thread, lets see if they have a response since this is obviously not an isolated thing. I tend to think wwoebke understands whats going on here, and if thats the case its just something we have to live with or flash back to stock.


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## [email protected] (Jul 29, 2008)

Sounds like Low RPM + Tall Gear + High Output = Lugging it out. You'll get vibration, noise, etc on pretty much any high output setup in this situation as it's harder on the driveline.


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## krxtp2 (Aug 27, 2003)

87 tune, manual transmission. Vibration occurs when accelerating in 5th gear at about 2100 rpm. Not exactly lugging an engine.


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## V42 (Feb 25, 2008)

I feel it's my dual mass flywheel coming apart.


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## wwoebke (Aug 21, 2014)

Unrelated to DMF. Tiptronic vehicles do it as well. Related to engine/trans and cradle mounting response to low rom/high torque input


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## wwoebke (Aug 21, 2014)

Unrelated to DMF. Tiptronic vehicles do it as well. Related to engine/trans and cradle mounting response to low rpm/high torque input


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## Tdi13golf (May 31, 2014)

It's exhaust drone feedback into the NVH of the car. Adding a stiff dogbbone will make it worse.

At 2000rpms in a 4cyl turbo the resonating frequency is right at 66hZ. This will rumble the car.


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## Didimow (Feb 18, 2016)

I have a 2015 jetta 1.8t 5 speed with the Neuspeed power module for the last 10,009 miles and this just started i don't think the ECU or module has anything to do with it. Since mine just started and I've had it for awhile.


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## chois (May 12, 2000)

My 14 Passat APR 93 car exhibits the same behavior.
Feels exactly like a harmonic vibration of some sort. Some might mistake it for a waste gate flutter.
If I were writing the tune, I would dial back load request/boost in high gear low rpm conditions.
But I would also fix the awful throttle calibration off idle...


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## Doctor Meat Does Housecalls (Aug 27, 2010)

Same here with my 14 Jetta running a Stage 1+ tune from 2014. 

Has always done it since the tune. 

Always chalked it up to being a higher output from stock against the tall-ass gears. 

I usually just drop a gear, and continue on.


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## chois (May 12, 2000)

Update -
As I expected I had to replace the clutch at 55k miles. I was getting clutch slip in 3rd-4th-5th gears if I ever asked for high torque on the highway. I went with the South Bend stage 2 daily setup. This has a single mass flywheel that replaces the OEM dual mass unit. Not super cheap, but good quality. Buying parts and having a good shop do the work (no time) adds up to about $1400.

Once they got the parts off the car, it turns out the stock flywheel had failed, and the two masses were just flopping back and forth. Now I know why it had an annoying lurch whenever I tried to idle slowly in a gear in heavy traffic.

*Also - now the low frequency rumble/flutter that it was producing under high load/low rpm conditions after the APR 93 tune is pretty much gone. There must have been some sort of resonance going on with the dual mass flywheel.*

The downside is that this flywheel weighs less, which might be nice in a more sporty car, or really any car if it were not for the horrible throttle pedal programming that has this dead spot initially and then a way to fast response, which makes you stall or over rev all too often. If I were a tuner writing a new program for one of these cars, I would never let it out the door without fixing the throttle response programming....

All in all, the clutch drives fine (throttle tuning aside - that was an issue anyhow). I'm digging the car more than ever, minus the ding that I put in the RR quarter my own dang self...


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