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View Full Version : New RS5 - major engine shudder / shake / vibration at high RPMs



acitrano
10-23-2015, 04:13 PM
Hey guys - I posted this over on AudiWorld (http://www.audiworld.com/forums/audi-a5-s5-rs5-coupe-cabrio-125/new-rs5-major-engine-shudder-shake-vibration-high-rpms-2890758/), but it's a bit dead over there these days. I figured I'd ask all of you too....

My 2015 RS5, which is awesome, just passed 1,000 miles a couple days ago. Now that it was out of the "run-in" period (which I followed fairly well, although I made sure the engine experienced lots of "variety") I decided it would be fun to do some spirited driving that evening. Well, I was accelerating up a highway on-ramp at WOT, and got a nasty surprise in second gear at about 7500 RPM. At that moment I felt a very nasty shaking from the engine, along with what almost sounded like a stuttering. It was very noticeable - even GF in passenger seat was like "what the hell??" I was quite stunned and immediately laid off the throttle and upshifted to 3 to lighten the engine load. There was also quite a nasty burning smell.

It doesn't seem to happen in first at the same revs, but I only tried it once. I haven't tried it in other gears and don't plan to. However, if the car is in "N" and I bring it up to 7500 or so, I do get the same shaking and a milder version of the smell that I got when it happened under load.

No CEL or any other warnings.

Setting up for immediate service of course, and I don't plan on revving it that high again. But some thoughts from you guys would be helpful. Major bummer considering how new the car is - doesn't even have plates on it yet.

[BELOW, UPDATE AFTER SERVICE APPT TODAY]

Brought it in today (Beverly Hills Audi). "Shop foreman" came out, sat in car, revved it, said didn't seem odd to him.

Then I got in, took it to 7500 and held it there, and showed him how the car/engine shakes.

He said I was "hitting the rev limiter".

I said, "But the car red-lines at 8500 - so first of all why would it be rev-limiting at 7500? It's marketed specifically as a high-rev engine (the whole HDZ/HRC 'Audi High Rev Concept' stuff), and second of all, why would the rev limiter shake the engine/car like that? All my previous Audis (S4, S5, etc.) rev limit by simply lowering the throttle - not by making the driver think the engine is going to leap out of the hood."

He kept saying "well, 7500 is pretty high. The engine is really spinning at that level."

And I basically kept saying the same thing as above - #1 it's supposedly designed to handle it, it's marketed as being able to handle it, and #2 that doesn't seem like a very elegant way to rev limit. Besides, if I wanted a car that redlines at 7000 or whatever, I could have spent a lot less.

I kept asking him if he had another RS5 we could try it with to see if it shakes like that. He said he didn't have one in the shop they could do it with. I suggested trying it with the coupe they had in the showroom. That didn't happen... yet.

The smell was blamed on the undercoating (?)

Anyway I took the car home and he is going to get in touch with Audi to "see what the actual specs are" (???) and possibly try it with a couple other cars, then get in touch with me.

In the meantime, I have two questions (favors?) to ask for those of you with the car:

1. Would you mind revving it to 7500 in neutral and holding the throttle there at 7500 or so for a few seconds and tell me if you get a crazy-ass shaking? (Try it in 2nd gear, too, if you're feeling kind and adventurous.)

2. Those of you who have hit the rev limiter, where did you hit it and what does it feel like? As I said above, all my previous cars just drop the throttle. They don't shake the damn car.

Thanks a million.

ExhaustNote
10-23-2015, 04:28 PM
7500 is definitely not the rev limit. I been up to 8000+ multiple times and I've hit the rev limiter a few times as well. I do not get crazy shaking at 7500 rpm or when bouncing the rev limiter.

I did misfire once a while back and that caused a really weird shaking and stuttering and a sudden loss of power...but a check engine light accompanied it for a few seconds and then the car went back to normal.
I took it in for service and they didn't find anything wrong and it's been a few thousand miles since then with no issues.

dazed1
10-23-2015, 05:39 PM
7500 is definitely not the rev limit. I been up to 8000+ multiple times and I've hit the rev limiter a few times as well. I do not get crazy shaking at 7500 rpm or when bouncing the rev limiter.


Ditto.

Beast
10-23-2015, 10:46 PM
never experienced this either

LINDW4LL
10-23-2015, 10:51 PM
He said I was "hitting the rev limiter". He kept saying "well, 7500 is pretty high. The engine is really spinning at that level."


Reading shizz like this makes me wonder how some of these service guys ever got their jobs.

Truly incredible. BTW, it sounds like it's misfiring to me- but I can't explain the smell.

acitrano
10-23-2015, 11:28 PM
Reading shizz like this makes me wonder how some of these service guys ever got their jobs.

Truly incredible.

Yes, it's frustrating.



BTW, it sounds like it's misfiring to me- but I can't explain the smell.

Funny you say that, because the way it feels does remind me of how it felt when my S4 was misfiring years ago. Different of course -- the S4 misfired all over the RPM range -- but ... the way the shuddering feels is eerily similar.

ICU2
10-24-2015, 08:46 AM
Reading shizz like this makes me wonder how some of these service guys ever got their jobs.

Truly incredible. BTW, it sounds like it's misfiring to me- but I can't explain the smell.
+1 & although I've only had my 2013 RS5 Cab since July, NEVER had this issue @ 7500 RPM's. 8250 is the rev limit but truth be told I usually drive is "S" mode so the car is shifting on it's own most of the time. I occasionally play w/the paddle shifters when driving but never experienced the shaking you've described. The smell could be undercoating/cosmoline burning off, but odd that the smell coincides w/ the engine noise/shaking. Is that the only time U smell it? Also might help to post in the "regular" side of the A5/S5/RS5 Forum as there will be more exposure to other RS5 owners. Regardless of what the dealership tells you, this is not "Normal".

jkownz
10-24-2015, 08:52 AM
Pop the hood, video record if it can be replicated in neutral. Maybe it could lead to some sort of evidence to give to AoA.

Sent from my SM-N920V using Tapatalk

yas
10-24-2015, 10:05 AM
Call AoA directly. Don't mess around with engine issues - especially $35k high-revving engines. Sounds like this "foreman" just doesn't want your business.

I routinely hit 8100 in my RS (man, I miss that sound).

I will say, I never took it that high before the oil temp was over 200, but if you were on the highway, that's probably not an issue.

matt310
10-26-2015, 04:49 PM
+1 on the video, definitely.

On most cars, you cannot rev to the indicated redline when the vehicle is stationary and wheels aren't moving. I haven't tried in the RS 5 but my previous car was a C63 AMG and would only rev to 6k in neutral.
Also, revving while stopped doesn't produce the same use case since the drivetrain isn't engaged, and there may be something going on with any number of components there.
I'd chalk the burning smell up to new components getting really hot and the cosmoline/underbody spray applied during transit to prevent sea salt from getting onto the bare metal components.

I live in West LA and am happy to meet up with you to compare the two cars. LMK.

-Matt

JamesRS5
10-28-2015, 10:00 AM
Does the RS5 have any run in protection to keep the revs low until the engine considers it self run in?

I'm almost sure mine hit a limiter at 7000rpm when I accidentally over revved it at approximately 800 miles on the clock.

dazed1
10-28-2015, 10:58 AM
Does the RS5 have any run in protection to keep the revs low until the engine considers it self run in?

I'm almost sure mine hit a limiter at 7000rpm when I accidentally over revved it at approximately 800 miles on the clock.

Before the oil is at operating temp, it will auto shift up at around 5-6k, even when in sport + manual. And you shouldnt be going that high when the oil temp is low anyway :o

JamesRS5
10-28-2015, 12:16 PM
I'm aware of the oil temp limitation and wouldn't ever Rev a cold engine, I meant a Rev limiter until a certain amount of miles have ticked over on the clock?

essfour
10-28-2015, 12:54 PM
I'm aware of the oil temp limitation and wouldn't ever Rev a cold engine, I meant a Rev limiter until a certain amount of miles have ticked over on the clock?

no it doesnt have a mileage based limiter.

the engine should power smoothly all the way to redline which is actually 8,250. It sounds fuel related to me, either fuel pump or fuel quality.

it is not the rev limiter, and if you are throwing codes and somehow triggering a limp-mode/fail safe built in, the car would not shudder per se, but rather just cut throttle.

Mojo31
10-28-2015, 02:56 PM
Never had anything like that happen with mine, even using the launch control and shifting at or close to redline.

Smell may be cosmoline burning off.

Pfflyer
03-03-2016, 08:33 AM
Was this issue
ever resolved?

WinterRunner
03-14-2016, 11:18 AM
Did you get a VCDS scan done?