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View Full Version : Hard to take off smoothly, is this just how DBW is?



LaserSVT
September 23rd, 2015, 02:59
I work on cars all day every day and have to test drive them. Since everything has a DBW throttle now I notice things. GM trucks take a moment to think about it when you go to pass but are easy to get off the line. Most Fords it feel like a normal throttle cable. Toyotas are downright snappy with the throttle input and Nissans are hit or miss. My BMW 740i was smooth as silk.
This Audi though, I usually look like an ass trying to drive normal. Now maybe I just need to get used to it, maybe its the tune or maybe something is wrong. Cruising, leisurely passing, fast passing or getting on an on ramp is just fine.
The issue is when at a stop. Light turns green and I push on the throttle a hair like I would my truck or any other car I have ever driven and nothing happens. No I haven't driven the car much at all so it may be impatience but when I tap it and it does not instantly respond I only push a hair harder (maybe 1/8" give or take) and it leaps forward at double to triple the intended acceleration level.

Now I have yet to push it that first little bit and wait for something to happen as the car has been undergoing non-stop maintenance since I got it (so close to done) so maybe I am just not waiting long enough? If it is just a delay I want to fix that in the tune. Its annoying.
On the other hand how common are dead spots in the throttle body and how is the failure rate of TPS A&B (not sure what Audi calls them but everything domestic is A and B.... forget which is pedal and which is throttle body. LOL

Or is that just how these things are? Not sure if my 01.5 S4 was DBW but I don't rememberer any throttle lag in it. Turbo lag yeah but no throttle lag.

GreggPDX
September 23rd, 2015, 05:04
My car does something similar, low speed throttle response feels "notchy" and taking off gently from a stop is difficult to make smooth. I had a similar issue with an A4, and the problem turned out to be accumulated gunk around the throttle plate. The electric throttle motor was not able to smoothly open and close near fully closed. I cleaned the throttle body out with carb cleaner and that fixed the problem on the A4. I intend to do the same on the RS6 soon.

LaserSVT
September 23rd, 2015, 05:22
I was thinking that as we often clean out throttle bodies at work. I guess I will take the bajillion screws out of the air box and pull it to look. Now some cars like Ford say not to use anything other than a damp rag to clean theirs due to the coating they put on them. I wonder if the Audi is as sensitive or if I can just have at it with some MAF cleaner?

DHall1
September 23rd, 2015, 06:08
Sneaky reset

data log

been waiting forever for results. Lol

mine are smooth as butter

Gentleman
September 23rd, 2015, 06:23
Sneaky reset

data log

been waiting forever for results. Lol

mine are smooth as butter


ive been searching, but can you describe sneaky reset? Something with pedal, key and patience?

LaserSVT
September 23rd, 2015, 06:29
Sneaky reset

data log

been waiting forever for results. Lol

mine are smooth as butter

You never said what a sneaky reset is. As for the data I cant do anything until I have the car back! LMAO! :p


EDIT:" Shut off engine, turn it to on (not engine on but electronics on) - step on gas - hold it down - turn key off (don't let go of gas) - u'll hear clicking sounds- then let go of gas pedal."

Is that the correct way?

JSRS6
September 23rd, 2015, 10:55
Pull the negative off the battery terminal and replace after 30 seconds.

lswing
September 23rd, 2015, 16:10
My car has always been smooth all the way through, even with an aggressive tune. Maybe try using Ross-tech to do a Throttle Body adaptation reset.

Or the resets mentioned above could clear things out.

Other thought is old/poor trans fluid or worn TC seals not allowing smooth lockup. You can also log this with Rosstech, and it's interesting to watch the laptop show you the TC activity when driving, really let's you know just what you're feeling.

that said, you do have to be smooth with the right foot.

LaserSVT
September 24th, 2015, 00:34
Pull the negative off the battery terminal and replace after 30 seconds.
I hope that is not the sneaky reset procedure. I have 206 bands of equalization and 8 channels of time alignment to redo if I lose power. LOL


EDIT: 196 bands of EQ.

ttboost
September 24th, 2015, 01:31
Oh you're gonna be pissed when the alternator goes out....and it will...

LaserSVT
September 24th, 2015, 01:59
Are they a common failure? If you are implying due to stereo system draw, the amps only have 800 watts total and I have never seen it put out more than 400 (for millisecond bursts) playing it at an uncomfertable level. It is a pure SQ system, no multi thousand watt amps, no wall of subwoofers or 8 TV screens. Just a lowish power single 10" sub setup. My Fluke amp meter has only seen a peak of 47 amps pulled from the stereo and at normal listening it seems to average 20 amps. Idle is 6 amps. Thats stereo on but music paused. Not sure how accurate that is because the meter seems to be a little wonky when testing below 15 amps.

Now if you are saying the alt will fail at some point because it is an alternator.... well yeah, it happens. I do at least a dozen a month. LOL Never on a V8 Audi but how bad can it be? Cant be worse than a Northstar Caddy or a V6 Escape.
Drop the belly pan (of which I do not have), remove IC hose, move the oil cooler lines, remove serp belt, drop out the bottom. No biggie.


As for the stereo I have come up with an idea. I just need to keep power to the DSP and its wires are easy accss. I am going to splice in a power feed before its power plug to the vehicle and soldier in an XT60 connector. That way I can plug in one of my drones 12v Lipos to it and then unplug the DSP from the car. It retains power and is isolated and I can do what I need to do. Was thinking about it after reading what JSRS6 had said and it seemed the easiest solution.

I need to remove that tiny Walmart battery anyway and put in a proper size AGM unit. :)

DHall1
September 24th, 2015, 04:06
Don't pull battery cable. That is not the sneaky reset

LaserSVT
September 24th, 2015, 05:52
Don't pull battery cable. That is not the sneaky reset
Is the one I outlined the sneaky reset?

Other_Erik
September 24th, 2015, 12:40
You never said what a sneaky reset is. As for the data I cant do anything until I have the car back! LMAO! :p


EDIT:" Shut off engine, turn it to on (not engine on but electronics on) - step on gas - hold it down - turn key off (don't let go of gas) - u'll hear clicking sounds- then let go of gas pedal."

Is that the correct way?

Close enough for government work...

Turn off engine
Key Out
Key In
Turn to Electronics On (Do not crank)
Press gas to floor and hold
Key Off
Key Out
Wait 5-7 seconds (you may or may not hear clicking)
Release gas pedal
Wait 7 minutes before firing up the car
Log Data. 3, 31, 115 turbo mode in 3rd gear from 2500 rpm to redline

okay, enough of that, just being a pain now. You also said something about alternators. 99% chance that at some point in the next 1-3 years you'll need to at least replace the voltage regulator. This is at least 6 hours labor. I would recommend pulling the alternator and having it rebuilt - even if it's just the VREG, you'll have the peace of mind knowing that your brushes and bushings and bearings are all solid when you put it back in. Don't make my mistake and need to pull the alternator twice in 2 weeks.

O_E

DHall1
September 24th, 2015, 15:04
Got to hold gas pedal down 7sec before turning key off

LaserSVT
September 24th, 2015, 17:58
Now you guys have me thinking of pulling it off and having my alt guy do new regulator, bearings and brushes while we do the timing belt just to be safe.

Ya know I searched for a couple years for common issues and maintenance on these cars and thought I had it down pat and knew what I was getting into but 6 hours for an alt.... yikes. The 35k timing service also threw me. That I never bothered checking as I knew the procedure required the nose to come off but figured it was 60-90k like ever other timing belt. Still don't understand why its 35k intervals but it is what it is.

I knew about $100 oil changes and cost of control arms and brake pads (which was thrown out the window since I bought a car with aftermarket brakes) and the fragility of the trans and intercooler leaks etc etc. Funny the extras you lear only after buying the damn thing. LOL

Don't matter, love the car and I aint a broke dick and I have a shop and 100k in tools so repairs are not an issue. :)

P1054
September 24th, 2015, 18:55
Not to split hairs here, but the t-belt interval is actually 40k. 1st one is at 35k, then 75k, 115k, 155k, 195k, etc. And knock on wood, my alternator is still going strong after 2.5 yrs and 40k miles of ownership. Not sure if it's ever been replaced actually, I have the records from the prior owner but don't recall seeing an alternator replacement. So like the transmissions, they don't ALWAYS go out, but often enough it seems to become a known issue.

LaserSVT
September 24th, 2015, 20:34
Not to split hairs here, but the t-belt interval is actually 40k. 1st one is at 35k, then 75k, 115k, 155k, 195k, etc. And knock on wood, my alternator is still going strong after 2.5 yrs and 40k miles of ownership. Not sure if it's ever been replaced actually, I have the records from the prior owner but don't recall seeing an alternator replacement. So like the transmissions, they don't ALWAYS go out, but often enough it seems to become a known issue.

Well now I am really confused. My Audi guy says 35k. Never asked AoA or the Audi dealer and looking it up it seems all over the place. Looked at Blauparts, They do Audi service and say its 75k miles and that some cars have come in just past 100k on the original belt.
http://www.blauparts.com/audi_timing_belt_replacement/42l40v/faq/audi_rs6_timing_belt_change_interval.html

Then there is this other site that says 60k:
http://www.mytimingbelt.com/Results.aspx?ModelId=406

P1054
September 24th, 2015, 20:57
The intervals I listed are straight from the original owner's manual that came with my car. They are also listed on this site in the maintenance sticky thread.

JSRS6
September 24th, 2015, 23:03
Oops. That's a hard reset.
Don't pull battery cable. That is not the sneaky reset

LaserSVT
September 25th, 2015, 00:16
The intervals I listed are straight from the original owner's manual that came with my car. They are also listed on this site in the maintenance sticky thread.

Can I have your manual? Ill give you a dollar. :D

Thats the one item that ieludingng me. Just can not seem to find one for sale. That and the CF trim under the air-bag on the passenger side.

P1054
September 25th, 2015, 03:56
I'm actually rather attached to my manual, but thanks anyway lol. This may help though: http://www.rs6.com/showthread.php/20286-RS6-service-schedule-with-part-numbers

LaserSVT
September 25th, 2015, 04:26
I'm actually rather attached to my manual, but thanks anyway lol. This may help though: http://www.rs6.com/showthread.php/20286-RS6-service-schedule-with-part-numbers
Thanks. I have read that one. What I have learned in my short time here is that pretty much everyone here knows these cars inside and out. I have not been steered wrong. Every bit of advice and input has so far been invaluable and really I have learned more here in the last few weeks than I had doing random research for 3 years trying to learn all I could about this site.
An aquatence on a C5 Face Book group said I needed to check this place out and was the place to be for anything RS6 related. Previously I was stuck with whatever missinformation Google decided to spew that day. Also was on Audi World for a long time studying when I thought I was going to have to settle for an A6 2.7T but there is no help or knowledge there for the RS6 and there seem to be quite a few.... questionable people there.
So yeah, I was not doubting you at all. One I was trying to be light hearted kinda funny and just though it interesting in what so many places claim as far as service interval.

As for the manual, I just want one. I like my cars complete. I am pretty sure I know how to opperate everything on the car as its from the era when I was a manager for a super tiny Audy dealer and took home new A6s all the time before I bought my S4. But like I said, I just want all the stuff. Like when the tow truck came for the car and I discovered the tow eyelet was missing from the jack tray and that the foam on the end broke. My fault as I grabbed it not realizing it was only a piece of foam. So yeah, now trying to find that foam tray and a tow hook. LOL