I have searched the forum for the same problem my 04 2.7t is doing.... no direction tosolve the problem........????

I have an automatic s line and some times(not all the time,more often whem stopped and turning a corner)when I start from a stop and start up with normal gas pedal accelleration the care feels like the turbo has turned off 1st through 3rd gear (it also rpms high through each gear)
I have to push the pedal down more than normal to get it going, then it really takes off. I know this is not normal. I have vagcom and have checked for codes and did the TBA adjustments.I changed the spark plugs,put a new K&N filter and had the TBelt service done.(currently 76000 miles)

Could it be a bad sensor,leaky vacum hose,someting to do with thetransmission,do I need a new fuel filter (I use the high octane fuel), could it be a clogged cat, or dirty throttle body??????

I know if I take it to the shop,they will hook it up to vagcom and find nothing like I did. Is there somewhere in vagcom I am overlooking to see if I can identify the problem source?

This has been very frustrating [:@]to me as I just bought this car and has seemed like all it likes is money!!! I hope it is nothing major or is thisjust how these care run!!!

If you can tell me where to start to eliminate the problem.... Please help if you can. :) Thanks!!!

Well since you have a vag com lets look at some data blocks.
Find your throttle angle percentage, this shouldn't be over 2.5% when the engine is running. I think its somewhere between 1 and 5 in the engine electronics.
Check the coolant temp when the engine is running, rev the engine and check to see if the coolant temp does anything crazy like go to -40 degrees for a split second or something like that.
Look at the Mass airflow sensor data, it should register in g/s. It shouldn't be higher than 6.0 at idle, also make sure it stays steady.
Then go to data block 32 which is the fuel trim, make sure its close to 0%, if its higher than 1% + or - post what it is.
Lastly find the O2 sensors and see what those are, to make sure there isn't a vaccum leak.

Thanks for you expertise and asking questions to help,I realy appriciate it very much. I highlighted in redanswers below to make this as simple as possible.There are so many different codes to look for anddo you thinkit wouldbe a good idea to get a shop manual to know what to look for? There is definitely something going wrong in this car,and I hope it is simple and nothing major such as transmission,tork converter or turbo issue...that would be a big bummer!![:@]

Well since you have a vag com lets look at some data blocks.
Find your throttle angle percentage, this shouldn't be over 2.5% when the engine is running. I think its somewhere between 1 and 5 in the engine electronics.
003-@650rpm throttle angle shows 2.4 to 2.7% it jumps aroundvery fast. mass air in this block is 358g/s

Check the coolant temp when the engine is running, rev the engine and check to see if the coolant temp does anything crazy like go to -40 degrees for a split second or something like that.
001 -engine temp is constant warmed up to 96 and stayed throttle or not

Look at the Mass airflow sensor data, it should register in g/s. It shouldn't be higher than 6.0 at idle, also make sure it stays steady.
002 - load measurement @650 rpm mass air 3.47 -4.00g/s Jumps inbetween numbers very fast

Then go to data block 32 which is the fuel trim, make sure its close to 0%, if its higher than 1% + or - post what it is.
032 - ??I tried tofind fuel trimin 032 but must be another number? I looked in engine measure blocks,is it somewhere else?

Lastly find the O2 sensors and see what those are, to make sure there isn't a vaccum leak.
002 - 02 bank 1 @680rpm idle 0.8 to 3.9 @1500rpm0 to -3.3 the numbers change very fast back an forth
02 bank 2@650rpm idle -3.9 to 1.6 @1500rpm 0 to -3.1the numbers change very fast back and forth

Again,thanks for your imput and helping with my frustration.:D

Everything looks ok except for the mass air flow at 358g/s in the data block 003, are you sure it didn't read 3.5g/s?
I would try taking out the mass air flow sensor and cleaning it with some electrical contact cleaner that you can get at any auto parts store.

Check your air filter too, if its really dirty change it.
As for the repair manual, no manual will tell you what the data blocks are. Hell, on the factory tool it doesn't even tell us what were looking at! The VAG COM is better than the factory tool, at least it tells you what your looking at!

sorry It did show 3.58 in 003

It also showed 3.47 -4.00 in 002 jumping around quite quickly.

where else could I look for the fuel trim? I tried 032

I put a new K&n filter in the car when I changed the plugs I will clean the air mass sensor to see if that helps.

What about a new fuel filter and a good cleaner to run in the gas to help clean the injectors??

Thanks

This car sucks the gas...Irange from 13-15 in town even when I drive like granny

Ahhh, the K&N filter may the problem. K&N filters use oil which is known to foul up the mass air flow sensors. I use a K&N filter too, but i washed it so the oil isn't present. Try cleaning the mass air flow sensor, it should fix the problem if no fault codes are present.

As for data block 32, it should be fuel trim. You might wanna re-check it, but as far as the O2 sensors are reading, it really doesn't matter.

I never thought about that.....I will go buy a cheap air filter to use while I clean the K&n and then clean the sensor

What are your thoughts for a new fuel filter and a good injector cleaner???

Thanks for your advise!!

Fuel filters are a good PM maintance at around 80k, but they usually don't cause problems.
Fuel injector cleaners really aren't needed if you use good fuels, but if you want to do it anyway, the dealer has the best fuel system cleaners such as BG. If you just wanna get them cleaned up a little bit pour a can of seafoam into the gas tank which you can get at any auto parts store.

Thanks!!
I forgot about the seafoam.I have used it before and had good results in a different rig.
The car is at about 77000 and I might as well change the fuel filter.I need to chane my gas fill uptocheveron instead of Flying J. I always use the highest octane and should know better to get it at a cheveron as I used to own a Subaru turbo 2.2.

Thanks for all your help!!!

Great info by Auditech79 as usual...

As for Seafoam and Fuel filter, I would do the seafoam first, then change the filter after you go through a tank of gas. Fuel filter is located on the right side of the car right in front of the rear wheel well. You need 17 mm, 19 mm and an adjustable crescent wrench to replace the filter. Also be sure to get 4 aluminum sealing washers to replace the existing. Becareful, because 2 inlet washers are larger than the 2 outlet washers. I had an issue with ordering 4 washers from internet thinking that they would get it right, but all 4 were the same. I had to go to a local hardware store to get different ones.

As for replacing the filter, pull your fuel pump fuse. Start the car and let it just die. Open the fuel door to release pressure in the gas tank, then loosen the fuel hoses. You will see a lot of fuel spilling out of the line, but it is ok. Also don't forget M10 triple square bit for the strap that holds the fuel filter.

Once the fuel filter is installed, reinstall the fuse for the fuel pump. Check and make sure your gas cap is closed, and restart the car. It will take a few cranks to start. Once started turn it off and recheck the fuel hose connections to the filter. Make sure it is not leaking.

After seafoam, fuel filter and routine maintenance stuff, my car runs a lot better now. It is definitely noticible.

hxgaser,

Thank you for the information,its nice to have comments and informationfrom someone that has had experience going through the motions...and yes ditto!!....Auditech79 has been very helpfull and instructfull with great information......Thanks Auditech79!!!!

I will run a tank of gaswith seafoam first (should not take long as this car is not the greatest on gas 13-15mpg in town) And then make sure I have all the correct washers and tools to follow the procedure to install new fuel filter. Its fun to drive even with the low mpg.

Meanwhile I need to get cleaner and clean air mass sensor and clean air filter to remove oil if present. I will do all this and post results...fingers crossed it will help throttle problem.:D

For now, Thanks to all!!!

Gcan,

I'm not that technical when it comes to cars so I can't offer any advice here but I can tell you that your gas mileage seems extremely bad. I too have an '04 A6 2.7T S-Line so our cars should be identical mechanically. I live in the city of Pittsburgh with a 16 mile commute each way everyday of solid city driving and average 18-19 mpg.

Danstr1

Yes, whenI drive causal, it is at best 15mpg in townand drops to 13mpg with heavy foot.
My 02 4x4 dodge turbo diesel truck gets better gas mileage,though it is not as fun to drive

I always park in a garage and it is an automatic.Tune up made no difference and maybe it is the combo of dirty air mass sensor or something else? The only thing I can do is make sure tires have correct air pressure,put in a good gas -cheveron or Shell and hope for the best after I take care of the air mass and filter!!

I will post results after looking into these issues.Thanks for your imput on gas milage,I love everything else about this car so far.

Just an observation - I had the gas filter changed on my 03 for the first time, at 107k. No problems, just a precaution. I vaguely remember the shop saying they pinched off the fuel line so it wouldn't drain out as described above - this would only work if the fuel line is rubber. On other cars, I have inserted a golf tee into the line to stop the gas from leaking out while I change the filter.

Finally, I use a K&N and after reading posts about the MAF, I let it sit out on newspaper overnight to drain off the excess oil.

Yeah your gas mileage should be closer to 18 MPG's on average. Its just another the engine is telling you its not running correctly. Possible causes are a plugged air filter, mass air flow sensor malfunction, or a vaccum leak. I doubt the fuel pressure regulator is bad.

ORIGINAL: ppgoal

... I vaguely remember the shop saying they pinched off the fuel line so it wouldn't drain out as described above - this would only work if the fuel line is rubber. On other cars, I have inserted a golf tee into the line to stop the gas from leaking out while I change the filter...



Geez you could have told me about crimping the lines earlier.:D Anyways, yup that would have saved me about 1 qt of gas. As for the golf tee, our cars have banjo fittings, so it wouldn't have worked. Good advise though.

gcan, let us know what happens. It is always good for us to find out about the symtom and end result.

Auditech79,

I did as you instructed, pulled air mass (cylinder pipe)and spray cleaned on a shop towelwith air mass cleaner from auto parts store,cleaned air box and installed new air cleaner.

No difference in how it reacts......other possibilities??? What direction /angle should I take now??

The way the engine runsis not consistant,you would think with a vacum leak it would effect it all the time Maybe I should check the hoses..do you know where I could get a diagram to find all the correct hoses? I know when I let off the gas it feels as if it downshifts,like it is a vacum leak?? seems worse after stop the turning right or left.

Also could it be a function with the transmission learning feature?? I read somewhere that it can be reset so it can learn to shift wth the drivers habit. I hear the battery need to be unhooked for awhile todo this. I have been there before, un hooking the battery put a bunch of codes and car drove lously,I had to have a shop techclear them(I did not have vagcom at that time)

I adjusted the tba and am running out of options

Any directions/ thoughts would be greatly appriciated

Thanks.......

Every time you erase the fault codes you erase the transmission leaning adaption.

I would double check for codes in the gearbox electronics and brake electronics.
If there aren't any codes then i would start to look for a vaccum leak. Its probably a small leak so a smoke tester would be needed to find the leak in the intake. Have the dealer or a euro shop complete this for you.

Other than that i have no idea, i would actually have to drive the car to know its behavior.

auditech79

Thanks for your response,I have one more question and I will probably give this up

About a week ago my brake lights stayed on constantly. I replaced the brake swith and cleared the codes..does the brake switch (above the pedal) have anything to do with the driveability? I had trouble getting the new switch to work after clearing codes several times,there are currently no brake/tranny/esp codes. Could the switch be faulty??

Another thing I notice when I start the car I hear two clicks under the dash around the fuse box/light switchand when it clicks the idle drops for a secondto almost stall and then recovers. No other equiptment is on and my foot is off the brake. May not be anything but I never noticed this before.

Thanks again.Wish it was more simple,but how could it be with all the fancy electronics they load on these rigs....its no wonder they don't last a long time and need lots on maintenence.

ORIGINAL: gcan

auditech79

Thanks for your response,I have one more question and I will probably give this up

About a week ago my brake lights stayed on constantly. I replaced the brake swith and cleared the codes..does the brake switch (above the pedal) have anything to do with the driveability? I had trouble getting the new switch to work after clearing codes several times,there are currently no brake/tranny/esp codes. Could the switch be faulty??

Another thing I notice when I start the car I hear two clicks under the dash around the fuse box/light switchand when it clicks the idle drops for a secondto almost stall and then recovers. No other equiptment is on and my foot is off the brake. May not be anything but I never noticed this before.

Thanks again.Wish it was more simple,but how could it be with all the fancy electronics they load on these rigs....its no wonder they don't last a long time and need lots on maintenence.



Sorry for the late response, but yes the brake light switch can cause all kinds of problems.
The reason you had a hard time clearing the code after you installed it is because you broke the switch. I break them all the time, the manufacture that makes them had their head up their ass when they designed it or something. There is a way of checking the switch with the VAG COM using data block 2 i believe in the brake electronics. Very slowly depress the brake pedal and you should see two settings in the block switch to activated. Now these have to happen one after the other, if they both activate at the same time the switch is bad, or if the bottom one activates before the top one the switch is bad. Replace the switch again if its out of spec.
To install the new switch without breaking it push the switch in firmly and turn it until it snaps into place, if it doesn't want to turn DON'T FORCE IT! Pull it out and try it again. When your done, if the lights stay on or don't come on at allremove the switch and pull out the lever all the way and re-install it until it works. Then double check the operation of the switch with the VAG.

auditec79,

Thanks for your respones .I checked brake light switch in vagcom as you instructed and the light in the secondrow came on first before the other light as you instructed.I musthave installed it correctly.

Tell me something....I am thinking of selling my Audi based on the negative from all the dealers.I am finding out that dealers would not prefer to take them as trades. Whats up with that??? Do they all have ahigh risk break down/repair failure?? You probably see all the problems with them...are they all that bad and expensive when they get close to 100,00 miles?

Thanks for your advice



local://upfiles/47017/E29752D88B154234A37829947C4DC34F.jpg

Hmm, slow throttle response and bad fuel economy... Maybe your Torque Converter is going out. Check for tansmission codes using vag-com

R Evolution1

That is a possibility,but no codes in vagcom for transmission, and not sure how to check without spending the big bucks.
I want to experience the possibility to change the code,but so far no one in the forum has replied to my tranmission code post ,lots of lookers.

Thanks for your reply


local://upfiles/47017/9FA6CA339D1F46D888C0A6F19A03192C.jpg

ORIGINAL: gcan

auditec79,

Thanks for your respones .I checked brake light switch in vagcom as you instructed and the light in the secondrow came on first before the other light as you instructed.I musthave installed it correctly.

Tell me something....I am thinking of selling my Audi based on the negative from all the dealers.I am finding out that dealers would not prefer to take them as trades. Whats up with that??? Do they all have ahigh risk break down/repair failure?? You probably see all the problems with them...are they all that bad and expensive when they get close to 100,00 miles?

Thanks for your advice



local://upfiles/47017/E29752D88B154234A37829947C4DC34F.jpg


No your switch is broken if the second detent activated before the first one, you have a broken switch, replace it.
As for people not wanting to take them in for trades is because the mechanics don't know how to work on them. When i used to work at PEP Boys back in the day people used to crap their pants when the four rings of hell rolled up! Audi's are some of the hardest cars to work on besides SAAB.

Good info Auditech.

However, I won't be surprised if the entire problem is because of K&N. During my two weeks with that filter, it played nasty with my gas consumption, performance etc. Though, I never washed the oil off it, like you did. So, I changed it back to the regular one, and it solved everything.