Looking for advice on noticeable acceleration loss, slightly "jerky" automatic shifting & increasing idle roughness over the past 3 years. I am very gentle on the car and generally accelerate slowly. The old beast just doesn't have the moderate quickness she had when previously called upon.


My Ideas:
-Change fuel filter and/or pump.
-Spring for new/better performing plugs.
-Transmission fluid flush (apparently controversial).
-Upgrade intake (a little to Fast and Furious for me).

Misc Info:

-Timing belt, water pump & new plugs at 95K provided no improvement.
-Fuel system flush provides brief improvement.
-ECU fuse expired resulting in numerous error codes. Car was driven for approximately 10 miles while misfiring (potential cat damage?).
-Engine oil and thermostat running warmer over the past few years.

Any help would be much appreciated.

-E

 

Without knowing how many miles (but more than 95K) are on your car I would also consider the following:

checking out the coils
clean out the injector nozzles
clean out the throttle body (sometimes the butterfly will stick closed which could account for jerkiness)
checking out the catalytic converter(s) since you indicated possible damage

Good luck as my car has roughly the same mileage.

Hmm, you have 1 post and I have 9. This could be a case of the blind leading the blind. Maybe one of our more experienced members can lead us out of the wilderness.

Mike

 

I know when my A6 3.0 had a air leak right where the intake pipe meets the manifold it gave problems VERY similar to yours. So verify you have no leaks which would make it pull in air after the MAF sensor... Also check for vacuum leaks.

 

"This could be a case of the blind leading the blind"

You've made my day. Good catch!!!
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Past 3-years are in mileage-wise ..... (how much)?

The relativity of the notion "gradual loss of acceleration" is of no argument here.
Only very few thing in life get better with the age... cars are not on the list.

What kind of fuel system flush you mentioned-describe it!

Open the spark plugs- look for the color of the electrodes!

Replacing the fuel and air filters is a no brainer -do it!

BTW-the warmer running engine-the higher is the efficiency.

If you have access to VAG com you could monitor and log numerous data performance and functionally relevant in a driving mode.

Have you ever tested your emissions with gas-analyzer?
This the way to figure out the engine state and the cats state.

 

After check out air, vacuum leak, I would start with tranny fluid filter change. The garage doing this should be specialized in Audi, not JiffyL

I had the tranny service. I feel the performance is night and day. Like you've drag the dog (before) and now the dog is pulling you (after). Plus I have differential (there are 3 diffy, front center, rear, in quattro) fluid drain and fill the car is much quiet now.

 

Just for curiousity sake, how much is the tranny fluid? My Jaguar has a ZF transmission and the fluid up until recently was about $65 per quart. In order to change the fluid you needed to heat up the fluid to about 100 F, use a specialized refill piece of equipment and hire a druid priest.

 

It took over 2 hrs labor and $150 for liquid + filter. My bill is $360.-

The guide to perform fluid & filter change ... not as simple as JiffLube & require proper fluid ... probably need to hook up VAG-COM to monitor fluid temp.

http://www.zf.com/na/content/media/u...rs/5HP19FL.pdf
http://www.zf.com/na/content/media/u...s/5HP19FLA.pdf

 

The spark plugs were recently changed.

I've got a VAG COM but have only used it to check/clear codes. Reading of data logs is a little beyond me at this juncture. If you could point me to some literature on the subject or provide guidance if I generate logs I would appreciate it. Would really love to confirm the status of the CATS.

Thank you for the information.

 

Got a VAG Com, some lifts and will likely perform the transmission service myself. Going to follow the instructions in my Haynes manual which has proved to be effective for other services.

Thank you for the info.

 

The injector nozzles are okay, the throttle body is fine and not sure yet on the cats.