KeithSam

Hey guys,

The Audi is driving very poorly, LACKS POWER & ACCELERATION. KICKDOWN Even in Sport mode is nonexistent!

A little history of last few months:

The Oil Pressure light comes on sporadically during warm weather highway driving, ever since I owned it but I ignored it since Audi’s are notorious for false codes and defective sensors.
Replaced sensor and checked oil pressure. Still happens on hot days!


I also stupidly pulled a Kramer and allowed the car to run out of gas about 2-3 weeks back. Sediment in fuel lines, fuel filter or fuel pumps? I do tend to overdo the engine additives (to increase compression-to solve oil pressure warning…..) and gas additives at gas fill ups…… bad O2 sensors or cats??

Lastly, I had to replace my mass air flow sensor about 5 weeks ago. A generic cheapie or installed wrong, is that possible? The idle is fine, although a tad jumpy.

The car drives fine otherwise but it just does not seem to have the same zip it had just months ago, it seems to lack power and proper kick down.

My wife as a 1995 Jag XJR and it has wayyyyyyy more torque, pickup and acceleration even power, than my newer 2004 A4.

My thoughts are either bad O2 sensors (check engine light indicate bad sensor ONCE a few days ago but not since) or fouled or clogged cats.

Ideas? Desperate!


Thanks,

Keith.
Mt View, CA


PS-I know, I've done some stupid things!

lyleswk

Some thoughts.

I assume you have the 3.0. Assuming that, comparing that car with an XJR is not a fair comparison. The XJR has a supercharged 4.0 liter engine; I think it is pushing 400 ft lbs versus just north of 200. Both the displacement and supercharger give more torque versus horsepower. And, the cars are not significantly different in weight. So, the Jag will always easily pull 6 sec to 60 versus 8ish second pulls to 60 for the Audi.

Next, don't ignore the oil pressure light and assume you are referring to the RED warning versus the YELLOW oil level light. Having an oil pressure light on a 3.0 is very rare, so address the situation. Having said that, not sure where you got the impression that Audi sensors are any worse than any other car. Also, doubt this is related to your issue unless you have driven long enough to wear piston rings / cams / valves due to low oil pressure.

I would change your filter because it is easy and may solve your problem. I would also buy a real MAF and put that in the car. While you are at it, get a VAGCOM code download and see what intermittent (if any) codes you have. And finally, I would not overdo the additives. You would get a CEL if your cats / O2 sensors are suspect, so don't jump there.

There is a firehose input...

KeithSam

Lyleswk,

THANKS for your reply!
I have been trying NOT to ignore the oil pressure light, I’ve changed the oil, filter, oil sensors, etc. Only think left is to check the condition of the PCV valve and the crankcase breather hoses, to make sure not plugged with whitish gunk, and perhaps use a higher weight oil- 10W60?

Keith

lyleswk

I wouldn't go against the manufacturer recommendations which does not go that viscous for any engine; see link below for all the different specs Audi recommends and reference your manual for the 3.0 to determine which spec.

As far as your light, doubt PCV is the issue. It is more likely a sensor, clogged screen, or pump. Sensor should have a code and is by far the easiest. If either a clogged screen or pump, you will need to attach a pressure gage to the system to see if it meets specs.

http://microsites.audiusa.com/ngw/09..._1997-2012.pdf

KeithSam

Thank you lyleswk