Re: Knock Sensor

[Jim Griffin <JGriff@pobox.com>]

Mike,

I noticed a slight part-throttle hesitation last year, and the dealership
(correctly) diagnosed it as a bad spark plug wire. Since they are $40.00
apiece, they replaced just the one bad wire. I noticed this year that I
began having the same problem. I figured that I would try a whole new set,
since they hadn't been replaced yet, and the car now has 100k miles on it.
Sure enough, that cured it. It now runs beautifully again. Have you tried
replacing the plug wires, etc...?

I'm glad that I went with the "cheaper" fix first... I almost went to the
trouble and expense of replacing the O2 sensors (at a whopping $360.00 for
parts alone!!) at my *own* thought that they might be bad, given the mileage
and some other reasons. Considering the high price, I decided not to trust
my own (unscientific, un-technical) diagnosis. I spoke to a trustworthy
mechanic, and he agreed that I was correct in trying the plug wires first.
It was a worthwhile phone call.

So, although you spent the $$ to have them diagnosis it, don't feel bad.
Sometimes it is better to have someone qualified to look at it, to try and
solve the problem in the quickest and cheapest manner. I've certainly been
my own worst enemy several times by spending $$$ on unnecessary replacement
parts based on what I *thought* it was.

Sorry to hear that they weren't able to fix the problem. As long as you
trust this place, try not to begrudge them. Keep in mind that cars
(especially Audis) are very complex nowadays (i.e. not quite as easy as a
1960's slant-six Dodge), and equally complex to figure out when something
goes wrong. Hopefully, your answer lies somewhere here within this group...
it has for me and others several times!!


Good luck.


At 09:25 AM 01/30/97 -0800, you wrote:
>After trying to figure why my car was hesitating for the past few months 
>I broke down and took it to the dealer for diagnosis. Five hours later I 
>was told that they had narrowed it down to the knock sensor. They had 
>checked my entire fuel system and that was fine, but the knock sensor 
>was giving the computer bad codes. Along with the hesitation I was 
>getting poor gas milage and the emissions check light was coming. Since 
>the diagnosis was done the emissions light no longer comes on, but the 
>hesitation is still there. Since they had not even completed the tests 
>or done any repairs I sheduled they appointment to finish up the 
>diagnosis and see if I wanted them to repair it. Then when I tried to 
>leave with my car I was slapped with a bill for $150 for three hours of 
>labor just for them trying to figure out what was wrong with it. Also, 
>on the way home I notice one of my seats had been gouged by a careless 
>mechanic. I want to know if the information they gave me sounds correct 
>after going through all this nonsense. I hope someone can help me.
>
>
>Mike DePolo
>'89 200tq


                             Jim Griffin
                      JGriff@pobox.com
  http://www.geocities.com/MotorCity/4475
                        Maryland, USA
   "Perception is often stronger than reality!"
                               '92 100S
~~~~~~~~~~~~~~OOOO~~~~~~~~~~~~~~