Sometimes when i start my car it idles at around 1250 and then after like 10 min it bounces down. Never holds at a RPM steady, teh needle will bounce. Why is this?

 

because your car is ready to "Explode"... better hurry up and get that S4!

 

Thats not funny red, he will prolly evacuate his neighborhood now and call the bomb squad.

 

Ohh sorry.. umm its okay.. it wont blow i swear!!



(Grinning and waiting for the news report tonight)

 

haha no, but really i know its not gonna explode but is it a sign of something else in teh engine going bad or does it not matter and is just b/c the engine is cold?


PS bomb squad said it was alright and that i can go back to my house.

 

redgoat is on a roll today .... lol

anyway ... yeah i dont know if this applies to a4's or not but i know some cars idle higher in colder temps. think it has somthing to deal with making sure the engine doesnt cut off since it is soo cold. not sure though. i live in wisconsin and in the past 2 weeks its been colder and my a4 will idle at about 1100 for a lil while until its warmed up then settle back down to around 500. and this is the first winter i've had it so i guess just wait and see. i'm ready for some snow though !

 

i don't know if your battery died recently, but when mine did, the computer somehow "forgot" the proper idling speed.

took it over to the dealer and they hooked it up to one of those computers and ran a test. the test showed two numbers...the proper idling info for my car and the wrong info my car currently was thinking was correct. he punched some keys and...my computer was reprogrammed. in two seconds it was all better.

crazy.

not sure if that's your problem, but if your battery just died, it could be.

 

i kno i have a new battery but i didnt put it in making it more than a year old. did the dealer charge u for that?

 

If you have replaced or disconnected the battery you can get this problem;

Idle speed which is either fluctuating or excessive
Cause:
The idle speed components are lacking electronic adjustment after a voltage loss in the system (for example
after the disconnection of the battery, control unit change and a problem with the voltage).
Models affected:
ABK, ABC engine
Service:
Referring to the workshop manual do a basic setting with V.A.G 1551 . Throttle valve potentiometers and idle
stabilisation valves have been unnecessarily changed too often because of lacking system adjustment. If the
complaint is not corrected with the basic setting, then a component is defective. It must be located by
referring to the workshop manual.

Or:

Wavering idle speed with cold/warm engine.
Cause:
A smaller vacuum hose branches off from the crankcase ventilation, which is routed as bypass around the throttle
valve. Especially in winter the throttle hose and/or the vacuum hose can become clogged and/or iced up with crankcase
condense water. Consequently the idle speed wavers by several 100 rpm during the phase of warming up, gradually
dying down as the engine heats up.
Pulsations in the air inlet hose are possible through the crankcase ventilation.
This leads mainly to wavering idle speed with switched on electrical consumers and air conditioning with a warm engine.
Models affected:
ADP engine 1.6 l
Service:
Take away the intake hose complete with crankcase ventilation hose and vacuum hose.
Clean the throttle hole, 2 mm (4) diameter, and hose of the vacuum (3). Take away the cylinder head cover, put in
the new oil splash guard and get rid of the old one - Part No. 06A 103 544 - (unscrewed).
Adjust the cylinder head cover and intake hose. Do not lose the O ring and make sure it doesn't lose itself in the neck
of the crankcase ventilation hose. A tiny wavering of idle speed by approx. 50 rpm when the vehicle is still rolling
and the clutch is pressed down is no cause for concern and is normal.

 

well, my car is an '02 and still under original warranty, so i don't even pay for labor.

if what my problem was is in fact the same problem you are encountering, it is a surprisingly easy fix and i am sure you could just tell a technician you want him to hook you up to the computer and see if all you need is to recalibrate your computer's info for idling. if you wait there and they can fit you in, i wouldn't be surprised if they don't charge you.

it should be noted that most of my dealer experience is based on the dealer near me, which is highly regarded for its service. i always expect, and receive great service from them (Biener Audi in Great Neck.) Although, i must say i have had nothing but top-notch service no matter where i take my car. The dealer near my college has been great too, although not quite as polished as Biener. I would expect the service we get for our cars at any dealership to be top notch.

Anyway, yeah if you just changed the battery, just removing it and replacing it with a new one could cause the same problem i had. Get that checked out. it could be an easy fix.

either way, you'll find out what the problem is...either they'll be able to fix it in two seconds or they'll tell you what you gotta fix.

good luck with that.