Juddering gear change - B5 1999 A4 Avant 1.8 SE (Auto)
Im completely new to this forum so please feel free to let me know if I havent adhered to forum etiquette!
I have a 1999 audi a4 avant 1.8 SE(auto). Just recently the gearbox has been behaving strangley when shifting both up and down through the gears. Instead of the smooth change, there is a very noticeable judder before it shifts up. On the down shift it still happens but is less pronounced. I can only only describe it as feeling similar to when a car is running out of fuel, or when there is dirt in the fuel line and the car jolts slightly, however this car only has 70,000 miles on the clock and has had lots of fuel in the tank when this has happened. This has only happened twice since Ive owned it (approx 3 weeks), once 2 weeks ago, and just this evening. There doesnt seem to be any rythym or rule as to when it occurs, so cant offer any info as to connecting symptoms! Can anyone help?! Im concerned that this could be a serious and expensive problem like a faulty gearbox or ECU, but hoping it might be something less serious.
If you own a scan tool or know someone who owns one.. use it to inspect the running diameters on a test drive & at idle, compare measurements to OEM specs.. check for any DTC's.. if there are any present fault codes concerning the automatic transmission, it could help in diagnosing with the juddering shift problem...
Does it judder in a certain gear or all gears affected? Depending on what gears it affects will help determine if it is a mechanical failure, electrical or both. From what your describing sounds like a shift solenoid problem, possible damage to clutch discs & gears inside the tranny, possible ECU malfunction, low tranny oil, or possible contamination inside tranny.. Diagnosing will take a lot of testing..