1.9TDi Avant engine judder at rest

[wozo66]

Hi

Newbie to the site. I have a 98 TDi Avant that runs beautifully but has suddenly developed a very slight judder when it's parked in neutral or, for example, when I'm stopped at traffic lights. A very slight push on the accelerator clears it for a couple of seconds but then it reverts back to this annoying vibration. It feels as though there may be a slight blockage somewhere that a good 'pedal to metal' would clear, but it hasn't. Could this be an indication of a blocked fuel/air filter or is somethng more sinister coming to the fore? I'm one of these owners who would rather have a go myself at solving the problem before taking it to a garage and the mechanic making me out to be a right berk!! Any suggestions would be really welcome. Thanks in advance. wozo66:confused:

[jims audi]

I have got exactly the same problem with my 98 1.9tdi! exactly how you described. very annoying because it doesnt affect the way the car drives but there is obviously somthing not right. have done nothing about it.
HELP US! LOL.:confused:

[wozo66]

Hi Jims Audi

Looks like me and you against the rest! I think I may have found a possible solution! I noticed after the judder began, my temperature gauge began to falter. When I consulted the Haynes manual, it goes on about two sensors, one for the temperature gauge and one for the engine management system. I checked a local parts company for a replacement of the temp. sensor and he said for my car there is only one sensor for both the temp and the engine management system - when I looked, he was correct. So I replaced it. The temp gauge works fine but the judder is still there. On further checking the Haynes manual, it says that should the engine management sensor fail the car will run on a 'plan B' mode which isn't as efficient and will make the car run 'not at its best'. So, I am assuming that although the sensor has been replaced the car is running on the 'plan B' mode and maybe needs a VAG COM check to clear it, which should mean the car runs on information via the new sensor. What do you think and more to the point, can anyone confirm that this theory may be correct?

Thanks

wozo66