Hi just got an audi a4 2001, 1.9tdi 130bhp, the windows keep fogging up and there doesnt seem to be air coming out of the vent for the front windscreen??? can anyone help??? the back windown is fogging up too..thanks

SOURCE: 2003 Audi A4 FSI Sport No Air coming out of Windscreen Air Vents

UNDO THE SCREWS FOR THE GLOVEBOX LIFT OUT THE WAY AND ON YOUR RIGHT HANDSIDE YOU WILL SEE 3 AIR DISTRIBUTION FLAP MOTORS ,THE ONE FOR THE WINDSCREEN IS THE NEAREST TO THE BULKHEAD. YOU CAN TEST THE BLOWERS AND YOU WILL SEE THE MOTOR VENTS WORKING OR THE ONE NOT WORKING IN YOUR CASE ..

SOURCE: Audi A4 2004. Vent is centre of windscreen seems

flap motor that controls the screen vent needs replacing

SOURCE: my windscreen wipers have stopped working i have

First you must diagnose why windscreen wipers going slow and/or stopping.
In order to find out the cause of wipers stopping you can try follows: 1. Carefully extract the wiper arms from their axles (two pieces). In some cases you need to use an extracting tool. Heed of the windscreen !!! 2. Disassemble the plastic covers from the bottom of the windscreen. 3. With the bonnet up you can start the engine, (transmission in "N" or "P" position and parking brake on). Now you must switch on the control lever of the wipers, and go to the engine compartment. If the wiper motor runs let the wiper motor running for a few minutes and switch off. Go to the step 4. If the wiper motor do not runs you must check first the electrical feeding of the motor. It is necessary to unscrew three bolts of the mechanism and disconnect the electrical coupling (difficult assurance). If the electrical feeding is OK you must replace the motor - steps 5, 6, 7. If not you must check electrical connections, the control switch of wipers and electric cables. 4. Now you must check the two bearings of wiper mechanism with your hand. In the most cases the left bearing is out of order (is very hot). This is the most encounter fault of the wipers running at Audi. 5. For have enough space to manipulation the wiper motor together with their mechanism you must extract the plastic cover of the engine computer box, and extract also the box screws. Then you can move slowly the engine computer box, just for a few milimeters. 6. You must disconnect the electrical coupling of the motor (difficult assurance), unscrew three bolts of the mechanism and extract together with the motor. You must move them slowly between windscreen and engine computer box until the wiper motor go out together with the mechanism. This is the most difficult operation! 7. Now you can repair the bearings, replace entire wiper mechanism or replace the wiper motor. It is not very simply, but it works.
Heed of the windscreen !!!
Refit all in reverse order.

SOURCE: I have an Audi A4

Sounds like you have a leaking heater core.

SOURCE: Audi A4 1.9 TDI 130BHP engine power loss when it's raining

This is the correct solution..........replace the solenoid valve N239 as the electrical connection is affected by dampness. What happens is that the EGR valve is jammed open by the solenoid and this allows oxygen starved air into the cylinders (exhaust gas) and combustion is poor.
Quick fix is to disconnect the vac hose to the EGR actuator and block the end with a self tapping screw or pencil. This will work for sure....