I have an 07 Audi Q7 3.6 without the mechanical vacuum pump. Is it possible to replace this motor with the version with the mechanical vacuum pump???

Dear John,
I am glad you only replaced that switch!
The best action to take for that symptom is to have a mechanic unscrew that O P switch and insert a oil pressure gauge and test the oil pressure with a meter, hot and cold.
If it is not up to par when hot, there are several possibilities.
1) If the oil is fresh & the right viscosity, you could have a failing or a leaking oil pump. It can leak inside the engine.
2) You may have a plugged up oil screen on the oil pump.
3) You may have a bearing or some other such part failing causing an engine oil hemorrhage inside the motor.
An authorized and helpful Audi dealership should be able to tell you if other Audis are having this problem and what is causing it.
God bless your efforts.

you have left a wiring loom connection off from the sound of it ,no idea where but have a good look tomorrow,best of british with it

CHECK CRUISE CONTROL FUSE. IF FUSE GOOD PROBLEM IS IN THE SERVO MOTOR THE CRUISE CONTROL MODULE VACUUM PUMP AND CLUTCH VENT VALVE THE BRAKE VENT VALVE AND VACUUM SIGNAL AMPLIFIER.YOU HAVE TO TAKE CAR TO DEALERSHIP THEY HAVE EQUIPMENT TO FIX IT.

Sometimes the issue is with the mechanical vacuum pump off to the side of the ABS/ESP module. It looks like a round silver canister. This issue is all over Google with many possibilities but the one I copied is most common.

Either one of the vacuum hoses has popped off or there is a leak in the system. The system uses a vacuum pump to push/pull air through hoses connected to actuators in each door..
Have someone activate the system while you listen in the trunk for the pump, find it and see if one of the hoses has fallen off there.

The cable was probably not reattached to the throttle body, or the wiring for the cruise module was not plugged back in. The VW/Audi cruise control system does not use engine vacuum, it uses it's own vacuum pump. Vacuum runs from the pump/control module to the vacuum reservoir that pulls on the throttle cable. The is also another vacuum line that runs to the brake pedal, which is a safety feature (press the brake pedal and the vacuum to the vacuum reservoir is instantly cut, releasing the throttle and disengaging the cruise control.)

Here you will find the replacement of the wiper motor for Audi A4. Maybe similar for Audi A3! First you must diagnose your problem. 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. Success!

you might be looking at an air suspension pump. it is not designed to work for long periods of time.

This solution is 6 months after, so you've probably fixed the car, but here goes anyway.
The fuel system at engine must be free from vacuum leaks, to work.
Replace the hose. You won't hear the pump until the engine turns over....and then there's too much noise to hear it! No gas to motor is usually the fuel pump relay. Pumps don't fail very often.

It sounds like the vacuum pump has gone out. The locks are vacuum-pump operated, and they're known to eventually fail on these and VW cars. Check that out - in my 99, the unit is in the trunk, passenger side. You have to remove the storage well between the wheel arch and the taillight, and pull the carpeting back, and the unit is down there just a bit below floor level.