Audi Q5/Q7: How to Replace Thermostat and Water Pump
Has your water pump died, leaving you and your engine overheating? This article will walk you through the steps of replacing it so you can get your engine (and your temper) cooled off.
This article applies to the Audi Q5/Q7.
Water pumps play an integral role in your car's cooling system, continuously pushing fluid through your engine block and cylinder head and back through the radiator for cooling. When the water pump is working properly, your engine stays cool and everything is great. When a water pump fails, your engine can quickly overheat and leave you stranded on the side of the road or worse, with a blown gasket. If your water pump is leaking or you are experiencing temperature gauge fluctuations, keep reading and we'll walk you through the process of replacing it.
Materials Needed
- New water pump
- Assorted Torx bits and driver
- Assorted common size sockets and ratchet
It's a good idea to also replace your thermostat if you are replacing the water pump. They are very inexpensive, so replacing it before it fails is a smart, proactive measure.
Step 1 – Replace the thermostat
If you have a supercharged model, you may need to remove the super charger to gain enough access to remove the water pump. Here is an excellent video detailing that process. In short:
- Remove the intake tube from the throttle body.
- The supercharger is bolted to the top of the engine, remove all of the Torx bolts holding the supercharger onto the lower intake plenums.
- Remove the miscellaneous vacuum tubes and wiring harnesses around the manifold from their clips and push them aside.
If you don't have a diagram of your belt system, draw one up on paper before you begin to make rerouting the belt easier later on. Loosen the bolts on the water pump pulley using a T10 Torx bit, but don't remove them just yet. Use a 16mm wrench to loosen the belt tensioner. With the belt loosened, go back and remove the three screws from the water pump pulley and remove the pulley. The water pump is held in place by seven T30 Torx screws. Remove those screws and pull the water pump out.
Figure 1. Loosen the screws on the water pump pulley. 
Figure 2. Loosen the bolt on the belt tensioner to release the belt. 
Figure 3. Remove the seven bolts holding the water pump in place. 
Figure 4. Remove the water pump.
Step 2 – Remove and replace thermostat
With the supercharger, water pump and pulley out of the way, we can finally reach the thermostat. It's located just inside the "V" of the cylinders. Look behind the location of the water pump pulley, on the top of the engine, and you will see a large black plastic housing, with seven T30 Torx screws, near the left-front cylinder inlet. That is your thermostat, and removal is as simple as removing the seven Torx screws and pulling straight upwards to remove the thermostat as well as its housing. There is a rubber gasket/seal on the thermostat assembly, so it might take some force to break the seal on it. With the old thermostat out, drop the new one in and refasten the seven Torx bolts.
Figure 5. Thermostat location. Follow the radiator hose if you can't find it. 
Figure 6. thermostat removed and bolt locations shown. 
Figure 7. Thermostat removed.
Step 3 – Install new water pump
Set the new water pump in place and reinstall the seven Torx screws. Reinstall the water pump pulley and bolts. Reroute the drive belt over the pulleys, using your diagram to ensure everything is routed correctly. Once the belt is in place, tighten the belt tensioner so there is a little slack. Push and pull on the belt to check the tension; If it moves more than 1/2", it is too loose. If it moves any less than 1/2", it is too tight. Once the belt has exactly 1/2" of slack, start the car and check for leaks and proper operation of the new pump.
Featured Video: How to Change Q7 Thermostat and Water Pump
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