Audi A3 - Heat output too low | HELLA
Audi
A3
Model years 1997 to 2003
All engines with cast-iron cylinder block
If a customer complains about the above error, this could be caused by contaminated engine coolant.
Such contamination (rust, metal particles from the cast-iron block) blocks the small openings in the heat exchanger preventing flow.
In this case, proceed as follows:
- Drain the coolant from the engine.
- Remove the thermostat housing, remove the thermostat and refit the housing.
- Fill the cooling system with fresh water and HELLA cleaning agent for cooling systems 8PE 351 225-841.
- Vent the cooling system.
- Warm up the engine. Set the heating to maximum and then let the engine idle for 10 minutes.
- Turn off the engine and leave it to cool.
- Drain the fluid from the system.
- Refill the system with clear water and vent the system.
- Warm up the engine.
Check heat output. If output has not improved, the heat exchanger must be replaced.
- Drain off the fluid again.
- Refit the thermostat. In such cases, it is recommended that the thermostat is also replaced.
- Fill the cooling system as per manufacturer’s instructions (correct coolant and correct mixing ratio).
