Audi A3 - Heat output too low | HELLA

Audi

A3

Model years 1997 to 2003

All engines with cast-iron cylinder block

Heat output too low

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).