Heater Core Case: Service and Repair
Heater Core
Special tools, testers and auxiliary items required
• Drip Tray For Shop Hoist (VAS 6208)
• Hose Clamps up to 40 mm (3093)
• Compressed air gun, commercially available
Removing
- Disconnect the battery.
- Place (VAS 6208) under the engine.
Contact with hot engine coolant can cause severe scalding.
Coolant temperature can be above 100 °C (212 °F) with a warm engine. The coolant system is under pressure.
If necessary, reduce pressure and temperature before repairs.
- Clamp the coolant hoses - 1 - using the (3093) and then remove them from the heater core.
- Insert one section of hose - A - and of - B - on to both connections to the heater core.
- Hold a container - C - under the hose of lower connection - B -.
- Using a compressed air gun - D -, carefully blow coolant out of the heater core (into container - C -) via hose - A -.
- Loosen the bolt (6 mm inner hex socket) - 1 - on the connection flange between the heater core connections, but do not remove it.
• This allows the coolant pipes to move for removing the heater core.
- Remove the driver side footwell trim panel.
- Remove the driver footwell vent. Refer to => [ Left Footwell Vent ] Left Footwell Vent.
- Remove screw holding drivers side center console side cover. Refer to Center Console in
- Remove the bolts - 1 - (9 ± 1.3 Nm) and - 3 - (1.5 Nm).
- Remove the heater core cover - 2 -.
- If the vehicle is equipped with a diesel engine, unlock the connector clamp for the auxiliary heater to allow harness to move aside.
- Cover the carpet the in area under heater core with waterproof foil and water absorbing paper.
- Remove bolts - 1 - from the hose clamp for the - 3 - coolant line - 2 - (2 Nm).
- Slide the hose clamp - 3 - toward the rear off the coolant line- 2 -.
- Disconnect the coolant lines - 2 - slowly from the heater core - 4 -. Collect any flowing coolant with a suitable container.
- Remove heater core - 4 - from the heater and A/C unit - 6 -.
• Replace the seals - 5 - before installing the heater core - 4 -.
Installing
Install in reverse order of removal. When doing this, note the following:
- Check seals - 1 - and - 2 - on the heater core for damage.
• An incorrectly glued seal can roll up into heater when sliding in the heater core.
• Cold air may flow past heater core if seal is damaged or not properly fitted.
- Inspect the heater core installation slot - 1 - on the heater and A/C unit for debris.
- Remove any dirt or coolant which has leaked out of the heater and A/C unit (for example, after removing a leaking heater core).
- Replace the seal - 5 - for the heater core- 4 -.
- Position the heater core - 4 - in the heater and A/C unit - 6 -.
- Connect the coolant lines- 2 - to the heater core - 4 -.
- Attach the hose clamp - 3 - at the separating point and tighten the bolts - 1 - (2 Nm).
- Install heater core cover.
• Coat the seals - 5 - with refrigerant oil before installation and before connecting them with the coolant lines- 2 -.
• Replace deformed hose clamps.
• Install the clamps - 3 - as shown in the illustration.
• Tighten the bolts- 1 - and then check to see that both hose clamps - 3 - are in their correct positions. The hose clamps must enclose the flange on the heater core and coolant pipe completely. They must not touch other components.
• Replace all the coolant after replacing the heater core.
• Check coolant circuit for leaks, pay particular attention to the connection between coolant hoses and heater core.
- Tighten the bolt - 1 - (6 mm inner hex socket) on the connection flange between the coolant lines for the heater core- 2 -.
- Make sure the seal - C - fits correctly inside the plenum chamber bulkhead.
- Seal flange for coolant pipes to heater core - A - and for expansion valve (to evaporator, only in vehicles with A/C system) - B - at pass-through of the seal - C - with silicon adhesive sealant if necessary (to prevent water from penetrating).
- Connect coolant lines.
- If equipped, install heat shield.
- Refill the coolant and bleed the coolant system.
- Install the driver side footwell cover. Refer to Storage Compartments and Covers under.
- Install left footwell (in the middle console). Refer to Storage Compartments and Covers under.
- Install footwell vent on the driver side. Refer to => [ Left Footwell Vent ] Left Footwell Vent.
- If equipped, install the knee airbag.
Observe the general safety regulations when working on airbag, belt tensioner, and battery cut-out units (pyrotechnic components).
- Connect the battery.