How to replace heater core on 2005 Volkswagen Jetta?

Removal & Installation

2005 Jetta

1. Before servicing the vehicle, refer to the Precautions Section.
   
   NOTE

   Be sure to obtain the anti-theft code for the radio.
2. Disconnect the negative battery cable.
3. Remove facing wall in plenum chamber.
4. Place Drip tray for VAS6100 VAS 6208 under the engine.
5. Clamp off coolant hoses using hose clamps, up to 1.6 inches (40mm).
6. Disconnect coolant hoses to heater core.
7. Connect a section of hose onto upper connection of heater core.
8. Hold suitable container under the lower connection.
9. Using a compressed air gun, carefully blow coolant from heater core into container.
10. Remove bolt (6mm socket head) from connection flange between heater core connections. This allows the coolant pipes to move for removing the heater core.
11. Remove driver side footwell trim and left footwell air vent.
12. Remove screws and remove heater core trim.
13. Cover floor carpet in area below heater core with leak-proof foil and absorbent paper.
14. Open hose clamps and disconnect coolant pipes from heater core.
15. Remove heater core from heating and ventilation unit.

To install:

1. Install in reverse order of removal, noting the following:
   
   
   
   
   1. Check seals installed on heater core, only install a heater core with undamaged seals. An incorrectly glued seal can roll up into heating and ventilation unit when sliding in the heater core.
      
      NOTE

      If seal is damaged or installed incorrectly, cold air can flow past the heater core.
   2. Push heater core into the heating and ventilation unit.
   3. Coat sealing rings with coolant before installing.
   4. Insert sealing rings into connection on heater core.
   5. Ensure sealing rings are installed with the chamfered end facing the heater core.
   6. If hose clamps are deformed, replace them.
   7. Connect coolant pipes to heater core.
   8. Hose clamps must be able to be twisted slightly when installing onto the coolant pipes. Tighten hose clamps to 1.5 ft. lbs. (2 Nm).
   9. Check seating of both clamps after tightening screws, clamps must enclose the flange on heater core and coolant pipe completely and must not touch other components.
   10. Thread bolt into connection flange and while doing this ensure bolt is actually threaded into the mounting point intended for it.
   11. Check position of grommet in bulkhead for proper seating.
   12. Seal flange for coolant pipes to heater core and for expansion valve (to evaporator, only in vehicles with A/C system) at grommet pass-through with silicon adhesive sealant if necessary (to prevent water from penetrating).
       
       NOTE

       Sealing rings must always be replaced. If hose clamps are deformed, replace them.
2. After replacing heater core, coolant must be replaced completely.
3. Check coolant circuit for leaks, pay particular attention between coolant hoses and heater core.
4. Connect the negative battery cable.
5. Evacuate, charge and leak test the air conditioning system refrigerant.
6. Operate the engine to normal operating temperatures; then, check the climate control operation and check for leaks.

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Also see this link below for more details:---

How to replace heater core on Volkswagen Model?

http://vwrepairhelp.blogspot.com/2011/11/how-to-replace-heater-core-on.html

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For car AC related and Heater related solutions. You can refer the options mentioned below:---

Car AC Blows Warm Air ?

http://technoanswers.blogspot.com/2011/10/car-ac-blows-warm-air.html

How to test AUTO AC pressure?

http://howtobyme.blogspot.com/2011/10/how-to-test-auto-ac-pressure.html

AUTO Air Conditioning Troubleshooting?

http://technoanswers.blogspot.com/2011/10/auto-air-conditioning-troubleshooting.html

AUTO A/C COOLING PROBLEM?

http://technoanswers.blogspot.com/2011/10/auto-ac-cooling-problem.html

Fixing refrigerant leak?

http://howtobyme.blogspot.com/2011/10/how-to-fix-refrigerant-leak.html

How to locate Car AC Refrigerant leak?

http://technoanswers.blogspot.com/2011/10/how-to-locate-car-ac-refrigerant-leak.html

CAR AC INTERMITTENT COOLING?

http://technoanswers.blogspot.com/2011/10/car-ac-intermittent-cooling.html

What causes INTERMITTENT COOLING on Car AC system?

http://technoanswers.blogspot.com/2011/10/what-causes-intermittent-cooling-on-car.html

Car AC making Noise?

http://technoanswers.blogspot.com/2011/10/car-ac-making-noise.html

BAD ODOR ON CAR AIR CONDITIONER?

http://technoanswers.blogspot.com/2011/10/bad-odor-on-car-air-conditioner.html

How to Recharge Car's Air Conditioner

http://repairhelpcenter.blogspot.com/2011/10/how-to-recharge-cars-air-conditioner.html