Its not very easy to replace heater core, and it takes lots of time and lots of parts disassembly is required.
Replacing your heater core is pretty involved. The book time is 6.6 hours plus time to evacuate and recharge the a/c. The heater case assembly has to be removed and disassembled to replace the heater core.
Here is the procedure.
First you need to remove the instrument panel.
Before beginning repairs on the electrical system:
Obtain the anti-theft radio security code
Switch off all electrical consumers
Switch ignition off and remove ignition key
Disconnect negative (-) battery terminal
When disconnecting and reconnecting battery terminals, observe all applicable Notes and torque specifications, as well as instructions on performing OBD program and electrical system function checks.
Instrument Panel, Removing And Installing
Disconnect vehicle battery.
Remove center console.
Remove driver side airbag unit.
Remove steering wheel.
Unscrew 2 Phillips-head bolts - arrows -.
Remove upper trim for steering column switches - 1 -.
Unscrew Phillips-head bolts - arrows -.
Remove hex socket head bolt - 1 -.
Loosen height adjustment for steering wheel - 2 -.
Remove lower trim for steering column switch - 3 -.
Remove socket head bolt - 1 -.
Disconnect harness connectors - arrows - from steering column switch.
Remove steering column switches - 2 -.
Pry off cap - 1 -.
Remove bolts - 2 - and - 3 -.
Unclip lower A-pillar trim on drivers side - 4 - from sill trim and remove.
Unclip cover - 1 -.
Remove bolts - arrows -.
Remove storage compartment on drivers side - 2 -.
Disconnect harness connectors from light switch - 3 - and from headlight beam adjuster - 4 -.
Slide cover - 1 - upward and clamp using equipment (e.g. screwdriver handle) - 2 -.
Remove four bolts - arrows -.
Remove cover - 3 -.
Remove two bolts - arrows -.
Remove instrument cluster.
Disconnect harness connectors.
Radio Removal Tool 3316 is required for removing the radio. Radio Removal Tool 3316 consists of two equivalent individual parts.
Slide Radio Removal Tool 3316 into release slots - arrows - until they engage.
Pull radio out of instrument panel using grip rings on removal tool.
Radio Removal Tool 3316 must not be pushed to the side or tilted during procedure.
To remove removal tool from radio, press in locking lugs on side of radio.
Disconnect harness connectors.
Unclip trim around radio
Remove 8 bolts - Pull out cover for center instrument panel
Remove five bolts
Disengage three clips - arrows - using flat screwdriver - 1 -.
NOTE: The locking mechanism is located in the upper area of juncture between vent and instrument panel.
Keep vent - 2 - under load while doing so, to prevent disengaged clips from engaging again.
Pull vent - 2 - out of instrument panel and disconnect harness connector - 3 -
Remove hex bolts - arrows -.
Disconnect harness connector - 1 -.
Remove instrument panel.
Observe all A/C refrigerant system safety measures.Service refrigerant system using Kent More ACR 4 or equivalent.During servicing, all couplings, fittings and related fasteners must be torqued to specifications.
Discharge refrigerant system.Drain engine coolant. Remove instrument panel as described above.Remove coolant hoses at heater core.Note Installation orientation of coolant hoses -A- (inlet and outlet) in engine compartment.Clamp off both coolant hoses to heater core using 3094 hose clamps (or equivalent).Release both coolant hose clamps using suitable pliers and pull hoses off from heater core inlet and outlet.Seal off inlet and outlet at heater core to prevent coolant from escaping.Remove refrigerant lines at evaporator.
Remove screw -3- (15 Nm) .
Gently rock flange with refrigerant lines -2- up and down until they release from evaporator.
Immediately plug open connections on A/C components and lines to prevent dirt and moisture contamination
Always replace both O-rings -1-.
Carefully pull out and remove complete housing -1- from vehicle.
Hopefully this will help you. If you don't feel confident in your technical ability I would not recommend trying this repair.Get it done by proper garage mechanic.
For more car related problem troubleshooting:---
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