Heater Core: Service and Repair

1985 Buick Century V6-231 3.8LSECTION Service and Repair
LESS A/C
Exc. 1983---88 Century & Cutlass Ciera & 1984---88 Cutlass Cruiser. For service procedures on 1983---88 Century and Cutlass Ciera, refer to models with A/C.
1. Drain cooling system.
2. Remove heater inlet and outlet hoses.
3. Remove radio noise suppression strap.
4. Remove cover retaining screws and cover.
5. Remove heater core.
6. Reverse procedure to install.

WITH A/C
1. Drain cooling system.
2. On all except diesel engine models, disconnect heater inlet and outlet hoses. On diesel engine models, raise vehicle and disconnect heater inlet and outlet hoses, then lower vehicle.
3. On diesel engine models, remove instrument panel lower sound absorber. On all models, working inside vehicle, remove the heater ducts, then the heater case side cover.
4. Remove heater lower outlet.
5. Remove 2 housing cover to air valve housing clips, then the housing cover.
6. Remove heater core retaining straps, core tubing retainers, then the core.
7. Reverse procedure to install.



RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.