How do you change heater core on a 98 Pontiac Grand Am?

Answer 1

Tools Required:

-Channel-lock pliers

-driver with 7/32" and 7mm bits

-phillips screw driver

-this document

-patience

The following steps are how I went about changing my heater core:

1. Drive the front of the car up on ramps, or jack it off the ground

2. Disconnect the negative battery cable

3. Open the cap of the overflow tank (to release pressure be careful!)

4. Inside the car, on the passanger side, take out the kick panel. There are two quarter turn plastic knobs just under the glove box, turn these, and pull the kick panel towards the seat

5. Take the bulb and socket out of the kick plate by turning it 1/4 turn, and there is a harness clipped onto the kick panel, just pull it straight up.

6. Remove the kick panel on the drivers side using similar procedure as the passanger side, (this is not necessary to remove, but it helps)

7. You DON'T need to take out the dash or center console. All you need to do is loosen the dash. In front of the gear shift lever, you will see a storage cubby hole (right under the climate controls), use a phillips screw driver and remove the two screws that hold the trim to the dash. Then pull on the trim to release it from the dash (spring clips). There is no need to pull the trim all the way off the dash, you just need to gain about 1-2" of space to remove the air vent cover.

8. Next take a 7mm (not sure what it is in imperial) and find the two screws that hold the air vent cover for the floor heat on. They are two silver screws, one on the driver side (about 12" up from the firewall) and one in the same location on the passanger side.

9. Remove the tubing on both driver and passanger side that are connected to the air vent cover, just twist and pull to get it off

10. The air vent cover will 'fold up' once you have the two screws out, the fold will happen in the middle of the cover. then take the top end (nearest to the gear lever) and pull it towards the passanger side footwell. On the air vent cover end nearest the firewall, there is a molded duct on the cover that goes into the floor, you will have to lift the back end of the cover out of the floor.

11. Locate the screws holding the heater core cover on (7/32"). On my car there were 5. 3 by the fire wall (one on either corner and one in the middle that you have to find by feel, because you can't see it). Then there are two higher up towards the center console.

12. Now go under the car, and remove look behind the engine, in the center of the car, by the firewall, you will see two rubber hoses going into the fire wall. Towards the passanger side of those hoses you will see a rubber tube that is bent 90 degrees. Out of this tube flow the water (condensation) from your a/c, and if you have a major heater core, your coolant will flow out from here too! Remove this tube by giving it a good pull.

13. Now its time to get messy. I didn't drain my coolant, and I don't think its necessary. Make sure you have a catch basin (like where you catch your oil in when you do an oil change). Make sure the engine is cold when you do this step....otherwise you will get burning coolant all over your arms! Remove the driver side hose first. I used channel lock pliers to squeeze the clamp together, and twist, wiggle and slide the clamp towards the engine (slide it about 4-5"). Repeat this for the other hose as well.

14. Place catch basin under the hoses, and pull them off one at a time (I did the driverside first). In total I lost about 6 litres or 7 quarts of coolant.

15. Now that there are no external connection on your heater core anymore, go back in the car, and remove the heater core cover.

16. To remove the heater core cover, takes a bit of handling. You need to pull it out towards the seats, but on the driverside, you need to push the cover down a bit, while pulling it out. I pulled it out through the passanger side foot well.

17. You should now see your heater core sitting there. There are two brackets holding it in place, one on top end and one on the bottom end. Remove the brackets and then pull you heater core straight out. Try to tip the pipes that come out of the firewall up as soon as you pull it out, to prevent the coolant from draining out of the heater core all over your carpet!

18. Compare the old heater core to your new one, and make sure they are the same dimensions.

19. Put the new heater core in, making sure the cooling lines go through the firewall, and replace the mounting brackets to hold it in place.

20. Crawl under the car and now comes the fun part. Slide the hoses back onto the lines, and slide the clamps back. This may sound weird, but the easiest way to do this is either to take the old clamps off the hoses first, and put on the screw driver type hose clamps (I recommend this), or you can do it the way I did, by sitting....er...laying under the car for 1/2 and hour trying to slide these spring clamps back on.

21. Replace the rubber drain tube, just slide it on!

22. Go back inside and replace the heater core cover. NOTE: I had my temperature dial set to the cold position, and when I got it all back together, I couldn't turn my dial!! Put the dial in the middle somewhere between hot and cold, THEN put everything back together.

23. Replace the air vent cover with the two screws, and put the tubes back on

24. Clip the dash trim back into place and put the two screws back in.

25. Replace the kick panels on both sides. On the passanger side there is a hook near the fire wall, that the kick panel needs to rest on, so make sure you what how you put it on.

26. Clear all your tools and catch basin from under the car. Start it up and drive it down the ramps.

27. By now the low coolant light will be on. Fill up the resevoir while the car is running with 50/50 mix of DEX-COOL coolant (the red stuff) and distilled water (avoid the use of tap water, because it contains calcium and other junk that will cause build up in your cooling system).

28. Once the resevoir is full, and doesn't drop anymore, look in at your gauges, and see if the idoit light is still on for "low coolant". If it is, and your tank is full, hit the side of the resevoir with a screw driver handle a few times. The way the sensor is mounted in the tank, it allows for an airlock to occur, which could take a day or two of driving to get rid of, but the good ole' screwdriver does it in a few seconds. Check the gauges again, and the light should be off now.

29. That's it!! Keep a mixed jug of coolant with you, because there is a possibility that there is an airlock in your cooling system, that will work its way out over a week of driving, so you may need to add fluid for the first week or so as necessary.