Heater Core Replacement
 

Just bought a 1998 Boxster and have been running through a lot of maintenance items to make sure it is running well. Have had a lot of luck using this forum for everything so far.

The one issue the car came with is that I get the smell of antifreeze in the cabin whenever the HVAC is on. Does not matter if it is heat, fan, or A/C, if air is coming through the vents it has antifreeze smell.

In general, I believe that the only source of this would be leaking heater core. Would you agree? Does that make sense on Boxster? I read that Boxster does not regulate the flow of coolant to the heater core, it opens flaps allowing the air to pass through heater core box to regulate temperature. If that is the case, does it make sense I get the smell even with A/C on?

Assuming it is a leaking heater core, does anyone have a DIY/Tutorial on replacement of heater core? I have not had luck finding one. All the threads on different forums either had dead links or missing photos. From what I understand, I need to remove battery, wiper assembly, and then I should be able to access the heater core. Is that right?

Thanks!

Hello and welcome to the forum! I was able to find a guide/steps on the heater core replacement. Hope this helps you out a bit! Please let us know if you have any questions or if we can assist with any part needs.

1. Check whether the coolant shutoff valve is open.

2. Fill with coolant up to the bottom edge of the filler neck.

3. Run the engine at idle speed and top up with coolant until no more coolant flows into the cooling system when the engine is revved moderately. (Coolant level now at lies lower edge of filler neck.) The coolant temperature must not exceed 80°C; proceed directly to the next work step if necessary.

4. Close reservoir and warm engine up to operating temperature at a speed of -2500 rpm until the thermostat opens after approx. 10 minutes (coolant temperature -90°C).
Check: The radiator supply lines and return lines in the front wheel housings must be hot.

5. Allow engine to run an additional 5 minutes at ~ 2500 rpm. Every 30 seconds, briefly rev up the engine to -5000 rpm. RPM surges are important for proper bleeding.

6. Allow engine to run at idle speed until any activated radiator fans switch off again. Then switch off the engine. Open reservoir cap with extreme caution until the reservoir is de-pressurized (danger of scalding!).

7. Top up coolant expansion tank until level reaches lower edge of filler neck.

8. Reposition bow on bleeder shutoff valve, Unscrew oil cap.

9. Put on cover and body seal. Screw on both caps.