Bubbling Coolant Tank + Heater Core Leak - Related or Coincidence?

[Chipps]

Hey everyone,

Got home tonight and heard a bubbling sound coming from my coolant expansion tank. I know a lot of folks here recommend swapping the radiator cap first (cheap and easy fix), but there’s a twist…

I’ve also got a confirmed heater core leak that I’ve been putting off until I can get a few solid days off work.

My question is, could the heater core leak be what’s causing the bubbling in the expansion tank? Or am I more likely dealing with a cap/pressure issue?

Would love to hear if anyone’s had the same symptoms and what fixed it for you.

 

[Ashim]

The heater core leak keeps the system from being pressurized, reduces the boiling point, causes the bubbling in the tank. Bypass the heater core until you have time to fix it.

 

[Chipps]

The heater core leak keeps the system from being pressurized, reduces the boiling point, causes the bubbling in the tank. Bypass the heater core until you have time to fix it.

Thanks. That seems the way to go. Only problem I have is sourcing a heater core for a RHD. I’ve believe the part number is 4874046.

Found a guy on eBay who’s had some made and pressure tested. But they’re $475! And don’t ship to the UK, so I gotta use a third party shipper .