BillBrasky

Having coolant leak constantly from my radiator, but no leaks visible under the car. I 'm starting to think its my heater core leaking, however, there are no wet spots on the floorboard. Im pretty confident it is coming from the heater core / hose because I have a coolant smell inside my car as well as a ton of condensation and moisture around the center AC vents and windows.
Just wanted to get any second opinions before I have to remove the whole dash to replace the core.

01MSMSXE10

To determine if your heater core is leaking, check out under the dash on the passenger side. You can pull the carpet back and see the lower pipe and should be able to determine if it's leaking.

My heater core is leaking and like you I have the smell of coolant in the cabin, condensation on the windows, and had a slow coolant leak too. I bypassed mine a few months back and never got around to doing the repair until now. Good luck.

Samson1971

Hi, Did you replace heater core? Do you have pics?
i must do mine asap 2006 is220d

01MSMSXE10

I didn't replace just my heater core, I had a broken blend door in my IS, I had to replace the entire HVAC assembly box, heater core evaporator core, and expansion valve. I didn't have to replace the last 2 but since I was already in that far, it makes sense to replace it all. It took me close to 14 hours to pull the dash, swap components replace broken items and reassemble the dash.

Sounds like you have a 2nd gen IS chassis. You may want to check out the 2nd gen forum to see what people are doing.

If I had to replace just the heater core, I'd opt for the less labor intensive way of cutting the is300 heater core pipes under the dash, installing a RX300 heater core (because cheaper and easier to find and it's the same size, I've confirmed), and using hose to mate the cut pipes for a factory ish install. You'll never see it, so who cares what it looks like.