Sounds like its not a leaking heater core. My guess is two separate problems. A blower motor that is failing and an external coolant leak. Water leaks can really travel so I would just start running my fingers around every hose, fitting and hosing looking for some green/red. If that doesn't do it you can pressurize the system at rest and listen or add some UV dye.




George

 

Thanks a lot for your help George. I'll let you know when I sort it all out.

 

Two more thoughts on your coolant leaks. A spray bottle of soapy water when the system is at pressure is a good diagnostic tool and don't forget to check your freeze plugs.

George

 

5 more cents worth of a thought.

When the heater-core has been changed many people omit the foam/rubber gasket around the tubing passing the firewall. If the leak is in the engine bay onto the exhaust it may pull these fog/fumes in through there.

 

+1

George