Ok - I have an 87 IROC 350TPI auto. WE just pulled the Intake manifold (among other things!) off to fix a leak. IM wound up having to go to machine shop, but came back looking great. We did a full intake gasket set, some new thermostat bolts, etc. Car now runs fine, but when I turn on the heater, it smells like anti-freeze inside the car. Especially when I turn on the defroster! Now it did NOT do this before we changed this stuff out. And the heater still works, it just smells. No leaks on the floorboard. Did we mis-route a hose or something? We also changed out a freeze plug that was leaking on the drivers side. What on earth did we DO to it?!?!? I really REALLY don't wanna change the heater core... Any help would be REALLY appreciated!

 

i'd say give it time to burn off and then start to worry about it. if it has had time to burn off there really isn't any way to mess it up as long as you don't have a leak, the anti freeze should be on the inside of the lines reguardless of where you put them or routed then

 

Pretty easy to lean on one of the heater hose nipples or otherwise do something careless, and break their solder joints where they attach to the heater core. Or, could just be a coincidence.

Make sure the hose clamps are tight, because if they leak, coolant wil run into the car along the nipples. If all that is good and it keeps doing it after a couple of days, the core is probably wacked.

 

Does the car still have an intact hood/cowl seal? If not, you may be getting odors from the engine compartment drawn into the air intakes, and blown through your cabin:



If that's all good, place a piece of plastic in the passenger side footwell to keep the coolant out of the carpet and insulation, and place a newspapaer on top of that to make any drips apparent. You may be replacing a heater core soon whether you'd like to or not. Actually, it's not that bad a job. I had done two on my '86 in 34,000 miles) but haven't had any problems since I changed to DexCool, and it now has 48,000 miles (typed while knocking on wood).