Just replaced my leaky 225k heater core in my 1998 C70 with an aftermarket unit from FCP. This was the last plastic piece left in the original cooling system and it's been leaking for a couple months now.

The new core went in yesterday and sealed up nicely with the O rings supplied in the kit. I ran the car for a while to burb out all the air and enjoyed the warm air and distinct lack of coolant odor.

However. I started the car up this evening and now there is a horrible plastic odor from the entire heater system. It's not burnt plastic... more like something being heated up for the first time. It's one of those odors that you "taste" and it's pretty vile.

I'm hoping that this noxious emission is a transit coating burning off the core and that it will dissipate soon.

If not... then wow... I've got a problem.

Any thoughts?

Amazing. You have all of the bad luck! Yes, a transit coating will do that. Can you leave the driver's window rolled down at night, just to let the car air out?

I hope the core isn't touching the plastic housing.

Klaus
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My advice is free, so you got what you paid for...

Yeah, 2012 isn't looking so great for my car. My rebuilt ABS unit seems to be failing and the new heater core turns out to be a chemical warfare device.

The car airs out okay, but as soon as the heat comes on the noxious odors emanate. It's not a melting plastic smell... it's something else much more "chemical-like" The core fits in there pretty tight, and even it it were touching (which I think is unavoidable) that heat shouldn't be hot enough melt plastic

I just ran it hard on the highway for about 1 hour. It was bad. It might have dissipated a little bit but it's still coming out strong enough to make me want to gag. Drove at 70 mph with the moon roof open and the windows cracked and the outside air vent on just so I could breathe.

She's airing out in the carport now. My drive to work tomorrow isn't going to be too enjoyable - but at least it's only about 12 minutes away...

One thing is for sure, that smell wasn't there with the old core and definitely wasn't there yesterday when I first pumped hot air out of it.