Hello all. I'm a new member on here and am looking for a little feedback on a problem with my '00 GMC Sonoma. For the last little while I can smell an odor coming from my heat vents. It almost smells like maple sugar or something sweet. Though I'm pretty sure it's engine coolant, I'm not sure what the problem is. When driving with the heater fan off I can smell this, once I turn the fanon it diminishes. There aren't any traces off coolant in my driveway so I assume the hose isn't leaking. Anyone have any suggestions?

Heater core is seeping...A tuff repair on those.

Expect to pay around 250$ labor,plus a core and coolant