Dear Jim,

I get up for work very early in the morning. The other day it was chilly where I live, so I turned on the heater in my 1995 Ford Escort. After driving for a little while, I noticed there was some steam coming from the heater vents and I could smell burning oil inside the car. I checked the oil level and it was fine, but I took the car in for an oil change anyway. They said my radiator coolant level was low, so they added some antifreeze. But the burning oil smell is still there when I use the heater. Do you know what the problem is here?

--Ray Meador

Yeah, brother, it sounds like you're not really smelling burning engine oil from the heat vents, you're smelling coolant. When you turn on the heater in your Escort, something called the heater core comes into play. It's like a little extra radiator that circulates hot water from the engine and uses it to heat up the air that a fan blows into the passenger compartment. If you're getting that sweet coolant smell coming from the vents, it means there's a leak somewhere in the heater core. The air that's being blown through it is picking up the vapor from this leaked water/antifreeze mix and sending it into the passenger compartment.

With the mornings getting cooler now, we're going to be using our heaters more and more. Get this heater core problem fixed right away, bro. Sure, it's irritating to get a coolant smell coming into your car, but on top of that, it's not a good idea to be exposed to antifreeze or antifreeze vapor for any length of time.

Tip of the Week:

With the cooler months coming on, remember to get your vehicle's thermostat checked. Some of you may have even had the thermostat pulled out this summer, especially if you encountered any overheating problems. Here's the thing: If that thermostat is stuck open or has been removed, it's going to make trouble when you use your heater later on. The engine cooling system will end up holding on to all the coolant, not allowing enough of it to get rerouted to that heater core -- exactly the place it's needed when you're trying to warm up your car's chilly interior.

Buffalo Jim, owner of Allstate Auto & Marine Repair in Las Vegas, writes a weekly column. Send your automotive questions to him at buffalojim@lasvegasniftynickel.com. If Jim picks your question to answer in Nuts & Bolts, you'll also be the proud recipient of a deck of official Buffalo Jim playing cards, presented in a classy, tin box bearing his hairy image