Why do I smell burning coolant through my truck vents?

[mocha42]

I smell coolant through my 98 rangers vents sometimes, I have a coolant leak, my truck also idles weird which makes my check engine light come on. What could be the cause of this?

 

[g168]

your heater core is leaking, look at carpet under glove box see if wet

 

[StephenC]

I too suspect the heater core, because it blows air over the core, which is filled with antifreeze. However, sometimes the obvious answer is not right. A coolant smell can be inducted from leaking coolant on the engine, either via the head, a hose or the waterpump. Rarely a crack or leaking freeze plug...how cold has it been? If below the coolant protection it could have popped a plug or cracked the radiator.

 

[DreSnark]

I imagine that the burning coolant smell is related to your leaking coolant. Just a hunch.