When heater is on i smell coolant

It sounds like you have a bad heater core. It's the small honeycomb looking thing in your heat duct. It's best to get it replaced before winter because it will in time leak all over the place, before it gets better.

If their is coolant dripping from the heater then the heater radiator or pipes need to be replaced if you have the smell and but no coolant dripping then the leak is minor and the heat or the radiator evaporates the coolant so radweld solution or simular should fix. In both cases it is the evaporating coolant that is making the smell. Cheers

Hi

This is caused by a leak in either the heater core itself or the hoses connecting to the heater core.

Rust and corrosion can clog the tiny passages in your heater core. Sometimes the block becomes so severe that pressure builds up in the heater core causing it to spring a leak of coolant - enough to give off the smell you describe.

You can find examples of the heater core at this link
http://www.autopartswarehouse.com/shop_parts/heater_core/dodge/ram_50.html

Solution: Replace heater core or hoses depending on what you find.

Hope this helps. Please do rate this answer. Many Thanks.