Hi all, well my topic says it all. I smell coolant inside the cab when the heater is on, I inspected the core, no leaks and the floor is nice and dry. Why would I be smelling coolant? I also notice that the system is always blowing a slight amount of cold or hot air depending on the temp I set it at, if I switch it to the hot setting without turning the blower on, I smell coolant. Any thoughts? Should I still look at the core? I dont have anything wet on the floor.

Woops forgot to add, its a 98 v70 glt, and it loses about a 1/2 gallon of coolant every few days.

I had a coolant smell whenever the heat was turned on (blower or not), but upon inspection I could find no leaks, not even residue from past leaks that had dried. I wasn't losing coolant either.
The smell went away after replacing the heater core.

Your loss of coolant is indicative of a more serious problem if there really isn't any coolant leaking into the cabin. In addition to having a closer look at the heater core and piping (remove drivers side knee bolster and center console trim) you should have a close look at the rest of the system under the hood.

That is a lot of coolant to leak and not know where it is coming from. Check the hoses from the block to the firewall. Also check the cap for hairline cracks. Look at the sides of the radiator, use a paper towel to see if there is any coolant there.

The antifreeze is always flowing through the heater core, regardless of the temp setting. The reason you smell it only when you turn on the heat with the blower turned off puzzles me.
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My name is Klaus and I am a Volvoholic.

Sorry, I may have not expressed that clearly enough. The coolant smell is there if the blower is on or off and the heat setting is set on the red. The radiator was just replaced, my 1/2 gallon I just added may have been from trapped air finally circulating up. Im gonna try replacing the filler bottle, it may be leaking.

The easiest way to check the filler bottle is with a dry paper towel after getting the engine temp up to warm. Check the cap and the small hose at the bottom.
If there is no leak inside the cabin, the coolant smell could be coming from the engine bay. The rubber gasket along the shelf of the window cowling may not be completely sealed, it has a tendancy to shift and ride up allowing engine air to get sucked into the fresh air.
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My name is Klaus and I am a Volvoholic.

I had a small leak on my '97 850 on one of the heater hoses at the FireWall and was a slow leak and leaking on the Turbo and I smelt Coolent also without see a leak....

Makes sense! I will look at those hoses, the turbo is right there and probably ruins those hoses fast and the coolant disintegrates on the turbo without a drop hitting the ground.