My '97 Ram 1500 with 5.2L (318) V8 takes a long time to warm up on cold days. Where my car will come to full temp in a mile or two my truck can take up to 5 or 6 miles to finally get to full temp when it 10* to 20* F . Once up to temp the heater will almost bake you, temp gage shows just past the 200* mark. I would think if the thermostat was stuck open it would never get that warm on a cold day. I can smell the slight "sweet" smell of anti freeze coming from the heater ducts, no fog just the slight smell; but can find no leak or loose any coolant . Any thoughts ? -Thanks

2 things come to mind 1) your thermostat is bad and 2) your heater core has a leak. If your replacing both of those you might as well replace the radiator hoses.

How many miles? Probably a good time to replace the water pump as well.

96,600 mi.

May have a cracked head or bad head gasket.

first thing change your thermostat ,sounds like its stuck open ,also clean your heating core ,blow dust out , if your not loosing coolant you don't have leak ,

If it's taking forever to get warm, your thermostat is likely not closing all the way, allowing some coolant to circulate through the radiator even with the engine cold. Replace the thermostat and see what happens. If you're smelling coolant, you have a leak somewhere. It may be a tiny leak that dries up before it hits the ground, but that smell doesn't come from nowhere.

I'll add a different twist to your problem, bore you start the pickup remove the radiator cap , start it up and watch what happens normally when the thermostat opens the antifreeze will start moving this may take awhile .

As for the heater not working the best after it's warmed up to a operating temperature touch the heater hoses that go to the firewall they should be warm or hot ( within reason ) to the touch there can be air lock so the antifreeze isn't circulating through it properly.
If not loosen the clamp and carefully remove the hose until it's mostly antifreeze not air so to speak.
This should get the air out of the system on older outfits with a slide heater temp control you could slide that back and forth and sometimes get the same results.

As I'm sure you know put a pan under where your working to catch any spilled antifreeze and flood dry is your friend.
I hope this helps let us know what you find.
Allan

May well have the WRONG thermostat installed.

I had an S-10 that would start to warm up when i reved it up. The fins were wore off on the water pump. It would cool down when reved up too

That was confusing. I should have said it would blow heat when reved and also the temp gauge would show the motor cooling when reved.

Fill the radiator with water rev it up if it shoots a stream of water out the cap hole it's the heads or the gasket. If not watch the water it should sit there for a bit then cycle then stop again if it rushing all of the time it should be the thermostat stuck open then.

For the price of a thermostat and gasket/O-ring, I would replace that and go from there. Like BigBob said get the correct temperature thermostat, most likely 195 degree.

I had a `98 which I bought new. 5.9l (360 cu in). 5-6 miles to heat up to full engine temp was normal at those temps. When the engine worked hard (accelerating) you got an extra blast of heat. What you describe seems to me to be normal except for the antifreeze smell. That sounds like a heater coil leak.

Try a thermostat, nothing to lose and go from there.

Cheapest thing first, just replace the the thermostat, looking or feeling for it can be just as far off as a guess, just replace it cheaper in the longer run time and dollar wise.

You can have a leak in your radiator with out leaving any fluid around, When it gets to pressure and you have a cracked seal cap it can throw steam out and you will lose fluid that way. My jeep is doing that now, you will notice a antifreeze smell when stopped any where or after your parked.

If your seeing a mist or a strong odor instead the vehicle of antifreeze, your heater core is leaking, or a line to it inside the vehicle is leaking, end of story there.

Burping the lines probably is not necessary if this has just developed, thats done when you have had to take all the fluid out for engine work or total fluid replacement, again more likely the thermostat. Unless you have done some sort of radical movements in the vehicle as in rock climbing or tipping the vehicle off canter a long ways. Evaluate your first notice of the actions of heating up and cooling to help narrow this down.

Water pump could also be failing and need extra R's to make it make up for the failure, you can also notice smells of fluids when this happens as they have a seep hole on them to let one know of pending failure, check around the pump for any moisture contacts or showings.

Only really four things to make that smell active outside the system, water pump failure, leaks in transfer system, thermostat or the radiator leaking.