Ok, let me start from the beginning. I just replaced my alternator about a week ago. It's been real cold out lately and I've been needing to jump start my car because my battery. i have a brand new battery also. Anyways, I work overnight and when i was leaving this morning, my car was dead. I had a co-worker jump start it and on my way home, my temp gauge started to go into the reds. I pulled into the nearest gas station and popped the hood open. There was a lot of steam coming from the coolant reservoir cap. My vents were blowing cold air even when it was set on hot. Someone nearby said they were for sure it was the thermostat. I was just wondering if you guys could verify that for me.

Not exactly so true.

First I assume coolant level is okay.

You have a thermostat, if it sticks open the car will take forever to heat up if it does, and you will very poor heater performance.

If it sticks closed, the vehicle will overheat, but you will also have heater operation. You say it was no heat.

So it cant overheat, and you have no heat out of the heater.

Still following me here?

When the thermostat opens, it simply allows coolant flow to the radiator. When closed it doesnt circulate into the radiator, but does everwhere else, heater core, block. ( except on 3.5 Nissans than it only circulates in the head and heater core, because it uses two thermostats, different topic though)

In your case I would be more looking into the water pump failing, if the impellar breaks, it will cause no heat, and the vehicle to overheat. Of the belt broke, I'm not sure what engine you have, if it timing belt driven, or drivebelt driven.



As far as your starting issue goes, this you would need a Midtronics battery/charging/starting system analzyer for.
The shop I work at for $59.95 will tell you what is wrong with your vehicle, using that analyzer, cheaper than what you just spent on a battery and alternator.
Something just came to mind, not sure if this is even possible, if your water pump is leaking, onto your drivebelt, it will cause belt slippage, which could your vehicles charging system not to work correctly. Just a though, but again, no clue how your engine drives the water pump.

good luck, hope this helped






- 2004 Cavalier - 124k, owned since new

Sounds to me like you don't have enough anti-freeze in your coolant and it froze up. That will make the engine run warm but you'll have no heat, because of no water circulation.

Joe Wilson is "spot on"...