HI Everyone I have a 2008 Dodge charger RT with the 5.7 hemi, this morning I remote started the car and came out and it was making a slight whistling sound, so I thought maybe it had something to do with the alternator I had replaced. So I dismissed it.

Got in the car , it was a bit cold so I turned the heat on, but kept blowing cold air as if the A/C was on.
Checked engine temp and needle is in the middle of the gauge.
Next I noticed that when the car is driving at higher speed the heat does come out but as soon as I am at a stop or idling cold air comes out.

Does anyone have a clue as to what is going on?

 

Low on coolant. I suspect your water pump is leaking.... Verify that before spending money.

 

Thanks for your input, I didn't think it was low coolant because I had an oil change and the topped up the coolant about 1 month ago. But I checked and coolant was low so I added some and heat seems to be working again. But I think I might have a small leak. Will confirm by putting cardboard under the car over night.

 

The oil change place won't fill the radiator, they will just top off the overflow tank..... so, pull the radiator cap when the engine is stone cold, and see if it is indeed full. (providing your cooling system works that way...... too many different designs to keep track of these days. )

 

thanks for the reply. I checked and I dont think there is a radiator cap. So what i did is top up the overflow and will watch to see if that goes down. Then keep topping it up. But after topping up the overflow tank. Heat seems to be working. I just hope there is no small leak somewhere.

 

thanks for the reply. I checked and I dont think there is a radiator cap. So what i did is top up the overflow and will watch to see if that goes down. Then keep topping it up. But after topping up the overflow tank. Heat seems to be working. I just hope there is no small leak somewhere.
sorry for double post.

 

Pressure cap is on the overflow tank. It's kinda less of an overflow tank and more of a head tank.