Ok I got a 96 civic hatch cx. Ive had the car for a little over a year and ever since I bought it the heat smells real sweet when its first turned on then goes away. I have had no signs of leaky heater core and it didnt start over heating until this past winter. I changed the thermostat in Jan/Feb ish and everything has been fine as far as overheating up until a few weeks ago. When the car is not moving it overheats. As soon as I place my foot on the accelerator the needle drops back down to normal range. The fan works and there is no sign of water in my oil so I highly doubt its a head gasket. The water pump is relatively new. The person I bought it from has all maintenance receipts and it was done about 60k~ miles. The car has just under 160k on it. Any ideas as what could be going on?

 

Have you tried a thorough bleed of the cooling system?

Bleeding the cooling system:

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push the dash heater lever/**** to MAX heat.

3) Follow the directions in the diagram below (skip the bleed bolt step as your engine does not have one):

 

Well I bled it good when I changed the thermostat but I guess I can give it another try.

 

Is the overheating associated with a loss of coolant? For example, is the radiator cap possibly unable to hold proper pressure?

Another possibility is that the heater core and radiator are clogged with debris. Have you tried flushing the cooling system and heater core?

Any white smoke in the exhaust?

 

no white smoke so its not burning water. Im sure its something stupid I just want to pick everyones brain so I can cover all basis. The car has not been flushed since Ive had it nd could probably use one.

 

The sweet smell (coolant) from the heater also suggests a pinhole leak in the heater core.

 

hhmmmm??

 

really? I have another to put in i just dont feel like ripping out the dash

 

try taking the thermostat out and run it with out it see if it still happens