one day my car starts to run hot and i pull over to find that there is no coolant in my reservoir or my radiator. so i fill up both with coolant and start to drive. when i'm cruising on the freeway my temperature is low but when i'm in neighborhoods driving at low speeds my temperature starts to raise up again. any idea what's going on?

 

Year and make of vehicle?maybe water pump..prob head gasket..is there coolant leaking on to the ground?

 

sorry 1995 honda civic dx hatchback, there's a really slim chance there there IS coolant leaking, but i don't think so. also, i don't know if this helps but my exhaust is giving out a little white smoke, and if i'm correct, i think that means there's water somewhere? again sorry, i'm new to this

 

If there isn't an obvious leak, you'll want to pressurize the system with a radiator pressure tester. This will make smaller leaks show themselves and also tell you if the system holds pressure.

The coolant has to be going somewhere. If it isn't leaking externally, it's probably the headgasket. And yes, white smoke from the exhaust is a sign of coolant getting burned once it passes the headgasket.

 

hopefully i can get my head gasket replaced this week. out of curiosity, is there an explanation as to why the reading on my temperature gauge stays low when i'm cruising on the freeway, and why it runs hot in small neighborhoods? i'm guessing it has something to do with the cooling system?

 

Cool at freeway speed but overheating at lower speeds, [small neighborhoods] is an indication that rad fan(s) is not working. 94

 

Sounds like you may have a leak and a fan not working. Driving fast down a free way circulates the air fast enough that the fan is not really needed.

 

A head gasket will over heat a car even on the freeway.
Like Fcm said check fans for operation.

Fill up fluids
Start car
Watch temp and fans back and forth.
If the temp guage goes past Operating temperature and your fan does turn on. You either have a dead fan or a dead fan switch located under your intake manifold behind your block.


Best of luck