If it has a thermo(electric) radiater fan, check that it is working, by connecting it directly to the battery, and if it works, it's probably not switching on when the temperature rises, so the thermo switch will be faulty.
Low coolant? Cooling fan not working? Radiator plugged or air flow restircted? Defective radiator cap?
300
Weak fuel pump? Bad fuel/air filter? Water in fuel?
it could be a bad fuel filter and fuel pump
I get about 13.8 mpg in my 2002 Escalade EXT. I do a mix of city and highway driving with mine. It's going to vary depending on the type of driving you do. These big nice luxury vehicles are much better for highway cruising than stop and start city driving.
You are not giving enough information to get a reasonable answer. It's like asking why it won't start. Any, and I mean any, detail would help. Are we talking about the engine cooling system? What are the symptoms that bring you to the conclusion it is overheating? Have you checked the coolant level? What year and size engine? Does it overheat only when stressing the engine, like climbing hills? Does it overheat only in traffic and okay on the highway? Does it overheat when the car is idling? Has the head gasket ever been replaced?
Two reasons could be that the motor was wired incorrectly or the load that the motor is driving is too heavy for the HP of the motor.
Yeah deffiantly
Lots of reasons, but mine was the fuel pump was bad. It would overheat after driving maybe 15 minutes, then I would let the car stop for an hour or two and it would start back up.
That will depend on how often you stop and start, and what speed you reach when running between stops. Generally, you'll find that city driving gives about 30% lower fuel efficiency than highway driving. It's interesting to note that the EPA numbers that most Americans use are estimates based on lab measurements, and the estimates for city are lowered by more than those for highway driving. This document http://www.epa.gov/otaq/cert/dearmfr/gasmel.pdf describes the process.
To drive from Vancouver to Anchorage, start by heading north on Highway 99 to cross the border into the United States, then take Interstate 5 (I-5) north through Washington. Continue on to Interstate 90 (I-90) east, then connect to the Alaska Highway (Highway 97) in British Columbia. Follow the Alaska Highway through Canada into Alaska, eventually reaching Anchorage. The journey covers approximately 2,200 miles and can take around 40 hours of driving time, not including stops.
They start panting and find some shade/water.