Low coolant, inoperative water pump, head gasket failure, inoperative radiator fan, etc.
The usual reasons are one or more of the following 1. Radiator cap bad (system must be pressurized to cool properly) 2. Bad themostat 3. Lower radiator hose weak. (at speed, the hose can callopse restricting the water flow) 4. The viscus fan is bad (this is the fan that is driven by the fan belt. It has a slip clutch) 5. Old or Improper coolant mix in radiator (should be 50% water/50% coolant) 6. Radiator needs to be flushed or rodded 7. Timing too high. NOTE: do not remove the thermostat. it is there for a reason.
There could be several reasons, including the radiator being plugged up, the thermostat being stuck, and the water pump not working. Drain the coolant, and check for signs of rust or corrosion in the coolant. Remove the thermostat, replace the coolant, and run the engine. If the problem persists, take it to garage. Troubleshooting by changing out parts will be too expensive. check and change thermostat if done this problem is either head gasket or cracked head
The most common problem with 1999 and up Jeeps over heating is the cooling fan relay. On your 2003 Jeep, if it has an A/C, check to see if the A/C clutch remains engaged when you turn it on. Both the cooling fan and the A/C clutch runs off the same relay circuit. The cooling fan relay is located below the passenger side head light assembly, you'll need to remove the fachia to access it. Low coolant Cooling fan not working Defective thermostat Plugged or restricted radiator Bad radiator cap System airbound Hoses collapsing under pressure Water pump not circulating coolant
Check the operating mechanism
The obvious answer would be that there would be a leak somewhere...
A bad water pump or thermostat can cause an engine to overheat. A plugged (clogged) radiator or heater core may also cause an engine to overheat.
a. blown headgasket. b. defective thermostat. c. defective radiator. d. no oil, no coolant.
Bad thermostat, water pump not circulating, low coolant level, head gasket leak.
Causes include low coolant, inoperative radiator fan, plugged radiator, stuck thermostat, water pump malfunction, head gasket failure.
A 1991 Subaru Impreza might overheat because of a leaking cooling system or because of a damaged thermostat. You might also have a damaged or leaking radiator or a cooling fan that is not working.
There are many ways that it can overheat. Coolant loss, blown head gasket, stuck thermostat, clogged radiator ar only a few. You would have to consult a mechanic to know for sure why it is overheating.
It could be a number of things, a clogged radiator,bad thermostat,low coolant, hoses leaking coolant, radiator fan not working,or a leaking head gasket. Hope this helps you.
You may have the thermostat in backwards. The spring side of the thermostat faces into the engine.
BAd radiator cap, low coolant or (leaking), Bad thermostat, cooling fans not turning on.
Bad Head gasket? Low coolant? Clogged radiator? Bad thermostat? System airbound? Defective radiator cap? Collapsing radiator hoses? Cooling fan not working? Water pump not circulating coolant?
Thermostat is stuck closed.
#1-clugged radiator #2-bad water pump #3-air in system #4-bad temp sender switch