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View Full Version : My 1990 honda accord is running hot too quick what's going on


Damon1991
Jan 20, 2014, 10:57 AM
After running for a few minutes it over heat quickly what is happening

odinn7
Jan 20, 2014, 12:11 PM
Fans
Thermostat
Low coolant
Bad water pump
Bad head gasket

TxGreaseMonkey
Jan 20, 2014, 12:29 PM
Common causes of overheating:

1. Insufficient coolant and/or air in the system. When the system is cool,check the radiator and overflow tank coolant level. If the level is low, startlooking for leaks. Check for deteriorated or damaged radiator and heater hoses;e.g., cracks, pin holes, and clamps that leak under pressure. Also, look forbulges and collapsed hoses. Attach a cooling system pressure tester to theradiator, if necessary, to help locate leaks. Pressurize the system to 16 psi.Learn how to properly purge your cooling system of air--this can be crucial insome vehicles. On many Hondas, for instance, fill the radiator with coolant,until it comes out of the opened bleeder bolt. It's important to follow the exact procedure for draining and fillingthe cooling system in the Owner's Manual--they do vary and it's veryimportant. Failure to do so can resultin a warped head, blown head gasket, and the engine seriously overheating.

2. Air flow problems--leaves, bugs, dirt, feathers, or plastic bags blockingthe flow of air through the radiator. Gently clean the radiator with a gardenhose.

3. Radiator fan not operating properly--check fuses; Engine Coolant Temperature(ECT) Switch, not the ECT Sensor; and radiator fan relay. The cooling fan notoperating properly is one of the most common reasons engines overheat. If the coolant is low and/or there's air in the system, the ECT Switch may notturn the radiator fan on.

4. Radiator shroud does not seal tightly enough for the fan to draw air throughthe radiator. This can cause the engine to overheat, while the vehicle isstopped.

5. Faulty radiator cap--doesn't maintain proper pressure or one or more valvesare bad. Test cap relief pressure with a radiator cap tester (KD 3700 or Stant12270). On non-expansion tank systems, which are most systems besides Ford's,there are two valves inside the cap that can fail. One allows hot coolant toflow into the overflow tank, the other allows coolant to flow from the overflowtank to the radiator, as the engine cools. If the coolant can't flow back intothe engine, there won't be enough coolant and the engine can overheat. It'sbest to use a high quality, preferably OEM, cap.

6. Faulty thermostat--sticking closed. Improperly installed thermostats are oneof the leading causes of Hondas overheating.

7. Radiator core blocked--mineral build-up (phosphate scale) and corrosion arethe most common causes.

8. Inoperative water pump--pinch the top radiator hose closed with your hand,while the engine is idling, then release it. You should be able to feel a surgeof coolant, if the pump is working properly. Change the water pump every timeyou change the timing belt.

9. Improper grade of engine oil--higher viscosity oil generates more internalfriction and heat. Synthetic engine oils have higher coefficients of heat thanconventional oils, which allows bearings and engines to run cooler--use them.