Keeps overheating. Heat works great, replaced thermostat, fan doesn't kick on so I replaced the relay, fan still doesn't come one. Coolant light stays on but plenty of anti freeze. I'm at a loss...

Water pump bad

Sounds like this may be a faulty fan motor, the low speed in these fan assemblys go bad, but the hi speed works when the a/c is turned on. I would check for the cooling fan relay first... you can usually switch this relay with another relay of the same and see if that makes the fan kick on, if it doesn't then i would go with replacing the electric cooling fan motor. Hope this helps

as for noise will have to inspect under hood,could be fan or belt or pulley ,water pump .these are some things it could...My suggestion for overheating is replace thermostat. If your car has electric cooling fan then it may not be working..turn defrost on and if fan kicks on then fan motor is good..Now this does not mean that fan is working properly because fan is controlled by heat sensor switch that kicks fan on when motor reaches heat range......Things i would have checked....hope this information helps and good luck and Please rate my post...

FIRST OF ALL I WOULD REPLACE THERMOSTAT AND RADIATOR PRESSURE CAP THEN CHECK SEE IF COOLING FAN RUNNING.WHILE CAR OVERHEATING. IF NOT CHECK COOLING FAN FUSE AND RELAY.IF ALL IS GOOD THE ENGINE COOLANT TEMPERATURE SENSOR COULD BE FAULTY.HOT WIRE SEE COOLANT FAN WORKS IF NOT, COOLING FAN MOTOR BAD NEED REPLACING.IF COOLING FAN MOTOR WORKING PROBLEM COULD BE IN FAN MOTOR WIRING OR PCM FAILED.

You missed the cheapest and most likely part of all. Change your thermostat. It may be sticking. Incidentally, coolant is suppose to not only back up into your reservoir on occasion, it is suppose to take from it as well. This is normal.

Unless you are using old antifreeze with enough globs of crud in it to constrict your thermostat and prevent good coolant movement, your overheating is more likely caused by a problem with your electric fan, rather than a problem with your thermostat. The fans in front of your radiator and A/C heat exchanger don't do anything when your car is moving faster than, say, 20 or 25 miles per hour. If you only drove on the highway, you wouldn't even need a fan. However, they're really needed when you're sitting at a stoplight or driving at low speed.

Your fan system has a few possible trouble spots. I believe that your Accord has an electric, not a belt-driven main fan. And, those electric fans do go bad. This is not uncommon; fans are stuck out in the elements, and they can rust up, a blade can crack, or the contacts could corrode. You can test this by jumping 12v of power to the fan terminals to see if it spins up--and stays spinning for at least 30 seconds or so. A fan may work briefly and then cut out if its bearings are shot--as they overheat and expand, they'll grind the fan to a halt. If your fan seems to be working fine, double-check that the wiring connectors are nice and shiny so that they're making a good connection.

Second, and equally possible, your fan relay may have gone bad. There's a coolant temperature sensor that is designed to send a signal to the fan relay if the coolant gets too hot. That relay has a mechanical element in it that also can go bad--it may be receiving the signal to do something, but the relay isn't closing properly to kick off the fan.

Third, the coolant sensor sending a signal to the fan relay may also have gone bad. This is normally a separate sensor from the one sending a signal to the temperature gauge in your dashboard.

Driving entirely without a thermostat will greatly lower the coolant temperature in your car and will give you a temporary fix for this problem while you troubleshoot your fan system. However, because the coolant will never fully heat up, you may experience a decrease in fuel economy and your tailpipe emissions may go up. And, of course, you won't get very much heat from your climate control system. Driving without a thermostat is a short-term fix, not the solution to your problem.

You may either have a bad thermostat or a bad fan relay. If the fan is not turning on at all then the relay is bad. If there is not any heat coming through the heater then your heater core is plugged. That would also cause an overheating problem as well. To rule out a bad relay check to see if you are getting 12 volts at the fan connection. If not change relay.

Over heating can be caused by a faulty thermostat and or weak water pump and dirty radiator and old antifreeze or the radiator fan now working when at idle but should not over heat when driving. Service the cooling system if it has never been serviced before. Replace the thermostat, buy some radiator flush to clean out the radiator and heater core. Just follow the instruction and replace the antifreeze and make sure it's a 50/50 mix water/antifreeze. If you not sure how to mix it 50/50 you can buy them 50/50 premixed. Water boils at 100'C so you need antifreeze mixed with it but antifreeze does not have the same heat transfer as water so you cannot run 100% antifreeze cause it does not transfer heat fast enough and you over heat. Good luck and hope this helps. Keep me posted, Be glad to help, once you service the cooling system and your still over heating, then we look at the water pump.

many things could cause the overheating. broken water pump impeller, stuck thermostat, clogged radiator, inoperative cooling fan on the radiator.

i would first check to see if the cooling fan on the radiator is working. when it reaches operating temp (or surpasses it in your case), see if the fan attached to the radiator kicks on. if its not on, then either the fan has failed or the temp relay to kick on the fan has failed. also, make sure the connector is plugged in.

after its at operating temp, turn off the car and feel the radiator. if you feel cool spots, then it is clogged and needs replacing.

wile under the hood and car is off, feel the upper & lower radiator hoses. if one is hot and the other is cool, then either the water pump (actually the impeller on it) has failed and is not circulating coolant through the radiator. a common problem in this model.

but it could also be the thermostat. if failed, it would not allow coolant to flow & circulate.

hopefull one of the above items is the problem. good luck.

the first thing to check is to have the engine running. as soon as it reaches operating temp the upper radiator hose should get hot. if it doesn't then it's the thermostat. if it does then i believe your water pump is probably not circulating like it should and it should be replaced. however before replacing the wter pump make sure that the wire to sending unit is tight and not giving you a false reading. if your model has electric fans make sure the fans are running when the engine is hot. if they are not running check the relay in the fuse box for the fans with the engine running switch out the fan relay with the a/c clutch relay. ifthe fans kick on replay the relay with a new one. if they don't click on the it's either a bad wire or the temp sensor probe is bad. hope this answers your question. please rate this solution...thanks.