My Accord getting overheat.?

Question

My Honda Accord 2002 used to have normal temperature upto 35% (exact at all times), But these days from past week it fluctuates from 35% to 70%. If i drive fast its normal with or without ac. But if i drive slow in traffic it start rising upto 50% - 60% and if at that time i turn AC on or put in neutral and give extra race (throttle) then it come back to normal. Else it shoots upto 70% to 75% and then automatically start coming down to normal after 15-20sec of staying there.

Checked my battery: its fine as per the meter at the workshop and it starts in single self in morning. Radiator has coolant and its bottle also have enough coolant which i recently filled with original Honda coolant, No leakage of coolant from anywhere. Both fans of radiator working fine and cut off also auto. Both the radiator (In n out) hoses has roughly the same temperature, but sometime varies when i switch it off. Its one of the weird problem i have seen. Please advise me that what could be the problem

Answer 1

Your engine uses your radiator to do two things:

Get rid of heat from your engine

Keep your engine at a constant temperature, given the working parameters.

The thermostat is what tells other devices to let the radiator get rid or heat or retain it. It is the first device to check. I always pull, clean, test and reinstall if it passes.

If it had much gunk, then full radiator flush.

For a vehicle of this age, those are the high probability (over 50%) solutions.

to change thermostat:

First call Pep Boys to get a quote on replacing thermostat, flush and new fluid.

this can be an all day job the first time and quite messy.

you will need to have a new thermostat in your hand when you do this, and antifreeze.


I don't know your car specifically, but the thermostat is usually inside of a small hump, right where the radiator hose (top or bottom) goes to the engine block.


Drain radiator in a big bucket.

Once your figure out where thermostat is, usually you remove 2 or 3 bolts, to disassemble.

remember which way the old thermostat came out.

then a putty scrapper to remove the old gasket from both sides of the thermostat housing. (may have to take of a hose for convenience)

If curious, boil water in your kitchen with a candy thermometer and your thermostat to see if your thermostat opens correctly.

otherwise, just put in new thermostat, make sure old gasket scrapped off, install new gasket and maybe some gasket seal, bolt back together.

Inspect old radiator fluid; if dirty and has particulate, after installing new thermostat just put water in, get up to operating temp, and drain again, then replace with new antifreeze..


other wise if looking clean, put old fluid it back in.

top off radiator and test in driveway.

look for leaks, tighten things as needed.

I would advise asking how to do this on yahoo answers though.

Answer 2

Your Fan Relay needs to be replaced. When you say both fans work fine, did you test this based on letting the engine run "beyond" normal op. Temperature? As the temperature goes up, the fans should start up automatically to cool the engine.

I'm assuming that the fans works find with the A/C on because your A/C switch automatically turns on the Radiator Fans, and since you know the fans work

Unless you've already tested the relay switch, I'd start there.

You're email is not verified by Yahoo Answers so I can not respond to your email directly.

To answer your email question:
If you hear the relay tripping, and the fan turns on, does it turn off when the engine has cooled or does it turn off and the engine still continue to heat up.
1. If the fans turn off and the engine continues to heat then the relay switch is bad, it should not turn off.

2. If the fan relay doesn't turn on until your engine temperature is excessively hot (your 70-75%) then I'd say your temperature sensor is not sending a signal to the comptuer to trip the relay early enough. I would then test to be sure you don't have a bad temperature sensor that has become dirty and "insulated" with deposits and not tripping the relay early enough, thus you
see the wide range of temperature fluxation that you didn't see before.

Have your temperature sensor tested to be sure it's tripping the relay at the proper time/temperature?

Answer 3

I dont know about the fans, but I would check the thermostat and the temperature sensor for the coolant. If one or both goes, you can see some very odd problems.

Answer 4

might want to be various issues: a million. (obvious) low on coolant. and after I say coolant, i recommend antifreeze. this is not strong to run instantly water in any engine, fairly if it has an aluminum head etc. consistently ascertain you've a minimum of a 50/50 mix of water & antifreeze. instantly water causes corrosion contained in the water jackets of the engine. 2. thermostat staying open. low-cost restore,nicely worth a try, if it remains open, the water does'nt stay contained in the radiator lengthy sufficient to get cool. even as your taking position the line, there is extra air move than if you're in site visitors.

Answer 5

the first thing to check is if the fans are working with the a/c off, if they are then your thermostat may be stuck. when was the last time you changed the water pump?

Answer 6

your fan is have problems and the thermostat is not opening normally. change the t-stat and watch the fan. if it is not opeing at normal temps then the fan relay may need to be replaced. all of this is cheap so you can handle it.
good luck

Answer 7

Yes, sounds like the fan clutch/belt needs to be checked

Answer 8

thermostat needs to be replaced maybe?

Answer 9

thermostat!!!