lazychina

I drove my accord in highway (50 mile/hr) and the a/c was on, but the water temp seems too high, the needle was on the 3/4 but not the midline, but after i drove for a while, the temp dropped back to normal. this repeated several times. is the thermostat problem or the water pump? thank you

danielm213

When you say the temp was 3/4 but not the middle do you mean the needle was on the left side of the midpoint? How many miles do you have? Is it a v6?

lazychina

yes, the needle is closed to the "H". my car is the 4 cylinder and has 101000 miles

HondaDen

Did you have your coolant flushed yet? If not, that's the first order of business. If the problem persists, replcace your thermastat. Is all your other routine maintanance Oil & filter) done on schedule and up to date?

lazychina

i will try

slomofo

iTrader: (1)

Does it do this with the A/C off? If not, then it could also be a fan problem or a dirty condenser.

danielm213

Just as HondaDen said, a coolant flush. I believe you should get your coolant flushed every 50K miles. Make sure your fan relays are working, coolant flush, check fans and condenser. good luck.

lazychina

the two fan are acutaly working. no matter my car is in local or highway, whenver i turn on the a/c my car gets overheat

lazychina

so i guess this should be caused by the thermostat

lazychina

i just flush the coolant and replace the thermostart, but the problem is stil there. when the tempe goes up i mean the needle at "H", the engine has a higher rpm, then i heard a "click" sound from the hood, and then the tempe dropes back to the normal, just wonder is it something wrong with ECT sensor or other senosr?

thank you

soon2bdropped

I had that happen to my 05 accord but threw a cel for ect sensor 2. one located on lower right of the radiator. i cleared the code and next day it came back on.. temperature was rising to the H. I had a customer car.. 06 acura tsx.. same engine.. never throw a code.. but using HDS(Honda scantool) found the ect sensor fluctating. while observing it saw that the temperature hit -40f a few time.. replaced the sensor. it fix the vehicle.. however make sure you dont have green corrosion on the connector. if so replace the sub connector, that will also cause a faulty reading.