Hi there.. recently my car was over heating for the first time when driving on a hot humid day on the highway with the AC on and going around 70-75..
I changed the thermostat and add new coolant... everything seem fine... UNTIL today

today i went to the beach and i drove on the parkway for about 30 minutes.... at one time.. i rep the car to 4to 6K RPM cause i need to pass this car..... then in 5 minutes.. my temp went close to red line... so i slow down and turn off the AC..... drop to an exit and i stop the car.. pop the hood up and look to see what happen.... The coolant in the resvoir is almost to the top... both fans are runnning... i touch both of the radiator hoses and both are hot........

turn off the car let it sit for 20 minutes.. start it up... the temp went down to normal... with AC off and driving at 40-50 MPH.

Got to the beach and enjoy and entire day there...
When going home.. I didn't turn on the AC... but going around 50-65MP and the car seem fine....... then after i drop off some people.. I drove home .....

I tested to see how the car reacted.....
So i accelerated slowly to 65-70 range and drove home with AC on for around 45 minutes... the car seem find... the temp is at normal reading...
Then when i am almost near home.. I did a test....... I rep the car to 5K RPM and speed to 80MPH ....... then 3 minutes later.. the temp boost up again to high.....

when i get home park the car.....(car still running) pop the hood... both fans are on.........coolant is at max... not over like before...
turn off engine... turn engine on again....... temp went down to half way.....

I had changed the oil last week.
clean my oil filter.
new coolant was added 3 weeks ago.
new thermostat was installed.
there is no leak.
new AC coolant was added

Doesn't anybody know what is going on?????

and when i rep the car to 6 RPM on parkway.. my friends say my car has alot of black smoke came out of it.
also when temp get hot..... the ac tending to shut off cool air.. dont know why.

 

Did you bleed the system after you changed the thermostat etc? Are you using a honda OEM thermostat or aftermarket? Are you burning/using any oil?

 

i dont think they bleed the system... they just put more coolant after they installed the thermostat.
thermosstat is OEM.

dont think i m burning oil.. just checked in the morning... oil is below second dot on the stick.

i drove earlier and the car seem fine with AC on.........

 

make sure that the radiator cap is ok... also make sur that both fans are working properly ,,and lastly make sure that there is good air flow through a/c condensor.. and radiator ..

if all is ok,, have a shop do a leakage test

 

but why does it only get high temperature when i hit the car at hight rpm?????

other then that it is ok

 

Higher RPM's creates more friction, more friction creates more heat, more heat leads to overheating if your car isn't cooling properly... Find out if they bled the system, if not I'd suggest doing that, air bubles in your coolant lines can cause some strange things...Also, check the items that deserthonda mentioned.

 

ok.. thank you..
will check it out tomorrow and will keep it update.

 

Another suggestion:

This problem could be the result of combustion entering the cooling system.

You mention it is happeningfollowingsudden acceleration of the engine. Combustion gas can enter the cooling via a defective head gasket.

One test you may be able to perform yourself is to remove the radiator cap, warm the engine to operating temp, and when the coolant begins to circulate through the radiator, gun the engine in short bursts and watch ,or have someone watch, for bubbles in the top of the radiator. If there are - it could be exhaust gas bubbles leaking into the system. If this is the case - these gas bubbles would increase the temp and pressure in the system, when it is closed and pressurized, resulting in the condition you are experiencing.



Good luck