Engine Overheating?

[kev3636]

hi, i have an avensis 2001 estate which i brought with the engine management light on. i had it looked at and they replaced the coolant sensor and thermostat. now when it warms up the engine fans come on and stay on. is this normal? thanks for any help.

[igormus]

hi, i have an avensis 2001 estate which i brought with the engine management light on. i had it looked at and they replaced the coolant sensor and thermostat. now when it warms up the engine fans come on and stay on. is this normal? thanks for any help.

hello

how do you conside performance of the cooling pump impeller?

Besides - open cover from collant expantion tank and check with possible bulbs when the engine is idle run. in case the bulbes are available it means you have cyl cover gasket as burnt. Another problem is with an air presence in cooling chambers. ANother problem may be with vapours outgoing pipe/connection. so start to investigate the above first.

cheers/igor

[gazza1286]

This isn't normal. The fan should not come on until the needle on the dash reaches (or exceeds) the mid-point. If it comes on earlier and stays on there is a fault.

The fan is activated by the ECU and reacts to information sent by the coolant temperature sensor. The fan rarely stays on for more than 1 minute.

I would suggest that the replacement sensor is faulty. Either that or the incorrect part has been used. (that's what I think)The engine types changed in 2000 to VVTI. Check with Toyota to confirm that the part is correct as the location of the sensor also changed.

If the sensor wasn't plugged into the loom correctly, the fan would run permanently. I think also the engine management light would also flash.

BTW does the engine management light illuminate with all the other dash lights before the engine starts? If not, the bulb had blown and you may have another problem.

[kev3636]

thanks fpr reply. no engine light on dash,it is avvti, so im incline to agree about wrong part. i will take it back to garage, i will let you know what they say.

[kev3636]

garage say that coolant is going around system and all is normal. but fans are still on while driving around town. if left to idle fans do cut out then start up again after a few minutes.

[rfakins]

garage say that coolant is going around system and all is normal. but fans are still on while driving around town. if left to idle fans do cut out then start up again after a few minutes.

With your description, your car system is fine. The fan cuts in or out depending on the engine temperature. It stays on if you're using a/c but no need to worry since you said it cuts off on its own.

[kev3636]

yes the fan cuts off if you leave it to idle, but while driving when i stop at traffic lights the fan is always on. no a.con being used. so i think that the fans must be running all the time.

[igormus]

yes the fan cuts off if you leave it to idle, but while driving when i stop at traffic lights the fan is always on. no a.con being used. so i think that the fans must be running all the time.

hello again

note the themperature has an inertia ---> in other words when you drive around the town the engine is loaded and extracts more heat than when run as idle -- that is why the temp sensor gives a command to the fan to start up and take off heat from the coling system. Another thing -- A/C system has own heat exchanger that converts freon vapour to a liquid before throthle valve, so the only fan starting ccan convert valopu to a liquid resulting its starting even at idle run. It is understood the higher outside temp the more often fan starting. I do not see any problems then.

cheers/igor

[kev3636]

thanks for help igor. this is the only car ive driven that does this. does anyone elses do the same?