1997 Toyota Avalon Fan for cooling engine wont work

COOLATTA

MEMBER
1997 TOYOTA AVALON
6 CYL
2WD
AUTOMATIC
136,000 MILES

I have 2 fans for the engine, they dont come on to cool the engine, but if I turn on my a/c they will come on.
The car is overheating and the gage is not showing that the car is hot and it is leaking anti-freeze from the top seal of the radiator.
I know I will have to now replace the radiator but what is causing the fans not to turn on to cool the engine but will work when turning on the A/C?
What is wrong?
And I am curious to know if all diagnostic machines are the same at different garages. I have Toyota who will put it on diagnostic and check it for 110.00, and a mom/pop shop who said they would charge me 15.00 to put it on diagnostic. Is one better then the other?

1 Reply

BLUELIGHTNIN6

MECHANIC
16,542 POSTS

Issue most likely is a faulty engine coolant temperature (ECT) sensor. This is the sensor used for the temp. Gauge as well as what helps the computer know when to turn the cooling fans on. When a/c is switched on a different sensor is used to automatically kick on the fans. As for diagnostic machines, there are many different types. Obviously Toyota is going to have a top of the line machine while the smaller shop you speak of COULD have the same, although most likely they have a much cheaper kind. In any event, I would not take it to either if this is the only problem you have, as the ECT sensor is the fault here. If the engine light is on you could actually take vehicle to local auto part store and ask them to scan codes for you, most do it for free.