Hi, sould my cars cooling fan start right away when i start the car because i think i have seen it spin when i have cold started it before. And now it does not. And the car has also a code that says cooling fan short to ground, can that be the problem that it does not start to spin? And the cooling temp goes also up and down.
The car is an Audi A3
Hello Cars. Your cooling fans should not start right away unless you live in a very warm climate like Arizona. The reason for this is that engines are designed to work at a set warm operating temperature for optimal efficiency. By using the thermostat and cooling fan temperature switch, a car can switch on its cooling system only after this set temperature is met. I looked up an A3 audi fan, it looks like it uses dual fans. It could be that only one is working. Drive it around your neighborhood for awhile until the temp gauge reads midway. Then pop the hood in the parking lot while its idling and check that both fans are running. You might get by with just one fan if you do highway miles but it's better to replace the electric motor or whatever you need to on the broken one to prevent an overheating issue.
And the car got also a new original thermostat a few weeks ago and after that the cooling temp started to go up and down don’t know why
Did you do the work yourself or did you take it in to the dealership? The only time I have personally seen that problem of a fluctuating temp gauge is when I have removed a thermostat entirely on an old honda while diagnosing some overheating issues. Depending on where you live that is not such a big deal. It used to be a thing with very older cars to remove the thermostat in the summer months and install it again in the winter. Thermostats open up slightly with the right temperature, by removing it entirely you increase the size of a hole that would have been maybe 1/10 of an inch to 2 inches diameter so there is alot more flow of coolant, hence rapid changes in the temp reading.
A guy that fix cars changed the thermostat while i was watching and i told him about that temp but he didn’t care.
I drove the car until the temp was up then checked but the fans weren’t spinning at all? And then i turned the A/C on and then they started to spin and when i turned A/C off fans stopped spinning? Is this normal?
Its abnormal in the sense that your cooling fan switch might be busted or disconnected (suspicious) . The one in my 96 civic has been busted for the longest time, I jimmied it by sticking a small piece of copper wire between the terminals to always short out. Normally the switch would heat up and close the circuit to an on position as the car gets up to operating temperature. Now my cooling fan turns out right after I start the car. It's not such a big deal living in southern california. My car gets up to temp pretty quickly. Your jimmy fix might be just running the A/C all the time, It looks like your a/c condenser and radiator are sandwiched on top of each other so turning the a/c on will turn the cooling fans on to help with the heat exchange.
Yeah some of these mobile mechanic guys are a bunch of hacks looking for more lay people to milk out on the regular. DIY what you can, find out where your cooling fan switch is and see that is connected properly. After that check for resistance levels coming off of the switch and voltage from the wire. You can do this with a 10usd multimeter from your local harbor freight or ebay.
But we’re so i find the cooling fan switch in my car, where did your cars switch we’re for example? So i can see if it’s there on my car
you gotta follow the coolant lines around, they'll be connected to the coolant directly to monitor the temperature. My switch is on my thermostat housing, it looks like yours is on the radiator from the pictures here.
On some cars if your AC is on it will make the fans kick in immediately. If you have a code that says the Fan is shorted and your temperature gauge is fluctuating after initial warmup then you should have it checked.
The car got also a new thermostat a few weeks ago and after that the cooling temp started to go up and down. And maybe something also to do whit the fan? That the temp goes up and down
Thermostat could be sticking intermittently
New does not mean known good, particularly with non-OEM aftermarket parts. If the new thermostat is not OEM, then replace it with an OEM part.
The other possibility is that the thermostat was installed incorrectly, either upside down or wrong side in.
The thermostat was a original one same as the old one
Cooling fan short to ground code is telling you that the computer is always measuring 0 resistance from the cooling fan switch/sensor so it doesn't know when to switch the fans on and off.
If nobody has been down there poking around with any wires then it's likely that replacing the Radiator Fan Thermal Switch (their name not mine) I call it a cooling fan sensor, will fix the problem.
Yours lives under the battery right at your lower radiator hose.
#5 in the diagram
