Whats wrong with the car cooling system?

You don't identify your car for us.

It's actually best if you tell us.

When driving, the movement of the car through the air, takes the heat from the radiator.

But when moving slowly or not moving or parking, the fan must blow air through the radiator.

Years ago, the fan was driven by a belt and pulley on the water pump, but in recent times, the fan or fans are electrically operated.

So open your hood with your engine running, after you have driven and the engine is warm, and look to see if your fan or fans are running. If not, shut the engine off. You have to find out why. Could be a bad fan motor, or could be an electrical problem, like the wiring, or a connector or a fan relay or a fuse. If the fan or fans are not running, best to find somebody who understands electricity to find the problem.

Check whether your city library or local college library has an online subscription to Alldata. You look up your exact car and can get a complete electrical wiring diagram for the car. So you can look at the fan circuit and see what is involved.

Or you can get a factory service manual, sometimes available in large libraries.

Or you can maybe get a new factory service manual from www.helminc.com for your car. They have many, but not all brands. Some brand manufacturers sell the service manuals from their parts departments.

As the others are suggesting, a radiator fan is the first place to look.

Explanation -

When you are driving along the wind is blowing through the radiator, and that keeps the engine cool enough. The fan isn't even running. When you stop, but the engine is still running, a fan should start up to keep the air going through the radiator. If it doesn't, the engine overheats.

Now it could be the fan motor, a relay, broken wire, or bad sensor. But it's probably something to do with that fan.

ES9J4 Engine what a BEAST. This is possible to check using a 4 gas analyser any Mot testing station will have this with the engine running and the rad cap removed hold the exhaust pipe just in the neck off the header tank then watch Hydro Carbons if they rise dramatically then you know that the head gaskets have failed . Please take a Reading before you put the pipe into the header tank to get a base Reading .If after a few minutes of running when warm no rise then we can say your head gaskets are fine .

I agree with fan diagnosis, but depending on model, it is probably an electric fan. Could be the fan motor or switch, etc. Don't let it overheat. That will cause much more serious problems. Get it fixed quickly

Check the fan clutch. Sounds like the fan isn't engaging.

sounds like the cooling fans are not working, or you have air trapped in the radiator.

sounds like it might be a fan prblem