207 heat problem

First of all hello friends I have a problem like this I would be very happy if you help me no matter what I do I can't reduce the temperature of my car. The temperature of the car is always between 90-95 of course if the line above 90 is 95 I go on a road for 30-40 km with the car. The temperature of the car is normal at 30 km/h but after that it goes up to the highest levels. I immediately pull the car over and open the hood. I turn on the 2nd stage fan and it slowly reduces the temperature. They said that the head gasket was burnt because of this problem in my car before. At this time the entire upper set of gaskets were changed. Cylinder head gasket, intake, exhaust valves, valve rubbers, thermostat, timing set, water pump temperature sensor (Delphi) and radiator hoses. Note: The temperature drops when the car is going downhill in idle. The fans are also working stable. I had it calibrated. It works manually with the program. I can't figure out what needs to be changed. There is nothing left that hasn't changed in the car but I can't solve the temperature problem. I would be very happy if you can help me. Thank you in advance.

By the way, my car is a 207 1.4 engine, 75 hp, 8 valve gasoline engine, 2007 model.

Hello, your vehicle's fan turns on at 97°C and turns off when the temperature drops to 93°C. This means that the operating temperature is between these degrees for average city use. A healthy cooling system should reduce the temperature from 97°C to 93°C within a maximum of 10-15 seconds when the fan is activated. So, why doesn't the temperature drop? Even if the thermostat is new, it's a mechanical part. Therefore, it can sometimes be faulty in brand new thermostats. Sometimes it doesn't open, sometimes it stays open, and so on. Another reason is that in cooling systems where the water radiator is forced to operate with drinking or tap water, rust, along with small iron dust or particles, can build up over time, impairing water flow through the thin channels in the radiator. The water cycle in the system slows down, leading to slower cooling. This problem can also occur in the heater radiator. The water in the block heats up in the heater radiator and the block before the thermostat opens. When the thermostat opens, the hot water here flows to the radiator, and the cooled water from the radiator flows to the radiator. Therefore, a blockage here blocks the water flow. I could go on and on; there are many more, but all of them are the same. It remains a guess, therefore it is a malfunction that needs to be investigated and everything needs to be reviewed, but it is definitely not an unsolvable problem. It can be solved in a short time.

Thank you for your comment, sir. First of all, the heater core of the car has been changed. Thinking that the problem might be the thermostat, I used the car after emptying the thermostat. Nothing changed. I took it to another mechanic yesterday. He said that my catalyst might be full. The exhaust manifold of the car is at the front, right in front of the fan, and there is already a catalyst under it. He said that if it is clogged, it can also cause overheating. I will have him check it and also remove the radiator and have it checked. There is nothing left because I don't think there is a blockage in the hoses because when I drive the car idle on the highway, the car revs up and reduces the temperature. After having the catalyst checked, I will write here again. When the OBD is connected, it gives a catalyst fault and the exhaust sound is not normal. It also makes a crackling noise when I tighten it. I think the problem is in the catalyst, but we will see.

If it's displaying such a fault code, that's the area you should definitely look for. A clogged cathode can significantly reduce vehicle performance and cause overheating. Your problem could also be a faulty Lambda (oxygen) sensor. A faulty Lambda sensor can't regulate the air-fuel mixture correctly, either running lean or rich, which can cause excessive heat buildup. Air-fuel mixture errors are the primary cause of a clogged cathode. If the catalytic converter is severely clogged, overheating will skyrocket. This is clearly evident in the car's traction. Hopefully, that's the problem.

I hope it's that one, sir. As you said, the oxygen sensor is also giving a fault. The vehicle also has a catalytic converter fault. I will also have it checked and see if we can solve the problem with the catalytic converter. The only thing left that I haven't had checked is the catalytic converter and the radiator.

Has the problem been resolved, Mr. Muhammet? I'm having similar problems.

Sir, have the car's radiator checked directly. I completely drained the catalytic converter, but nothing changed. I changed the radiator. Now the warm-up time is slower, and it is now more difficult to reach the 90 mark. It used to reach that mark immediately. What is your problem? There is no guarantee that every heat will come out of the radiator. Also, is your car diesel or gasoline?

With the permission of the author, I have a small question. The temperature indicator on my 207 diesel is always fixed just above the 90-degree mark. Is this normal, or should it stay around 85? Does this damage the engine? I found an example photo below. https://i0.wp.com/hizsabitleme.com/wp-content/uploads/2022/12/IMG_20221210_181920_060.webp antipollution2023-12-11 19:37:33