Technical Temperature needle moves up and down with the engine started but not moving.

[MKUser]

Hi, I 'm noticing the temperatur needle starts to "dance", going up and down and raising up after a while if you are stopped but with the engine on.
When you're on the road, the temperature is on the middle without any problem.
The thing is when you stop for a while.
I don't hear the cooling fans going even the temperature goes up.
I've checked the fans fuses and they are ok.
The water pump has been changed a few weeks ago.
I don't know if it's a temperature sensor or what.
Anyone has an idea of the problem??

 

[the green vanper]

Hello,

It's normal the engine is cooled better when driving. It is how the system has been engineered. It is cooled by the air flow. When the car is stationary, the fan installed on the radiator has to do the job.

However I'd say that the temperature should get higher constantly from ambient to the point that the fan kicks in. Normally it's around 80 - 90 - 100 degrees, depending on the model. Then it should drop.

Is the movement of the needle smooth? or sudden? The 'dancing' happens at which temperatures? Have you got an obd reader and could check with torque or car scanner? Those are free apps. At least on an android phone.

What's the model and year of the Ducato? and the engine?

 

[MKUser]

Hello,

It's normal the engine is cooled better when driving. It is how the system has been engineered. It is cooled by the air flow. When the car is stationary, the fan installed on the radiator has to do the job.

However I'd say that the temperature should get higher constantly from ambient to the point that the fan kicks in. Normally it's around 80 - 90 - 100 degrees, depending on the model. Then it should drop.

Is the movement of the needle smooth? or sudden? The 'dancing' happens at which temperatures? Have you got an obd reader and could check with torque or car scanner? Those are free apps. At least on an android phone.

What's the model and year of the Ducato? and the engine?

Hey, thanks for the answer.
When running, the needle stays in the middle ( 90 I suppose) without any problem as always.
The thing is if you stop with the engine on , without moving.
After 3 or four minutes, the needle starts to oscillate each time rising up,
arriving near the hot position.
The cool fans don't start in any moment .
I'm afraid of a serious problem if I'm envolved in a traffic jam, having to stay in ralenti a lot of time.
The engine is a 8140.43S Sofim for a Ducato 2.8 jtd ( 2003).
I don't have the Obd at the moment but may try to buy one.
I've readed this engine has two sensors , one for the cool fans and other for temperature gauge.
I've thought maybe the problem is in this last sensor.
What do you think?

 

[Communicator]

Hey, thanks for the answer.
When running, the needle stays in the middle ( 90 I suppose) without any problem as always.
The thing is if you stop with the engine on , without moving.
After 3 or four minutes, the needle starts to oscillate each time rising up,
arriving near the hot position.
The cool fans don't start in any moment .
I'm afraid of a serious problem if I'm envolved in a traffic jam, having to stay in ralenti a lot of time.
The engine is a 8140.43S Sofim for a Ducato 2.8 jtd ( 2003).
I don't have the Obd at the moment but may try to buy one.
I've readed this engine has two sensors , one for the cool fans and other for temperature gauge.
I've thought maybe the problem is in this last sensor.
What do you think?

As stated the 2.8jtd has two temperature sensors. The sensor for the gauge also has a thermostatic switch for the high temperature warning light. Both sensor and switch use a common earth return via the sensor body, which is poorly shown on eLearn wiring daigram.

It is worth noting that all four analogue indications on the x244 model use electronically driven stepping motors which can stick.
I had a problem on my 2,8jtd with initial temperature indication being normal immediately when switching ignition engine, but when engine was still cold.

After preparing to change the sensor, I discovered that problem was due to a bad contact at the sensor connector. Problem was fixed after reseating the connector, but contact cleaner was applied as a precaution.

Access to the sensor is either by removing air filter and inlet hoses, or by removing intercooler hoses. The gauge sensor is the larger of the two with connector blades at right ange in roughly circular connector. M16 x 1.5 and 22mm over hexagon (spanner size).

 

[MKUser]

As stated the 2.8jtd has two temperature sensors. The sensor for the gauge also has a thermostatic switch for the high temperature warning light. Both sensor and switch use a common earth return via the sensor body, which is poorly shown on eLearn wiring daigram.

It is worth noting that all four analogue indications on the x244 model use electronically driven stepping motors which can stick.
I had a problem on my 2,8jtd with initial temperature indication being normal immediately when switching ignition engine, but when engine was still cold.

After preparing to change the sensor, I discovered that problem was due to a bad contact at the sensor connector. Problem was fixed after reseating the connector, but contact cleaner was applied as a precaution.

Access to the sensor is either by removing air filter and inlet hoses, or by removing intercooler hoses. The gauge sensor is the larger of the two with connector blades at right ange in roughly circular connector. M16 x 1.5 and 22mm over hexagon (spanner size).

Thanks for your comment...I'll check the sensors.
Do you have any picture to find these easier??

 

[Communicator]

Thanks for your comment...I'll check the sensors.
Do you have any picture to find these easier??

See post #12 in this thread. Or use the search function to look for more.