Coolant Temperature AMF

Hello,

"For quite some time, the dual temperature sensor in my car has occasionally been giving the instrument cluster incorrect readings. It never really bothered me because it was only wrong on the instrument cluster. Unfortunately, this effect has been getting worse, and I've now replaced the sensor. During my drives, I noticed that the engine temperature is also consistently being held at 80°C. The thermostat opening point is actually higher than that, so it should be getting warmer. Even longer trips at full throttle don't make a difference; it's actually being regulated to this temperature, and it would normally get warmer."

Can I now assume that the thermostat is defective, or is it simply a matter of an unfavorable arrangement of the thermostat and the temperature sensor?
What is the direction of the river's flow?

Engine (hot) -> Thermostat -> Radiator -> Temperature sensor -> Engine (cold)

Thank you!

Hi,
Typically, there are two cooling circuits: a smaller one and a larger one. In addition, there is the heating circuit, which may have a branch leading to the oil cooler.
The thermostat mixes hot water (from the cylinder head) and cold water (from the radiator) and the water pump draws this mixture in and pumps it into the engine block. From there, it flows back to the cylinder head, and then to the heating circuit, and also to both cooling circuits.
I suspect that the AMF (Automatic Manual Function) for the EDC (Electronic Diesel Control) also uses a separate temperature sensor for the engine temperature, which is located on the side of the cylinder head flange.
How does the engine temperature reading provided by VCDS compare to the reading displayed on the instrument cluster (KI)?
hg
Herbert.

Hello Herbert,

Quote:

How does the engine temperature reading provided by VCDS compare to the reading displayed on the instrument cluster (IC)?

They are identical except for a difference of 1°C.


Dirk.

Hello!
Already read: /viewtopic.php?t=23345&highlight=thermostat?
haithamina

Hello Dirk,
The thermostat seems to be activating a bit too early. Normally, during the colder months, you would expect a stable temperature at the lower end of the operating range (around 87° for a 1Z model, but it might be different for you).
As long as the engine warms up quickly enough, I wouldn't do anything and would postpone replacing the thermostat until a more convenient time. Mine also opens a bit early.
Sure, here is the translation of the text from German to English:

"vg"

This is a common abbreviation for "very good" in German. It is often used in online forums and chat rooms.
Herbert.

Hello!

Ash on my head, I hadn't read the thread. It actually describes my problem exactly .

Feel free to delete this thread if you want. Thank you for the heads-up!

I decided to replace the thermostat today, even though the weather was relatively warm. It cost 22 euros. I'll check tomorrow morning to see how high the temperature goes now. Both thermostats have "87°C" printed on them as the opening temperature.
I might try "cooking" some old [items/things] in a pot in the next few days.

I will submit the final report again tomorrow.
Thank you to everyone!!

brezelmann01 wrote:

I'll check again tomorrow morning to see how high the temperature has risen. Both have 87°C printed on them as the opening temperature.

You're welcome!
Okay, I'm guessing it's around, approximately, close to 87°C at partial load...
haithamina

Okay, here's the conclusion:

The temperature stabilizes around 90°C during normal driving, which is fine.

Update 01/23/11: Today, I tested the old thermostat in the rice bag water.
Just like in a car, the thermostat starts to open at 76°...


Dirk.