Coolant Temperature: Engine vs. Radiator Outlet

Hello friends,

I have a question about my Octavia (BKD, 2.0 TDI).


What could it indicate if the temperature at the cooler outlet is too low?
For example, the measured value for coolant temperature at the engine outlet is 83 degrees Celsius, while the value for coolant temperature at the radiator outlet is between 20 and 40 degrees Celsius.

According to the label file, both items state "minimum temperature of 75°."
What could be the reason for the low value? What is the relationship between coolant temperature, engine output, and radiator outlet temperature?

Regards,

Serdar.

Well...

What does a cooler do? What is its function, especially at an outside temperature of -20°C?

it cools - and it does so very well!

The liquid coming out of the chiller will, of course, be very cold. The label file is not omniscient and is certainly not valid for every operating condition.

Quote:

002,1,Motor speed,(G28),Target value (idle): 790...810 RPM\nTarget value (full load): 2800...3200 RPM

"When I start my bike cold, the engine revs up to 1000 RPM. At 220 km/h, it's over 4000 RPM... is something wrong with it?"
NO, the label file alone cannot describe all possibilities.

Take a look at the other texts in block 062... then you'll understand what I mean.

Greetings.
Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Thank you, Martin.
However, the stated temperature is misleading. It never actually reaches at least 75°C under any normal conditions, unless the coolant is boiling.

It's just difficult for Uwe Ross to find a middle ground that is understandable to everyone, one that allows for short tooltips while still providing enough information.

A tooltip that is as large as your monitor is also not very useful anymore .

greetings
Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Hello,
"I have now read the coolant temperature from the instrument cluster's control unit for two days. On January 1st, this happened after several minutes with the ignition on, at an outside temperature of -3°C. Therefore, I didn't think much of the displayed water temperature of 5°C, and thought, 'Ah, the cooling system is working...'"
Yesterday, with a temperature of -10°C and the PC starting up quickly, the water temperature rose to 5°C. I have a STG motor, model MWB 7, but I haven't checked anything yet... My apologies.
Are the same temperature values expected there? In other words, is the water temperature sensor defective?
The repair shop suggested that I remove the sensor because there are various types available for the ABS system as well, and to let them know the color or part number.
"Could someone tell me the exact location of this part, or know its correct name and part number, even if it's not for disassembly, for a VW Golf (AVB) manufactured in 2003 with an engine power of 74 kW?"
You're welcome, haithamina.
P.S. The preheating process works; for example, today, with a frosty temperature of -13°C, it preheated sufficiently and started up well.
/viewtopic.php?t=20265

Hello,

The sensors tend to break relatively quickly; the MWB 7 is highly recommended.

Quote:

Are the same temperature values expected there?

Yes.

Best regards, Rainer.

Thank you, Rainer.
I had feared that. The sensor is located at the top of the cylinder head, in front of the connection for the heating system's heat exchanger, right? Only the gasoline engine version is documented in the Etzold manual.
Do I need any special tools for assembly and disassembly? Does the coolant remain in the system when removing the sensor? So, can I just take it to a regular workshop, have them quickly remove the sensor, show it to them, put it back in, have them order a replacement, and then replace it later?
haithamina

Good evening.

/viewtopic.php?p=142633#142633

The temperature values from January 10, 2009, were read from the combination instrument, not directly from the engine control unit (ECU) via diagnostic trouble code (DTC) 7. After that, it appears that the sensor (G2?) for coolant temperature is defective.

On January 11, 2009, data was read from the following control units: STG Motor 3-7-10 and STG KombiInstrument 1-2-3.
"The STG combination instrument reported an error for the G2 sensor, including 'plus...sporadic...etc.' The G2 sensor indicated 5°C, although the actual temperature was -4°C. The error could be cleared, and it did not reappear on the first subsequent trip."
All temperature values for the STG motor were correct and within range (-2.7°C to -5.4°C).

Does that mean the Engine Control Unit (ECU) receives its coolant temperature values from sensor G2 at the cylinder head, and the Engine Management System (EMS) receives them from sensor G62?
Is it connected to the thermostat instead of the central unit?
Is the sensor at the engine control unit (STG combination instrument) broken, or does it always display a temperature of 5°C when the temperature is below or equal to 5°C?
Apparently, the preheating function is being controlled by the G62 module, because the preheating itself seems to be working correctly.
Is it advisable to replace the power supply for the combined instrument (STG) even if there are no apparent issues?
haithamina

Hello,

The G62 and the G2 are the same component (they used to be two separate components).

The coolant temperature sensor has 4 pins.

One part is called G2 (-> display), and the other is called G62 (engine control unit).

In my opinion, extensive testing of the G62/G2 models is not worthwhile. These devices frequently break down and are relatively inexpensive.

"So, spend 25 euros and invest 5 minutes of work, and it's done."

Quote:

So, can I drive to a free repair shop, quickly remove the sensor, show it to them, put it back in, have them order a replacement, and then replace it later?

Why be so complicated?

Go to the auto parts store. They probably have the part in stock, so you can take it with you right away and install it later at your leisure.

@ schraubischlumpf
Ahem!
You haven't read it correctly and didn't look at the upload, which contains two tables.
In one engine control unit (ECU - part number MWB 7), I'm getting the correct temperature reading, but in another (combination instrument - part number MWB 3), I'm getting an incorrect reading that is strangely always "+5°C" higher than it should be when the engine is cold.
The preheating function is working correctly, which suggests that the glow plugs are connected to the STG engine, model MWB 7. However, preheating starts already at 5°C...
Is there a coolant temperature sensor for both control units (STGs)? And if so, how does the error occur in the combined instrument cluster (STG KombiInstr.), module code 3 (MWB 3)?
haithamina

Enjoy your meal.

I haven't actually looked at the tables .

The question is:

-Does the coolant temperature sensor measure A specific temperature and transmit it to the combination control unit and engine management system, or...?

-he determines the coolant temperature twice ("internally separated") and sends a corresponding signal to the engine control unit (ECU) and another signal to the combination instrument cluster.

I think the latter is the case (which is why there are two names for it), but I haven't taken one apart yet.

Quote:

("internally separated") twice the coolant temperature and sends a corresponding signal to the engine control unit (ECU) and the other to the combination instrument?

Correct.

Okay.

If I understand correctly, there is no action required from me. It doesn't matter to me that the control unit reports a combined instrument temperature of 5°C at an ambient temperature of -10°C.
Hauptsache STG Motor bekommt den korrekten Wert, da nach diesem Wert entschieden wird ob und wie lange vorgeglüht werden muss. Is that right?

Have you ever checked if your combined instrument displays the actual temperature? In my case, a (non-critical) part of the sensor G2/G62 is defective.

haithamina