Kühlerlüfter auf Funktion prüfen? | Posts 16+

@ulf

Wow... I thought the days of Wartburgs with undersized radiators were long gone. I've been working on cars since the early 80s. I've only encountered a faulty thermostat once. And it was so defective that the fan was constantly running. That was in an 1987 Audi 80 with well over 280,000 kilometers on the clock. Since I've been working with TDIs (since around 1995), I've experienced many faulty thermostats, but never!!!! a faulty thermostat switch. I know several people who ride motorcycles and drive their vehicles right at the performance limit. Even they don't install such an over-cautious switch. Caution is good and helpful, but you shouldn't overdo it!

rinderwahnsinn wrote:

[And I know of 3 cases where the head gasket blew out because the fan was mechanically blocked. That won't help you, even with your

.
However, this allows you to turn on the fan intermittently and listen to see if it's still making noise.

Quote:

I have a separate switch specifically for paranoia. Thermoschalter (thermostats) rarely fail, and newer vehicles often warn of overheating with a light and sound signal. Moreover, this system is even redundant because the temperature sensor also functions as a combined sensor (KI / EDC).

There's no more redundancy in my Polo: only one NTC sensor is connected to the EDC, which transmits the water temperature via CAN.
And the "Quäke" + lamp on my car only turns on when the temperature reaches just below 130°C .

And the Quaker + lamp in my car only turns on when the temperature reaches almost 130°C

Then you might want to revert the tuning to eliminate a *potential* source of overheating.

I certainly don't have paranoia. During that exceptionally hot summer, the engine struggled to reach a water temperature of 100°C, and that was after driving 10km uphill. You won't need the fans while driving anyway, but if you enjoy being stuck in traffic...

CU

rinderwahnsinn wrote:

You probably won't need the fans while driving, but if you enjoy being stuck in traffic...

No, definitely not.
But sometimes, it just happens.
For example, 35°C in blazing sunshine, stop-and-go traffic, such as on the Albaufstieg highway, where you move forward just 5 car lengths every 2 minutes, and with a slight tailwind, so that the radiator receives as little airflow as possible.
"In my opinion, gasoline engines would overheat within 5 minutes at most if the fan wasn't working... what do you think, how much longer would a TDI engine stay 'cool' in the same situation?"

But sometimes, it just happens.
For example, 35°C in blazing sunshine, stop-and-go traffic, such as on the Albaufstieg highway, where you move forward just 5 car lengths every 2 minutes, and with a slight tailwind, so that the radiator receives as little airflow as possible.
Gasoline engines, with the fan stopped, would likely overheat within 5 minutes at the latest... What do you think, how much longer would a TDI engine remain 'cool' in the same situation?

Is anyone dreaming here?

Let's see if you can get your TDI to overheat, I haven't managed to do that yet. 'During our great summer two years ago, with temperatures reaching a scorching 42°C under the intense sun, my AWX didn't overheat (it stayed at a constant 90°C), and it even ran for about 2 hours in the full sun for testing purposes. (Please don't judge me as environmentally irresponsible; there was no other way to test it).'

'How Mr.' Cow madness indeed! I mean, remove the tuning, as that's one less heat source. :hihi:

Julian wrote:

By removing the tuning, a heat source is eliminated.

Then I'll just remove the two heavy fans; at least that will improve the power-to-weight ratio .

But, according to your explanations, if TDIs cannot overheat even under extreme conditions (meaning that the heat dissipation through radiation and convection by the partially insulated surrounding metal parts is apparently sufficient): Why do cars without air conditioning even have radiator fans, if cost savings are always a priority ?
Is this only related to the fan running after a certain time, specifically when someone accelerates to the maximum speed (Pmax) on a parking lot and immediately turns off the engine after 5 minutes?
Then, it would still be possible to eliminate the thermostat switch in the radiator .

Hi,

Quote:

But if, according to your explanations, TDIs cannot overheat even under extreme conditions, why do cars without air conditioning have radiator fans at all, especially when cost savings are prioritized in every other aspect?

"I've also experienced the fan turning on even without the air conditioning. This happened after a test drive with a trailer in an outside temperature of 30+ degrees Celsius. After about half an hour on the highway, I drove a short distance through a town (I turned off the air conditioning after the highway exit)... and when I stopped in front of my parents' house, the oil temperature was still at 115 degrees, and the fan was running – although not at the level that's activated when the air conditioning is on."

So, it's feasible... although I think the extremely cramped engine bay of the 6K also plays a role. Perhaps the climate control system had an influence... in any case, it was quite warm.

Edit/Supplement:

Quote:

"I know of three cases where the head gasket blew out because the fan was mechanically blocked."

I don't know what it looks like in the climate-controlled TDI models... but I have a really big double fan there. If one of them is blocked, the other one should still be perfectly sufficient.

Best regards,

Jan.

Why do cars without air conditioning even have radiator fans, especially when every penny is being saved elsewhere?


So that you can build something...

I would attribute this more to a standardization strategy. It's cheaper to build/order the fewest possible types of cooling units rather than having a specific one for each engine type. For example, the Audi A4 8E uses a single cooling unit across its entire engine range. It's advantageous for me that the 4.2-liter V8 requires different air intake conditions than my AWX engine.


Is this only related to the fan running after a certain time, specifically when someone accelerates to the maximum speed (Pmax) on a parking lot and immediately turns off the engine after 5 minutes?
Then, it would still be possible to eliminate the thermostat switch in the radiator .

Does your oil temperature ever exceed 95°C? The engine really doesn't give a d***.

Jan6K wrote:

I don't know what it looks like in the TDI models without air conditioning... but I have a really big double fan there. If one of them is blocked, the second one should still be perfectly sufficient.

Okay, I also have 2 fans (of different sizes) ... the double pack seemed a bit oversized to me even before this thread.

Hello,

Diesel engines, including those with TDI technology, have a high air intake even when idling, unlike gasoline engines. This allows them to be cooled "from the inside," and as a result, they don't get nearly as hot as gasoline engines do in traffic jams. I suppose you can manage without a fan even if you don't have air conditioning.

Sincerely,
Christian

Okay, to check the fan: Disconnect the connector from the temperature sensor on the radiator.
One of the three cables must have a constant positive voltage; it's best to check this with a test lamp against ground.
If you bridge this positive wire with a cable (don't use a cable that's too thin, otherwise it will get hot) to one of the other two cables, the fan will start. It will run at either the first or second speed. If it does, the vehicle will maintain an idle speed of approximately 3,000 RPM with the thermostat switch connected. Pay attention to the temperature gauge! The fan will typically switch to the first speed around 95-97 degrees Celsius, but this may take some time. You cannot test the second speed in this way; it usually only activates under heavy load. G3 WITHOUT Air Conditioning.
Sure, here's the translation:

'Hello' or 'Greetings'
edz

Hello,

I also addressed this topic some time ago.

Okay, I'm ready. Please provide the German text you want me to translate.

Regards,

Tobias.

Hello fellow DIY enthusiasts,
First of all, thank you for the answers...

Today, I had time to check my cooler fan.
Here's a little guide for people who are experiencing the same things as I am:

~~~ I ASSUME NO LIABILITY FOR DAMAGES OF ANY KIND!!! ~~~

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Here is the connector that goes from the thermostat switch to the fan.

[img][/img]
It looks like this from above.

[img][/img]
A cable to bridge the connector pins, not too thin, as the fan already draws a few amperes.

[img][/img]
By measuring the terminal 30 (2 Volts), you can find it. The 12 V must also be present without the ignition being turned on. The other two contacts have no voltage.

[img][/img]

[img][/img]
Here's the pinout diagram.

[img][/img]
Now, bridge the contacts labeled 'Kl. 30' to 'Fan speed 1' and then 'Kl. 30' to 'Fan speed 2' one after the other. The fan should start running after each connection. BE CAREFUL WITH YOUR FINGERS!!!

[img][/img]


The plug on mine had the following wire colors (this may not always be the case):
RED: Terminal 30 (2 Volts)
RED/WHITE: Fan speed level 1.
RED/BLACK: Fan speed level 2.


Greetings from sunny Franconia,
Mathiashttp://www.8ung.at/mweid/TDI/1.jpg{MARKER}http://www.8ung.at/mweid/TDI/2.jpg{MARKER}http://www.8ung.at/mweid/TDI/3.jpg{MARKER}http://www.8ung.at/mweid/TDI/4.jpg{MARKER}http://www.8ung.at/mweid/TDI/5.jpg{MARKER}http://www.8ung.at/mweid/TDI/6.jpg{MARKER}http://www.8ung.at/mweid/TDI/7.jpg{MARKER}http://www.8ung.at/mweid/TDI/8.jpg{MARKER}