Öltemperatursensor in Ölleitung zum Turbo? | Posts 16+

MichaelJ wrote:

Blind plug that closes the opening where otherwise factory-fitted auxiliary instruments, such as oil temperature sensors, are located.

Are you talking about an Audi B4? And are you referring to the blind plug mentioned by "faz"? That's supposed to be a pretty bad place to put the temperature sensor.

@Wolfi

Yes, I actually own an Audi 80 TDI (B4) myself, with engine code 1Z. Is the blind plug a "bad" thing?
I can't say exactly where it's installed. I saw on charts that VW...
And Audi places the temperature sensor in that location. It is, of course, possible that...
The oil temperature measurement is also influenced by the temperature of the engine block. But.
If VAG uses this location, or if they also install the sensor in other engine control units (ECUs), then...
Tightening the engine block is likely to have a minimal impact.

Maybe I'll manage to take some photos today, and I'll post them here.

Regards,

Michael.

Hello!!

Well, interestingly, there are different opinions regarding the installation locations, and also about the purpose of them.

@MichaelJ

I'm just having a friend machine an extension for the oil pressure sensor.
"On which engine models is the oil temperature sensor located?" What temperatures are you getting?

@Everyone
AFAIK, there are 2 cases where oil temperature control is important:
If the oil temperature is below 75°C, you should avoid demanding high performance and high RPMs.
2. The oil temperature should generally not exceed 130°C.
(please correct me if I'm wrong)

I know this is going to be a bit of a nitpicking exercise, but:
The two scenarios can be covered or uncovered using a sensor, either before or after the oil cooler. However, scenario 1 is important every day, while scenario 2 (at least in my experience) is extremely rare. And if the temperature is really higher than usual, you can definitely notice it.
My conclusion is that, after the oil cooler, the best location for installation is...

Thank you for your efforts.
If I have everything together (including the LDA), I will write a technical article, if desired, explaining how I did it.

Regarding the oil pressure sensor:

You don't need an adapter. Screw in the oil pressure sensor instead of the warning sensor, 0.75 bar - warning contact instead of 0.3 bar - warning contact.

If you don't believe me, here's a picture:
[img][/img]

"Photograph taken from a high-angle perspective, showing the fuel injection pump and the dipstick." From left to right, you can see the oil pressure warning sensor (0.7 bar) on the oil filter-oil cooler flange, followed by the oil pressure line to the turbo, and diagonally, the dual sensor for auxiliary instruments.http://home.arcor.de/f.bichlmeier/mforum/Oeldruckgeber.JPG{MARKER}

My brother drives an Audi B4 2.0 16V gasoline car, which comes standard with additional instruments. Here, the sensors are installed in the same way, with the difference that, instead of an oil pressure line to the turbo, the oil temperature sensor is located in the bore.
An alternative is the blind plug on the block. Alternatively, you can remove the 0.7 bar pressure sensor, leave the cable disconnected, and instead install the oil temperature sensor.

Hello!

Thank you for your efforts, faz!!
That helps me a lot!

I would appreciate it if others would share their thoughts on the topic of the installation location.

Hi,

I think all the necessary information has been provided, but there's one more thing.
Do you really think that the factory-installed location of certain sensors indicates the best place to take measurements?
Even with small production runs, the businessperson usually has more influence than the engineer, and this is even more true for mass-produced products like cars. In consumer products, a lot of cheap, inferior materials are often used, even though technically better alternatives exist. The average user will never even notice, and the consumer ultimately bears the additional costs.

Greetings.
dieter

Hi,

I completely agree with Dieter!

The standard location for the temperature sensor in the Ibiza is behind the outlet of the oil/water heat exchanger. This means the temperature being measured is that of the oil *after* it has transferred excess heat to the water. In my opinion, this is useless because it doesn't tell you how hot the oil actually got, but rather how much it has been cooled. One could draw conclusions from the difference between this temperature and the water temperature, but one doesn't actually know the real water temperature from the readings.

Best regards,

Jan is still very satisfied with his homemade probe sensor.

Has anyone actually read my thoughts on the topic of the installation location???

Quote:

@All AFAIK, there are 2 cases where oil temperature control is important: If the oil temperature is below 75°C, you should avoid demanding high performance and high engine speeds. 2. The oil temperature should generally not exceed 130°C. (please correct me if I'm wrong) I know this is going to be a bit of a nitpicking discussion, but: The two scenarios can be covered or uncovered using a sensor, either before or after the oil cooler. However, scenario 1 is important every day, while scenario 2 (at least in my experience) is extremely rare. And if the temperature is really higher than usual, you can definitely notice it. My conclusion is that, after the oil cooler, the best location for installation is

.

When the temperature after the oil cooler is measured, it indicates when the oil reaches the important temperature of 75°C for lubrication. The temperature reading before the radiator is inaccurate because the oil is being heated by the coolant, even when the oil is still cold.
IMO, it's more important to avoid using cold oil than hot oil, because cold oil is less common.

Since the oil is heated by the water-oil heat exchanger during the warm-up phase, you can be sure that the measurement you take in the tank will be accurate.
If you're in such a hurry to get your tractor running that you don't want to wait for the oil in the pan to warm up, then you'll probably have to measure it somehow.

Is that really a comprehensive treatment of the subject, though?

Greetings.
dieter

dieter wrote:

But that is probably really a comprehensive treatment of the subject, or ?

Absolutely!

Hello, I have an ALH engine, and it reaches oil temperatures of up to 140 degrees Celsius when driving at full speed on the highway on warm days. This only requires driving at maximum speed for about 15 minutes. At normal highway speeds of 140-160 km/h, the oil temperature is around 120 degrees.
Is this normal, or not? I think 140 degrees is quite high. By the way, it's being measured with a VDO sensor and display, instead of using the oil drain plug.
If the oil temperature is too high, what could be the cause?

I have the original Oeltemperaturanzeige (oil temperature gauge) in my car. During normal highway driving at 140 km/h, it reads 120°C. If I accelerate hard or drive with a trailer, it can easily reach 140°C. The "red" zone doesn't start until 160°C, so there's no need to worry...

The highest temperatures are reached in the operating range near the piston rings, and after the engine is turned off, in the turbocharger. Both areas are not easily measurable.
If an oil cooler is present, there's a reason why the temperature is measured behind it; this allows for a comparison with the oil pan temperature in other engines. There, they don't measure just any peak value from the rebounds, but rather the value at which the oil re-enters the circulation system.
"At 140°C, our TDI engines are less of a concern than gasoline engines because a significant amount of heat comes from the intercooler, which keeps the absolute peak temperature lower than in the engines mentioned."

Hello.

I'd like to briefly explain how these temperatures are determined during the development process at UTM.
The oil temperature is always measured in the oil sump, specifically in the oil pan, because this is where the maximum (and reasonably measurable) temperatures occur.
When it comes to oil, it's not the minimum temperature that's important, but the maximum temperature, which indicates the point where the lubricating film breaks down.

The oil warning temperature on our machines is 150°C. From here on, things get critical.
Operating the engine oil at 140°C significantly reduces its lifespan and lubricating ability.

However, the engine's overheat protection system is always referenced to the water temperature and typically operates around 120°C, depending on the manufacturer.

Best regards, Jochen.