Location needed for oil temperature sensor installation

Hello everyone,

I plan to install an oil temperature gauge on my 2.0 TDI 16V BKD engine.
According to what I've read, there are various possible locations for installing the sensor, ranging from the oil drain plug to the oil filter and even the dipstick.

The oil drain plug is not an option for me due to the poor accessibility and the need to drain the oil.

I don't really like the dipstick either, because it would tie me down and make it difficult to check the oil levels in the future.

Now the question remains: Will this solution, involving the oil filter base or adapter, work with this machine?

Then I have another idea: to integrate the sensor into the lid of the filling opening. What do the experts think of this solution? Or can an exact temperature be measured there?

Best regards,
Micha

Quote:

The oil drain plug is not an option for me due to the poor accessibility and the need to drain the oil.

These, and the dipstick, are the only places that provide reliable data (without requiring much technical expertise).

How unreliable is a measurement taken at the cylinder head cover?
Or, to put it another way: if there is any bias at all, in which direction is the measurement result skewed when measuring at the ZK (presumably referring to a specific location or device)?

Sure, here is the translation of the text from German to English:

'Micha'

Does the engine not have an oil pressure sensor somewhere that feeds data to the instrument cluster?
There, one could use a T-fitting, connecting the oil pressure sensor to one port and the oil temperature sensor to the other.

I hope you can follow along with the T-junction. I mean the original VW part, like the one used in a G60 engine.

As a Plan B, a small NTC/PTC thermistor could be mounted on the oil line coming from the turbocharger.
However, the measurement wouldn't be 100% accurate, but it does work.

I'm using an NTC thermistor that I've fastened to the heating water hose with a cable tie to measure the temperature of the coolant water for my homemade auxiliary water pump control system.
So far, it's working perfectly. The pump runs until the water temperature drops below 80°C.

Quote:

How unreliable is a measurement taken on the ZK cover?

100%.


Without significant effort or technical modifications to existing systems, only a dipstick or an oil drain plug remains as an option.

A T-fitting is also possible, but it may be affected by heat radiation or air currents, especially if it is installed outside.

Without much effort or technical intervention beyond what already exists, only a dipstick or an oil drain plug remains.

Okay, understood!
I took a look at the dipstick, but it probably won't show anything either, because the tube it's connected to has two bends.

Okay, let's go back to the ZK (oil cooler): just theoretically and hypothetically speaking, does the oil up there have a higher or lower temperature than the oil in the oil pan? I could potentially screw a 10mm aluminum rod with a blind hole into the ZK cover, which is made of plastic, and have the end of the rod submerged in the oil bath. I can then insert the sensor into the bored hole from the outside... it should work, or are we going to get a simple 'NO' again???

Best regards,
Micha

Hi,
For my car (which is a bit older), there's a sport version that includes an oil temperature gauge. The sensor 049919563B is attached to the oil cooler via a separate M10x1 thread.
Perhaps your car has the same feature; check your owner's manual. You can also have the parts located for you by the dealer. Perhaps there is at least a threaded connection.
Possibly, the oil temperature can also be read in the MFA (Multifunction Display) or in one of the measurement blocks, in which case there is also a sensor.
If not, I would see if a T-piece from a different model or a custom-made one could be installed. Then the plugs and cables won't be in places where they're likely to cause problems.
hg
Herbert.

Quote:

....or is it going to be a simple "NO" again??? icon_smile.gif

Yes. Taking someone's temperature in your pocket --> that's not possible.

Quote:

Accordingly, you can have the parts selected for you at the dealership. Perhaps there is at least a threaded connection. Possibly, the oil temperature can also be read in the MFA (Multifunction Display) or in one of the measurement blocks, in which case there is also a sensor.

I had also considered that, but it involves an effort/investment that he's not willing to make. The probe may not fit the pressure gauge, etc.

I have an oil temperature sensor installed. I don't want to tap into that line, as it could affect the MSG (Message Sequence Number), but rather perform a second, redundant measurement.

Regarding the effort involved: I'm not afraid of putting in a certain amount of effort, but I'm hesitant about the work that would require a lift platform, simply because one isn't available. I would like to do this at home, where I have my tools and materials to make certain things, but unfortunately, I don't have a home office.

Regardless of any pocket-sized measuring devices, I understand that measuring the oil temperature in the transmission won't help me.

Therefore, another idea that was mentioned previously seems quite useful to me:

I'm referring to the measurement on the oil line leading to the turbo. I just took a look at mine on my BKD engine. It's an 8mm aluminum tube to which I could securely attach a cylindrical sensor with a diameter of 4mm and a length of 3cm, along with a 3cm wide brass clamp. Then the measurement result should be relatively accurate, as a good thermal contact is established in this way... or is it just another way to line one's pockets ?

Best regards,
Micha

Hi Micha,
That's just pocket change. Your temperature sensor must be located in an environment where the oil temperature is present, meaning it must be immersed in the oil bath or in the oil flow.
hg
Herbert.

Normally, the 2.0 TDI engine should have a tapping point from the factory, and at least the newer 2.0 TDI engines in the Octavia have an oil temperature display in the on-board computer.

That's pocket change.

Oh, Manuuuu.
I'll still give it a try, since the effort involved is relatively small!
Furthermore, I believe that the wall of the turbo pipe, acting as an additional insulator, will not create a significant measurement difference compared to a direct measurement in the oil bath. I can ultimately compare it to the originally installed sensor, which I can read using VCDS.

If the difference remains constant across the entire measurement range, say around 2-4 degrees, I might be able to compensate for this offset using the measuring device itself...!?

Practice makes perfect!

Normally, there should be a factory-installed tap for an oil temperature sensor on the 2.0 TDI engine, at least the newer 2.0 TDI engines in the Octavia have an oil temperature display in the onboard computer...

Yes, there's also a combined pressure and temperature sensor available for the oil pan.
However, it's not available in the small MFA device that I have installed.
'I also think it's better to have a separate ad for each 'div'.' It's frustrating to have to navigate through thousands of menu levels just to see the values while you're driving.
I already have an LDA (likely referring to a digital display) mounted on my dashboard, and I want to have an oil temperature gauge there too!

Sure, here is the translation of the text from German to English:

'Micha'

I just have one more question for the experts among you.
On my BKD engine, there's a pressure line running from below the oil filter to the turbocharger. Is this the supply line to the turbocharger, or the exhaust line from the turbocharger? Does anyone know?

Sure, here is the translation of the text from German to English:

'Micha'

Zuleitung

Since the oil is pumped through the block, which is heated to approximately 90°C, there's no need to measure the oil temperature, as it will be similar.

The highest oil temperature will occur in the oil pan because this is where the oil is heated by the blow-by gases and the piston cooling system.

Best regards, Rainer.

Okay, then I'll find a suitable spot on the oil pan where I can mount the sensor.

Have a good evening, and thank you for the stimulating discussion.
Sure, here is the translation of the text from German to English:

'Micha'

In my opinion, the oil temperature is... Advertisement not required if:

• Oil temperature after 15 minutes of continuous full throttle (very rarely possible, e.g., on the A7 if you're lucky).
• Drive up steep inclines like the Kassel Mountains or the Brenner Pass with a heavy trailer.

The temperature does not exceed 130 degrees. This can be read very well using VCDS if an oil sensor is installed.

I completely agree with Rainer .

Otherwise, it's a matter of personal taste and a way to ease one's conscience.