Oil Temperature: How to Check & Fix

I'd be interested in knowing some temperature readings, such as what the oil temperature is at a certain speed, and how the coolant behaves in relation to that.
Then please also specify the type of engine, e.g., TD, naturally aspirated diesel with or without turbocharger, with or without oil cooler, with or without tuning cone. And please also let me know what type of engine oil you use, e.g., 10w/40.

Thank you, and best regards, Mark.

Good idea, I'd also be interested in that.

Okay, Passat 35i TDI (1Z), without tuning, without AGR valve, without MAF sensor.

'Under normal driving conditions on country roads...'
Coolant temperature around 70°C-75°C.
Oil temperature: 70°C - 72°C.

Highway, full speed ahead.
Coolant: 85°C - 90°C
Oil temperature in summer: maximum 114°C, otherwise around 100°C.

I couldn't get the fan to turn on back then, when I was running pure diesel fuel through the system.

'For my Golf III TD, with the AAZ engine, 1.9L, without AGR (Exhaust Gas Recirculation) or intercooler, and with a boost pressure increase up to a maximum of 0.9 bar.'

In the city, the oil temperature is 80-90°C.

'Under normal rural (country road) conditions...'
Oil temperature: 90 - 100 °C.

Highway at 140-150 km/h.
Oil temperature: 115°C.

I've never pushed the car to its full potential on the highway because the oil pressure hose needs to be replaced (it's slightly leaking, but it's already been ordered).

Only on Bosch's dynamometer did we test the engine at full throttle, and the water pump fan turned on, and the water temperature was in the middle! The oil temperature was a maximum of 115°C, and the power output is not 75 horsepower, but 95 horsepower.

I've noticed that when the oil temperature is consistently around 100°C, I don't have any oil consumption. However, as soon as it exceeds 110°C, I start to experience oil consumption, but it's still in relatively small amounts.

And my coolant temperature is always in the middle, even in winter!
What kind of engine oil do you use? I use 10w/40.

@docsnyder

'Is the coolant temperature really that low when driving on the highway?'
I had that problem for a while too. I think there's something wrong with the thermostat. Ideally, you should be getting around 90 degrees Celsius on the highway or anywhere else.

I have a 1.9 TDI Passat wagon that's been tuned with a chip, running 1.1 bar of boost, using injectors from an A6 TDI with 103 kW (216 injectors), modified pressure pipes, and the turbocharger has been optimized for the setup.

Normal city driving: approximately 80-90° depending on the outside temperature.
At approximately 160 km/h, the temperature is around 105-110°.
Under full load, the oil temperature can already reach 125-130°C, especially in the summer. This is without an oil cooler and using 10W40 oil.

hi,
Yesterday evening, I went to a nightclub (in the Münsterland region) and checked the oil temperature.

I drove at approximately 200 km/h for about 12 minutes, and according to the MFA (Multifunction Display), the temperature rose to 118°C before the car stopped. The outside temperature was approximately 10°C.

At approximately 210 (presumably a temperature or pressure reading), the indicator was already moving towards 130°.

At approximately 180 km/h, it took about 15-20 minutes for the temperature to rise above about 112°C, with a total of 3 people inside.

It's a Passat Variant 1Z, with a chip, injectors from an A6, no oil cooler, and using 10W40 oil.

2.5 AKN engine, original 2LLK cooling system and oil/water heat exchanger. Water temperature is always around 90 degrees Celsius. Oil temperature is around 90 degrees, and can reach up to 110 degrees during prolonged high-speed driving.

@joergs

Hm, if I read this, I could really think that something is not right...
I once completely blocked the radiator with a thick piece of cardboard during the winter, similar to what you might do with a Trabant car. However, it didn't change the temperature at all.
By the way, I also use 10W40.

@doc

It looks like it's really the thermostat! As I said, I've experienced similar behavior. On the highway, the temperature also reached 90 degrees, but only when driving at full throttle. It's quite a stressful job to replace the thermostat because you have to disassemble quite a bit, and it's not easy to access.

edit: After the change, the speed limits are around 90 km/h on both country roads and in the city, even when driving moderately.

'On my ALH engine, the oil temperature never exceeded 110°C (using 5w-40 oil) under full load during a long drive (~300km). In the city, it's around 85°C.'
When driving comfortably, the temperature was only between 70-80°C, depending on the outside temperature.
Replacing the thermostat didn't make much of a difference.

http://www.ralfhandel.de/temperatur.gif

Hello everyone,
Actually, I also wanted to log my temperature readings today, especially the correlation between oil and water temperature.
Unfortunately, I haven't been able to find any corresponding measurement blocks. There are, in my opinion, three possible explanations for this:

1. my personal inability.
2. My combination of engine control unit (038 906 018 A) and engine code AGR does not offer this possibility.
3. The shareware version of VAG-COM (DRV 302.2) does not support this feature.

Which of the three options is correct?

I immediately found measurement blocks for coolant temperature, intake air temperature, and fuel temperature, but no other temperature readings.
What's the reason? Does the AGR engine perhaps not have a built-in oil temperature sensor? I would be very sorry to hear that.
If I've understood correctly, some people in their posts are also distinguishing between intake air temperature and charge air temperature, which makes a lot of sense for assessing the efficiency of the intercooler. Unfortunately, I haven't found any such measurement blocks either.

Bitte klärt mich auf. Thank you!!!

Regards,
Alex.

Okay.

Oil temperature sensors typically only have models with a variable service indicator. In these models, the temperature is measured to calculate oil degradation.

This sensor is exclusively processed by the instrument cluster; the engine control unit (ECU) has no information about the oil temperature!

The temperature of the intake air is not measured; this is not necessary in turbo engines. Therefore, its temperature can only be estimated based on the display in the MFA (or Climatronic). The EDC only measures the temperature of the charge air at the outlet of the intercooler, but it could potentially query the external temperature sensor via CAN. However, this is actually not necessary.

CU Gremlin.

Oil temperature sensors typically only have models with a variable service indicator.

But my MFA (Multi-Function Display) can also show the oil temperature. And I still have a fixed service interval (model year 1994). Or was that only related to the EGR (Exhaust Gas Recirculation) system? Then I'm sorry...

@Gremlin:
I'm considering adding an oil temperature sensor to my engine (MKB AGR).
Where is this sensor installed, for example, in the automatic models? Is there a thread on the oil pump or filter flange that is intended for it?
Could I potentially easily install the standard sensor that comes with the automatic version onto my engine and connect it to a homemade display or a component purchased from an accessory retailer?
Perhaps there are some tips and suggestions here regarding sensors and display instruments. Has anyone ever done this before?

Are the VAG temperature sensors actually NTC thermistors?

I once retrofitted an oil temperature gauge to my old gasoline-powered car. It was a modified oil drain plug with an integrated temperature sensor. It worked quite well, but I don't think it's a very practical or professional solution!

Regards,
Alex.

Hi,

*dusting*

I've resurrected this thread again because my "tests" from the weekend would fit in perfectly here.

I have a homemade temperature gauge that works quite accurately (the error in boiling water is less than 1 degree), and it therefore provides a fairly reliable reading of the actual temperature in the oil pan, without being affected by the airflow (which cools the metal) or the ambient temperature.

Normally, in the city and on urban highways, up to 100 km/h, the temperature gauge remains between 92 and 100 degrees Celsius when the engine is warm.

This weekend, I drove longer distances on the highway for the first time since the gauge was installed (twice, 530 km each time), and of course, I carefully monitored the oil temperature.

The outside temperature was between 8 and 14 degrees Celsius. There were 4 people (with a combined weight of 280 kilograms) and a bit of luggage.

While driving normally at around 140 km/h, the temperature was 110 degrees Celsius. When driving at 160 km/h for an extended period, the temperature also rose to 115 degrees Celsius.

If I stayed within the range of 160 to 180...190 km/h, the display showed 120 degrees. However, with a longer period of full throttle (speedometer reading 200...210 km/h, briefly reaching 215 km/h downhill - realistically about 8...10 km/h less), the temperature would rise to 130 degrees.

Given that most series sensors are located behind the WT (water tank), I think this value is consistent with the others. What do you think?

The oil is 5W40 and came from the Seat dealership. The engine has now been driven 36,200 km.

Best regards,

Jan.