Hi All,

 

I seem to experience an odd oil temperature fluctuation on my Scout 1.8TSI.

Oil reaches 106/107 in about 15/25 minutes (depending on season/weather). This temperature is maintained for another 10/15 minutes, then drops to 96 and stabilise again around 98/102.

I've noticed this pattern regardless of the driving condition (city vs highway) or external conditions (it happens both in winter around 10C or in summer at 35+C). 

 

I can't understand what causes the temperature changes. Is there a thermostat that changes anything in the oil circuit? Or is it just how the oil behaves (it's Castrol Edge 5w-40 from the dealer's services).

Having the oil sitting at 98C is fine. 

 

How old is the engine oil and when was the last oil/filter change done?  My next thought (although I'm not too familiar with the 1.8TSI) is that I want to *very carefully* clean out the cooler groups/package at the front of the car.  Make sure that the radiator, oil cooler, intercooler, (transmission cooler/HVAC cooler) are all clear and clean on debris.   This might require carefully disconnecting out the cooling package, disassembling it and making sure there is no blockages.  For reference (and only because I keep on forgetting this) - Australia is still in Summer in January, so sufficient cooling and airflow is important.

Oil is new, last service was November 23. Cooler group is clean. Car is 7 years and 87,000 Kms, and has full history service at the dealer.

 

It has always done this, so this is not a major concern nor it is causing any issue as the car drives well and shows no problems.

I'm just curious on why / what makes this temperature cycle - up to 107C (which is an ok temperature anyway for EA888s according to what I could find in the forum) for half and hour-ish, then drop by 10C, then stabilising up again around 102.

 

 

I found this on a Audi forum - I wonder if that's what makes the oil temperature changing. It makes sense to me.

Absolutely but is yours a generation 3 EA88 engine?

 

Mine isn't but behaves the same, during warm up the oil cooler is actually an oil heater, its temperature closely matches that of the engine coolant due to the heat exchanger, what you and I are witnessing is the normal hysteresis of the mechanical thermostat in the engine cooling system, the water temp gradually rises and overshoots the thermostat operating temperature before the stat opens and it stabilises maintaining a constant temperature.

 

The oil temp display on the dashboard is telling you the truth, the water temperature guage a pack of lies!

Definitely Gen3 engine - code CJSB

Because it is a gen3, assuming correct it will be the electromechaincal thermostat. They are very responsive. Despite their tendency to only last 60k miles. My Golf R regulates temp very quickly you can even monitor servo actuator position on the thermostat as the ECU see's it. My oil temp on motorway varies pretty closely 102C to 107C. Unless I press very hard. Don't tend to monitor coolant temp as closely but from memory it regulates around 103C

If they hadn’t fitted an oil temp readout you wouldn’t be bothering about this. It’s just something else for folk to worry about unnecessarily. 

It's not a worry nor a concern. I observed this behavior ever since, and was just curious to understand why/what makes this happening. 

 

After all aren't we all on the forum to share knowledge and learn more about our beloved cars?

3 hours ago, Mr_Brownstone said:

It's not a worry nor a concern. I observed this behavior ever since, and was just curious to understand why/what makes this happening. 

 

After all aren't we all on the forum to share knowledge and learn more about our beloved cars?

Yes, totally. It does seem strange to me compared to how the 2l ea888 gen 3 shows oil temp behaviour in my car. And normally I would expect it to behave very similarly given the same architecture and common parts. But as @gm73 says,  I wouldn't worry about it... 

hello

I was checking the oil temperature and on the highway it goes above 100 degrees Celcius, sometimes 103, but if not on acceleration is around 98.

is this normal on 2.0 diesel year 2023 ?

mine is anywhere between 90 and 107 degrees depending on weather and driving time but main difference seems to be speed.  When I'm belting along the motorway the temp rises as you'd expect.  I've never had any issues so never worried about it.  1.6 tdi 2016

I know that all EA211 engines have two separate cooling circuits, cylinder head circuit stat opens at ~ 87C and the cylinder block circuit stat at ~ 97C, I have a 2019 Polo 65bhp petrol engine with two stats, and have noticed a similar drop in oil temperature around the time I would expect the cylinder block stat to open, the oil temperature then increases steadily again, no oil cooler on this engine.

 

The 0 to 1500 reference scale below would roughly represent 1500*0.75, 1125secs or 18 minutes or so, the luboil temp dropped ~ 7 minutes after moving off, it eventually rises to 95C to 105C depending on engine load.

 

Edited 30 August, 20241 yr by Johngerard

VW EA211 Engine.pdf