[Aussie]

I don't think what you did was a good idea. The engine needs to run hot enough for efficiency and without a re-tune, you might see a drop in fuel economy. Furthermore, engine oil needs to operate above the boiling point of water to prevent condensation and water contamination from building up. That point is 212F. You running the thermostat below that temperature means you'll likely also need to change oil more often since oil will not reach above the boiling point of water, which may cause it to break down more quickly.

A 195F thermostat may have been more appropriate.

This is interesting. My daughter has a 2015 1.6T and the engine runs around 105C. I have a 2012 diesel and it runs around 80-85C summer or winter. Both our cars have the digital temperature displays and the diesel gauge starts to move at 50C, not sure about the daughter's car as I don't drive it much. The heater starts working before the gauge starts moving.

 

[Aussie]

A friend had a Mini (original1966) and had 2 temperature gauges fitted. One for water and the other for oil. The water ran at 180F and the oil went to 250F, even though he had an oil cooler. I know the diff and transmission are in the sump, but the oil still runs hotter than the coolant in most cars that I have owned.

 

[Aussie]

Unless you have an oil temperature gauge, what are you basing your oil temperature on? Unless things have changed it has been my belief that oil temperature is not influenced very much by normal engine temperature. After all there is an oil cooler in the radiator for the transmission. Doesn't that then indicate the the oil is hotter than the coolant?

 

[Aussie]

OIl gets it's heat from the engine. How can you make it hotter then the engine? Water heats up faster then oil.

Oil temperature is not connected to water temperature, the combustion of the cylinders is the main source of engine temperature. The old air cooled engines still heated up the oil because all the moving components generate heat. The oil in the gearbox (manual) and diff in a rear wheel drive race car require oil coolers to stop the oil overheating and failing.

 

[Aussie]

Air cooled is a different beast and yes oil is connected to water. It heats and cools along side with water.

Please explain the high temperature the differential oil in a RWD drive car can reach? So high in fact that in a race car the diff usually fails if the oil cooler stops working.

I found this on line: As you can see it would cause problems if the coolant reached these temperatures. As I own a diesel Cruze i know the coolant sits around 80C and my daughter's petrol 1.6T Cruze runs at over 100C.

For non-synthetic motor oil, the traditional approach is to try to hold oil temperatures between 230 and 260 degrees F. For full synthetic motor oil, maximum can exceed 300 degrees. In all cases, less than 212 will cause water buildup in the crankcase.

 

[Aussie]

as stated earlier ~~~ this mod is not for everyone. i am sharing MY temps and MY engine oil analysis and MY emissions regarding this mod that i have done to MY car.
please start another thread debating YOUR info you want to share.

I apologise as I guess it is my fault we got a little bit off topic. Back in the 80's when my kids were little I had a Toyota 8 seat mini van and the temperature of the engine used to gat higher than I was comfortable with in heavy traffic. It gets really hot in Australia so I asked around if anyone knew how I could get my engine to run cooler. I was told that a Volvo thermostat was set at 170 and the Toyota was at 195. By grinding down the Volvo one to make it fit the Toyota the cooling system problem was solved. This is the reason I got interested in this thread in the first place.

 

[Aussie]

Update: since doing this mod about 4 mos and 4000 miles ago, i have had zero problems. Its now winter and i was curious as to whether the heater would be able to provide as much heat as before. Yeah. It does.

I have a 2012 diesel ans a few days ago the outside temperature was over 40C and the engine was at 78C. Today it was a pleasant 23C and the engine was at 82C. The a/c is set at 23C, so no heater was involved, so my guess is that as the diesel (in Australia anyway) has 2 fans it must simply supply more cooling in hot weather. I suspect one of the fans runs constantly when the a/c is on. My daughter's 1.6T which runs at 105C has just had a new thermostat at 90,000km.

 

[Aussie]

I'm not sure what you are asking here.
But 176-183°F seems to be working great for me.
Fuel economy is better than ever, and my heater will end up running you out of the car if left at max...

I agree, I have digital temperature in my DIC and the round gauge starts to work at 51C, but even before that I am getting reasonable heat into the car. While 2-6C may not seem cold for winter it is cold enough to need a heater. I have automatic a/c and leaving it at 23C all year round works fine even at 40+C. By the way the Australian diesel Cruze doesn't have an electric heater and the engine runs at about 80C but takes a long time to get there in winter.

 

[Aussie]

Could the replacement of the thermostat break the fan?

No.

 

[Aussie]

Before you decide to perform this modification, read this: measure 1.4 thermostat resistance question, P0599

Heat and pressure are the enemy in a cooling system with many plastic components. The thermostat is a point of failure in the 1.6T engines. There is now available a metal housing for this engine which has proved to be more reliable. Perhaps this is available for the 1.4T as well?

 

[Aussie]

The oil temperature is not really related to the coolant temperature and usually runs hotter than the coolant. If this wasn't the case why do performance cars run separate oil coolers? A friend had an original mini minor and fitted a gauge that had a switch that went from the coolant to oil temperature at the flick of a switch, so the same gauge was used for both. Coolant ran at 170F when cruising and the oil ran at 250F when cruising. I know the transmission was in the sump, but it was also ribbed alloy to help with cooling.