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This winter I’ve noticed cruising on the highway oil is always “cold” unless I modulate the gas pedal spooling up the turbos here and there. Even if it’s up to temp from city driving as soon as I cruise on the highway it drops into the blue zone.
Only cooling mod is a PLM cooler for the intercooler heat exchanger pump circuit.
Whats up? How bad is this? Is it normal for winter and I just don’t remember?
Cruising home tonight after a few minutes on cruise control it dropped to 58. Normally it’s about the same as coolant temp, or at least 70+ and I can easily get it up there again if I don’t just cruise.
I have no mods and I feel, at times, I am in situations like you just described (Oil temp. dropping back down to "blue". in spite of driving the car seemingly enough).
My oil temp while cruising in the winter sometimes drops to ~75C but never as low as 58C. I am on stock ecu tune.
If your car is tuned maybe your tuner altered the oil temp table for cooler summer temps but too aggressive for winter?
When I had my previous car tuned my oil temps dropped a good 10-15C but they would still reach operating temp while winter cruising.
Could also be a faulty temp sensor.
when it's cold enough outside in winter I was always dropping into the blue when highway cruising and that's pretty normal for this engine I recall. I unplug my always on mod for the IC pump in winter
mine does this stock or with any of my three tunes
Last edited by PeterUbers; 01-15-2023 at 12:33 PM.
My oil temp while cruising in the winter sometimes drops to ~75C but never as low as 58C. I am on stock ecu tune.
If your car is tuned maybe your tuner altered the oil temp table for cooler summer temps but too aggressive for winter?
When I had my previous car tuned my oil temps dropped a good 10-15C but they would still reach operating temp while winter cruising.
Could also be a faulty temp sensor.
I bet it’s the tune, my first winter with it.
I can easily get it back up to temp on the highway barely any effort. I’m curios though if cruising at the lower temp does anything bad long term ie: I should pay more attention and drive like a weirdo keeping the temps up? Or just in case I have to floor it? I do floor it a lot…
I have had that same situation since I got the car 3 years ago: in the winter, depending on outdoor ambient temp I often run 20 or 30 minutes of mixed highway/side road and never get past the low 70' C for oil temp. I've had a stage 1 tune on for about half that time and never noticed any difference...
Agree, this is normal. I have a 13 with split cooling, power package and stock. These cars have great cooling and in the winter it takes awhile to heat up. Driving with rpm’s in the 3k range helps. Once warm it sticks in the 190s vs high 220’s like in the summer.
the oil cooling diagram in those cars is isolated from the air intake heat exchanger system so there is no relation with intercooler pump/radiators, also there is no fan on the oil radiator like older AMG cars so the tune or ecu flash cannot alter the oil cooling system, there is an oil to water small cooler (engine water) that is related to engine water cooling, so if the engine water cooling is in the normal region and oil temp in cold region it means everything is normal only the front oil radiator is facing low ambient air temp.
Strange, I was thinking about this topic and another one and they both show up in the forum a day or so later. In temps below 40F, oil temp stays below 159F for 20-30min when driving continuously(highway/roads). And hovers around there. If air temp is 50F or above, then it seems like it reaches normal oil temp, in normal time.
The other topic was about the windshield wiper, cycling 1-2 times before water comes on.
I'm off to diagnose misfire #5 cylinder.
Agree, this is normal. I have a 13 with split cooling, power package and stock. These cars have great cooling and in the winter it takes awhile to heat up. Driving with rpm’s in the 3k range helps. Once warm it sticks in the 190s vs high 220’s like in the summer.
Mine can't stick to warm - as soon as I go on the highway it starts dropping. I can keep it warm with my right foot but as soon as I start cruising again it drops like a rock to "cold". In my pic that started this thread, it was already heated up city driving for a while. As soon as I got airflow on the highway it cooled "too well" to that 58. And the faster I cruise the lower it goes.
I will just copy and paste what i had wrote up almost 5 years ago in another thread, it may shed some light on the situation:
The engine coolant on our cars is controlled by the ecu via a variable thermostat. That means the ecu will go from 0 coolant flow around the engine and rad.. to partial coolant flow only around the engine, then to flowing coolant around the entire engine and rad, then to fully open with max flow, up until the engine is heated up to normal operating temps.
The oil cooling:
Our oil is cooled via a small oil to water cooler, that is under the oil filter housing, and also of course via the oil to air cooler via the front lower center bumper. On cold start, the oil thermostat on the oil cooling rad is closed for speedy heating. Only the oil to water cooler is used.
What most people miss is that our oil pumps have two stages that is also controlled by the ecu aswell.
A low oil flow pressure stage of about 29 psi, which is used for low rpm, partial throttle driving. Not much oil is being pushed around the engine at this stage, and even the piston cooling sprays are shut off, which also reduces heat.
The High oil flow pressure stage of about 58 psi (4bar), which comes on for more aggressive driving and or stop and go, non highway cruising. At this point, the oil pump is pushing all the oil it can everywhere, along with the spray nozzles under the pistons. This will heat up the oil quicker. Of course.
This is both reasons as to why our oil takes so long to come up to temp,
along with why sometimes on highway cruises as I and a few members have noticed, our oil temps actually drop back below the blue 176 (depending on ECU version) mark.
I also would like to stress the importance of practicing low rpms and low load until the engine is up to temp for the engine and turbos sake. ESP if modded.
I will just copy and paste what i had wrote up almost 5 years ago in another thread, it may shed some light on the situation:
The engine coolant on our cars is controlled by the ecu via a variable thermostat. That means the ecu will go from 0 coolant flow around the engine and rad.. to partial coolant flow only around the engine, then to flowing coolant around the entire engine and rad, then to fully open with max flow, up until the engine is heated up to normal operating temps.
The oil cooling:
Our oil is cooled via a small oil to water cooler, that is under the oil filter housing, and also of course via the oil to air cooler via the front lower center bumper. On cold start, the oil thermostat on the oil cooling rad is closed for speedy heating. Only the oil to water cooler is used.
What most people miss is that our oil pumps have two stages that is also controlled by the ecu aswell.
A low oil flow pressure stage of about 29 psi, which is used for low rpm, partial throttle driving. Not much oil is being pushed around the engine at this stage, and even the piston cooling sprays are shut off, which also reduces heat.
The High oil flow pressure stage of about 58 psi (4bar), which comes on for more aggressive driving and or stop and go, non highway cruising. At this point, the oil pump is pushing all the oil it can everywhere, along with the spray nozzles under the pistons. This will heat up the oil quicker. Of course.
This is both reasons as to why our oil takes so long to come up to temp,
along with why sometimes on highway cruises as I and a few members have noticed, our oil temps actually drop back below the blue 176 (depending on ECU version) mark.
I also would like to stress the importance of practicing low rpms and low load until the engine is up to temp for the engine and turbos sake. ESP if modded.
Is the oil thermostat electronically controlled by the ecu or is it a purely mechanical system?
Mine can't stick to warm - as soon as I go on the highway it starts dropping. I can keep it warm with my right foot but as soon as I start cruising again it drops like a rock to "cold". In my pic that started this thread, it was already heated up city driving for a while. As soon as I got airflow on the highway it cooled "too well" to that 58. And the faster I cruise the lower it goes.
Can confirm that in the winter (Canada cold) that on the highway (stock tune 2015 E63S) that the oil temps just hover in the cold/BLUE range If you build some boost and generate some heat the oil temps jump into the warm range right away.
Seems to be how the car runs.
In the city, once warm, even at -35C temps the oil will be warm.
Can confirm that in the winter (Canada cold) that on the highway (stock tune 2015 E63S) that the oil temps just hover in the cold/BLUE range If you build some boost and generate some heat the oil temps jump into the warm range right away.
Seems to be how the car runs.
In the city, once warm, even at -35C temps the oil will be warm.
By hover do you mean somewhere in the 70s or all the way down to the 50s like OP? Cruised through some cold nights here in the GTA and never had my temps drop that low. Usually in the 70s and right back to 80+ if under load.
Maybe OP has a stuck open oil t-stat?
I honestly don’t remember it doing this before is why I’m asking. I always drive with the temps display, always have. I remember it hovering but never 50s. I don’t think. It does raise up right away if I throttle up a bit, but quickly drops down.
By hover do you mean somewhere in the 70s or all the way down to the 50s like OP? Cruised through some cold nights here in the GTA and never had my temps drop that low. Usually in the 70s and right back to 80+ if under load.
Maybe OP has a stuck open oil t-stat?
My oil temps when cruising on the highway at 75 mph (-30C temps) hover around the 65-69 range. Nothing more annoying than seeing oil temps just at 69 consistently for an hour and never getting to 70. For some reason temps hovering at 65 seem easier to accept.
A bit of constant load can get the oil temps up to 70-71, but they quickly drop back down to the BLUE range once cruising.
I took my car to the dealership the first time I noticed this (had video etc) and showed them. They said that depending on the outside temps and the load that temps can sit in the high 50s, low 60s depending on the speed you are cruising at, i.e. I was told that if I was cruising at 60 mph (versus 70-75 mph) that my oil temps would be cooler and that it was nothing to worry about.
They said that they got A LOT of calls from concerned customers about this issue in the past, not surprising when we have 5 months of winter with temps often down to -35C.
What confused me was that my 2015 C63 never had this issue on the highway. It also warmed up quicker on the same drive in to work.
01-14-2023, 09:27 PM
For some reason temps hovering at 65 seem easier to accept.
