Oil Temperature

[930.engineering]

Thanks for the flowers. Of course discussions are repeating, that's the nature of car forums.

On most engines the oil temp sender is sitting either on the oil filter bracket or the oil pan,
IF it has a sender. Of couse the location makes some difference, but does it actually matter?
You have to find out what's normal for your car, which isn't difficult, then you'll easily be able
to assess deviations from normal. My Mini lacks this sensor, while my GTI has a dual-purpose
sender for oil level and temperature. There's a minor deviation between what's displayed on
the infotainment screen and what OBD reads of just 2 or 3 Kelvin - pretty much insignificant.

.

 

[Kira]

Aside from "rounding considerations" mentioned above, does the "accuracy" of a factory gauge escape scrutiny?

Three cheers for mass production but are the cheap gauges on a dashboard to be trusted? I mean 220 vs, 230?

 

[OVERKILL]

I mean think about it almost every vehicle seems to have the same oil temperature reading. LOL Wow OK that is also to say that every ECU is programmed the same in everything. Its NOT!

Of all the vehicles that I"ve owned that have had oil temperature gauges (and that's been a few) they've all read different oil temperatures depending on operating condition. Some of my most recent observations have been posted on here.

That said, plenty of these vehicles have oil/coolant heat exchangers, so the oil temperature will naturally track closely with coolant temp, which is what I've observed in my RAM and Jeep.

The vehicle with the most variability in oil temp was my E39 M5, which had a large plate cooler in the valley. This was thermostatically controlled but would, due to the size of the sump, pan, and surface area, remain inactive in "typical" driving conditions. It would come up onto the thermostat when you were stuck in traffic or beating on it, its opening was obvious as the temp would cross 100C and then all of a sudden drop as the oil started going through the cooler.

Given that the purpose of the sensor and gauge combo is to provide bulk sump temperature, this being provided shouldn't be surprising. Yes, temperature at the end of the crank would be higher, it would also be much higher coming out of the turbo bearings. There are myriad locations where the temperature is going to deviate significantly from bulk, but the idea is to control and monitor bulk sump temperature because that's the temperature of the oil that's being fed to these areas. I think that's a pretty reasonable expectation from a production system where feeding Joe Average temperatures from multiple locations is likely going to be more confusing than useful.

This is what the live data from my S62 looked like:

Interestingly, it had multiple coolant temp sensors along with EGT, but only one oil temp sensor. This is an interesting engine, as it had oil path diversion solenoids in its semi dry-sump system that redirected the oil pick-up circuit based on G-forces. I expect that even given the complexity this was ultimately cheaper than a true dry sump.

 

[NitroM3]

Of all the vehicles that I"ve owned that have had oil temperature gauges (and that's been a few) they've all read different oil temperatures depending on operating condition. Some of my most recent observations have been posted on here.

Good write and you actually supported some of what I said. Really we are on the same side I just write differently. Also I am sure you know that all this talk about oil temperature it takes a fraction of a second (engine used in racing generally run at extremes RPM) to cause black death on engine bearings no matter what the oil is and is generally related to a flash in oil temperature. I deal in fractional numbers not rounded up to the nearest ease for the eye to relate values.
You are also using ECU/ECM information for your supportive information as I do as well and all that is perfect for you and I but is different from what the average driver sees looking at the dash temperature gauge.

I have used and installed custom several DRY sump system over the years.

 

[OVERKILL]

Good write and you actually supported some of what I said. Really we are on the same side I just write differently. Also I am sure you know that all this talk about oil temperature it takes a fraction of a second (engine used in racing generally run at extremes RPM) to cause black death on engine bearings no matter what the oil is and is generally related to a flash in oil temperature. I deal in fractional numbers not rounded up to the nearest ease for the eye to relate values.
You are also using ECU/ECM information for your supportive information as I do as well and all that is perfect for you and I but is different from what the average driver sees looking at the dash temperature gauge.

I have used and installed custom several DRY sump system over the years.

Not familiar with "black death" in the context of bearing failure, can you expound on that one? I've never lost an engine in service, but I don't do a lot of racing so perhaps this just isn't something I've come across due to that fact. Most of my racing has been drag racing. A good friend of mine with a CasCar engine in his 2nd gen Camaro managed to over-rev and spin a rod bearing but I don't know somebody personally who has lost an engine due to lubricant failure, even though, IMHO some of them should have (think: crazy abuse with extended OCI's on total garbage oil).

Yes, I sense we are mostly on the same page, my point was simply in defence of the temp being provided on production vehicles being bulk sump temp, which makes sense in the context of why it is provided. The presence of oil/coolant heat exchangers also means that the range observed is going to be similar since coolant temp is typically regulated to the same range across marques.

Amusingly, my M5 (as did most M bimmers of the era) had an analog oil temp sensor on the bottom of the tach

But having access to the ECU information and being able to datalog it was of course much more useful in establishing and tracking trends.

 

[NitroM3]

Not familiar with "black death"

I've never lost an engine in service, but I don't do a lot of racing so perhaps this just isn't something I've come across due to that fact. Most of my racing has been drag racing. A good friend of mine with a CasCar engine in his 2nd gen Camaro managed to over-rev and spin a rod bearing but I don't know somebody personally who has lost an engine due to lubricant failure, even though, IMHO some of them should have (think: crazy abuse with extended OCI's on total garbage oil).

Yes, I sense we are mostly on the same page, my point was simply in defence of the temp being provided on production vehicles being bulk sump temp, which makes sense in the context of why it is provided. The presence of oil/coolant heat exchangers also means that the range observed is going to be similar since coolant temp is typically regulated to the same range across marques.
But having access to the ECU information and being able to datalog it was of course much more useful in establishing and tracking trends.

Complete loss of all oil to protect a bearing.
In NHRA I run/ran (retired now from professionally racing $$$ lol ) S/G 9.90 in a 68 Camaro. I could go through at times 3 engines a year @ about12-25k for a season or per year and that is if I stayed in 9.90 and not enter 8.90 class. In my Camaro I could have easily done 8.90's and have done exhibition runs even quicker but it costs much more in broken transmission at about 5-7k per transmission and as they say Speed Cost how quick do you want to go. LOL I had to maintain at least 15 events a year to keep my ranking. The good thing is I owned and operated my own Performance Engine Machine shop. I ran a attenuated adjustable sensor to shut the engine down should the oil temperature reach my chosen value. That value was calculated by observation of where IMO engine began to fail and also to keep the closet control on all operating temperature not solely the oil in order to maintain consistent runs.
Having the machine shop I got to see many customers destroyed engines in every fashion imaginable. I have also destroyed a few on my engine Dyno trying to make more power goodies. LOL So while many responses even form members that have the perfect oil specification information in the real world it is so much different because all those specification are based on consistencies of variables which is not as they say what happens in the real world.
The best way I can explain my personality is I am also a pilot..... we stress and constantly monitor all temperatures and even the smallest changes in temperature's. I am that way even when I am running up to get a bag of groceries. I dont run the engine rpm up until Iam in open loop and coolant 129.5F which is the temperatures 130F is open loop unfortunately the oil is slow and will not reach at least 160F for about 3-5 minutes and then both the coolant and oil will close to the same reading in most normal driving situations . Ya I did post all rounded up values. LOL This is because the ECU is coolant constant display and the oil temperature are analog on a gauge in my console.

 

[vavavroom]

I see 210-220F when cruising, rarely over 230 during street driving, higher when crushing it. No worries until 300F.

 

[NitroM3]

I see 210-220F when cruising, rarely over 230 during street driving, higher when crushing it. No worries until 300F.

2015 Mini Cooper S Roadster Convertible, fun car {your car auhhuh... I think you would "freak out" if you measure your turbo oil line.
I realize your baby TURBO would fit in the palm of my hand but it still cooks that motor oil when you get into boost even as little as 1psi. LOL

 

[vavavroom]

2015 Mini Cooper S Roadster Convertible, fun car {your car auhhuh... I think you would "freak out" if you measure your turbo oil line.
I realize your baby TURBO would fit in the palm of my hand but it still cooks that motor oil when you get into boost even as little as 1psi. LOL

I was actually not talking about the Mini. But yes, the turbo cooks the oil for sure.

 

[930.engineering]

I think you would "freak out" if you measure your turbo oil line.

That's why it's better there's no sensor. Even the pistons lack oil temp sensors.....

Seriously, I see no reason to drive yourself crazy, at least when your engine is stock.
All my engines remained entirely stock and they always will (as long as I own them).

.

 

[NitroM3]

That's why it's better there's no sensor. Even the pistons lack oil temp sensors.....

Seriously, I see no reason to drive yourself crazy, at least when your engine is stock.
All my engines remained entirely stock and they always will (as long as I own them).

.

hmm well that's not altogether accurate you can determine combustion temperatures which could estimate the temperatures of the cylinder walls, pistons and piston rings, valves etc. and for some of us depending of what the engine is used for is very critical.

As for leaving "ALL" your engine stock I find that hard to believe because this would also mean your only use OEM parts. And I am pretty sure about a few things that are not OEM you mention using on other threads?? LOL
Besides what fun is it not to improve things. But I understand, me on the other hand it is what I do for fun and as a business in the automotive industry. And I ain't talking about servicing vehicle's either LOL

 

[NitroM3]

I was actually not talking about the Mini. But yes, the turbo cooks the oil for sure.

So you can pick and choose what best supports your information? OK!

 

[vavavroom]

So you can pick and choose what best supports your information? OK!

You correlated the information I gave to a random vehicle you picked from my vehicle list. I haven't tracked the Mini so I can't make a statement regarding oil temperature at prolonged high speed and high RPM. I also haven't towed a boat with it. So far, with city, highway, and freeway driving, the Mini's oil temps are comparable to most cars I have owned.

 

[930.engineering]

How come you all post rounded number? Analog gauges sure because they are faced with aprox. values that you have to guess in between the labeled numbers but ECU/ECM information and digital gauges they all report like 197.5 or 217.8 ext., (unless ECU programed scaled for easy reference on the dash gauged) LOL This is like when you take your foot off the throttle and you only see 99.99 MPG max on the instant MPG indicator when in reality it is much different and higher depending on the injector operation and program in the ECU . But here again the OBDII is different and actual then the dash reading for driver convenience.

So now it's sufficient to estimate temperatures?

hmm well that's not altogether accurate you can determine combustion temperatures which could estimate the temperatures of the cylinder walls, pistons and piston rings, valves etc. and for some of us depending of what the engine is used for is very critical.

As for leaving "ALL" your engine stock I find that hard to believe because this would also mean your only use OEM parts. And I am pretty sure about a few things that are not OEM you mention using on other threads??

Is trying several engine and gear oils regarded as modding the car?

Granted, I modded suspensions, brakes, aerodynamics, wheels and tires on many of my former cars (because I didn't found themstock to suit my needs and it's part of my profession), however I never ever touched the engine. That's because I like to (only) do things I do understand and I'm not an engine guy. And that's probably also because I am an engineer and I conjecture the added load and strain on the internals. Not to forget the gearbox in my 911 isn't exactly what the car came from factory with, however I still keep the factory 4-speed on spare. Doing more to this classic would be a sacrilege. Doing more to the GTI isn't required as it's almost just as perfect as it gets. The Mini? That's the one most predestined for modding. It's far from being perfect and certainly desires a better suspension. And true gauges for oil temp at least, which it sadly lacks (it even lacks a sensor, OBD just reads water temp and estimates oil temp).

Besides what fun is it not to improve things. But I understand, me on the other hand it is what I do for fun and as a business in the automotive industry. And I ain't talking about servicing vehicle's either LOL

In my view more power isn't necessarily an improvement. For example very most aftermaket software will affect longevity and reliability. You can't add 100 or even 150 ft-lbs to a GTI and expect the clutch to last the same. I bought a GTI Performance for a reason. If I'd wanted more power, I'd have gone with a GTI Clubsport or GTI TCR or something. I just don't need it, it's got plenty of power to break traction even on Michelin PSS and with the LSD. More power, even more traction issues.

.

 

[NitroM3]

LOL you equate my response as if everything is about engine power improvements.
As for power improvements you are using a single POSIBLE SCENERO EXAMPLE? lol
You do realize there is a % increase known in the performance world and used to increase a safe level of engine power to most all commonly known factory gasoline stock OEM engines right ?
I guess I had better add that I like you , engineer and design, suspension, chassis and brake system and components. As one of my businesses
Hey you and the other members and maybe some more coming into this conversation can have fun. I will take it off my watch list because I already can see where this will go.
Thank for reading what I had to say!

 

[edyvw]

Complete loss of all oil to protect a bearing.
In NHRA I run/ran (retired now from professionally racing $$$ lol ) S/G 9.90 in a 68 Camaro. I could go through at times 3 engines a year @ about12-25k for a season or per year and that is if I stayed in 9.90 and not enter 8.90 class. In my Camaro I could have easily done 8.90's and have done exhibition runs even quicker but it costs much more in broken transmission at about 5-7k per transmission and as they say Speed Cost how quick do you want to go. LOL I had to maintain at least 15 events a year to keep my ranking. The good thing is I owned and operated my own Performance Engine Machine shop. I ran a attenuated adjustable sensor to shut the engine down should the oil temperature reach my chosen value. That value was calculated by observation of where IMO engine began to fail and also to keep the closet control on all operating temperature not solely the oil in order to maintain consistent runs.
Having the machine shop I got to see many customers destroyed engines in every fashion imaginable. I have also destroyed a few on my engine Dyno trying to make more power goodies. LOL So while many responses even form members that have the perfect oil specification information in the real world it is so much different because all those specification are based on consistencies of variables which is not as they say what happens in the real world.
The best way I can explain my personality is I am also a pilot..... we stress and constantly monitor all temperatures and even the smallest changes in temperature's. I am that way even when I am running up to get a bag of groceries. I dont run the engine rpm up until Iam in open loop and coolant 129.5F which is the temperatures 130F is open loop unfortunately the oil is slow and will not reach at least 160F for about 3-5 minutes and then both the coolant and oil will close to the same reading in most normal driving situations . Ya I did post all rounded up values. LOL This is because the ECU is coolant constant display and the oil temperature are analog on a gauge in my console.

Happens on BMW N54/55 and to less extent N51/52/53 engines. When one turning hard to the left (this is possible only on track) if G forces are very high, the engine can stay without lubrication. There is a whole industry of offering baffle oil pans, accu sumps etc. but it seems only M version oil sump which can withstand 1.7G is the solution.

 

[Jetronic]

What is so special about that M sump?

 

[Jetronic]

Happens on BMW N54/55 and to less extent N51/52/53 engines. When one turning hard to the left (this is possible only on track) if G forces are very high, the engine can stay without lubrication. There is a whole industry of offering baffle oil pans, accu sumps etc. but it seems only M version oil sump which can withstand 1.7G is the solution.

What is so special about that M sump? Most of those high G sumps only protect for a few seconds as the oil isn't guaranteed to return to the sump with sustained high G (long sweepers for instance).

Also, around what G is the regular sump becoming a problem

 

[edyvw]

What is so special about that M sump? Most of those high G sumps only protect for a few seconds as the oil isn't guaranteed to return to the sump with sustained high G (long sweepers for instance).

Also, around what G is the regular sump becoming a problem

It seems consensus is around 1.2g on regular sump.
I really didn’t go into details what is difference between M and regular, but M can take more G load and doesn’t have these issues whatsoever.