# Engine Oil level at Minimum



## Snipe656 (Oct 22, 2009)

Why an oil temp over water temp preferece? This is the first car I ever owned that lacked a water temp gauge. The water temp gauge is one of the things I always pay attention to, so been a hard adjustment for me not to have one. I only have had an oil temp gauge once and that was in my ok'd race car and put it more to fill a gauge pod than anything else.


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## Flyingman (Sep 13, 2009)

OK, here is what I got this morning.

Start up ambient was 75 Deg F. A/C weather for sure!

Within first 30-45 seconds it reached 100 Deg F.

My drive is about two blocks to a 40mph boulevard with some 4 red lights till I reach the on ramp for I-75.

Temp quickly rose to 185 by the time I reached the last light before the on ramp, approx 4miles or 5-6 minutes. This traveling at 40mph.

As I accelerated onto the I-75 ramp it reached about 190-192 then settled in at about 194 with an occasional spike at 196. The 194 was reaching speeds of 100 but basically about 80-85mph. The 196 was more in bumper to bumper traffic and as I pulled into the parking garage.

So at least I am satisfied that my 4 mile drive to the interstate is ample enough time and distance to properly warm up the cooling water.

I'll try to get a few photos to show, and now I will start to focus in on the % Engine Load and what that means.:dunno:


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## HIREN (Jul 14, 2006)

FYI, you can use the OBC secret service menu to view the coolant temp instead of buying an OBD II Scanner.

http://e90.wetpaint.com/page/BC+hidden+menus?t=anon

It's a little tedious, but does the job.


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## magbarn (Jan 28, 2003)

Snipe656 said:


> Why an oil temp over water temp preferece? This is the first car I ever owned that lacked a water temp gauge. The water temp gauge is one of the things I always pay attention to, so been a hard adjustment for me not to have one. I only have had an oil temp gauge once and that was in my ok'd race car and put it more to fill a gauge pod than anything else.


Oil temp is the closest to the true temp of the engine block/turbos and it will usually lag the coolant temp by a few miles.


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## Snipe656 (Oct 22, 2009)

I can understand for the turbos but why would a lag be there for the block? Isn't the coolant temp sensor itself in the intake or block and measuing the fluid's temp there?


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## magbarn (Jan 28, 2003)

Snipe656 said:


> I can understand for the turbos but why would a lag be there for the block? Isn't the coolant temp sensor itself in the intake or block and measuing the fluid's temp there?


From the 335i I drove that had a scangauge, the coolant hit 190+ much sooner than the oil temp gauge reaching the 'middle' (which is 240F)


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## Snipe656 (Oct 22, 2009)

But both readings are based off the fluids so I am not sure either is really a more reliable method of actual block temps. The water temp sensor should read higher quicker because of the t-stat and when it opens/closes. From the standpoint of wanting to be able to detect a problem via increased temps it seems like either would work and be no better than the other.


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## Snipe656 (Oct 22, 2009)

BTW, in my old "race" car that had both gauges I do not recall ever quickly detecting blown headgasket problems via the oil temp gauge but I do remember seeing it via the water temp gauge. It would depend on how the gaskets blew and lord knows I had many variants of that. But one of the common ones I would see would involve a spike in water temps then the pressure would get released but the water temp would still be high. I could stop the car, top off my radiator at that point and still drive it on the street. I have caught things via oil pressure gauges as well, but they were not really heat related. I guess in my world I just prefer to first have a water temp gauge and then an oil pressure gauge and after that I am open to whatever else can be crammed in a display.


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## F32Fleet (Jul 14, 2010)

bimmermanNJ said:


> I got my first oil change and now I get a message periodically that the engine oil level is at minimum. I checked the oil level the first time this happened - which was immediately after I got home from the dealer after my first oil change. My oil level is between min and max level. I guess a faulty oil sensor? Anyone else with this issue and did you replace the oil sensor?


Never had problem, but are you sure of the oil level? The diesels take 8 or 8.2 quarts unlike the 335i which takes ~7. They may have just underfilled.


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## Flyingman (Sep 13, 2009)

HIREN said:


> FYI, you can use the OBC secret service menu to view the coolant temp instead of buying an OBD II Scanner.
> 
> http://e90.wetpaint.com/page/BC+hidden+menus?t=anon
> 
> It's a little tedious, but does the job.


Wow, got a headache reading through all of that!

I assume you have to be parked when you do this, so what is the point?:dunno:

For $99 bucks (GPS not included) I get the attached user's selectable gauge display on my GPS plus error code display and resetability.:thumbup:


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## Penguin (Aug 31, 2003)

Snipe656 said:


> Why an oil temp over water temp preferece? This is the first car I ever owned that lacked a water temp gauge. The water temp gauge is one of the things I always pay attention to, so been a hard adjustment for me not to have one. I only have had an oil temp gauge once and that was in my ok'd race car and put it more to fill a gauge pod than anything else.


There is a third alternative... my Ford Focus has a head temperature gauge instead of oil or coolant temperature.


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## Snipe656 (Oct 22, 2009)

Penguin said:


> There is a third alternative... my Ford Focus has a head temperature gauge instead of oil or coolant temperature.


That is a new one to me but I was thinking earlier I guess it really does not matter where the temp source is just so long as I can have a gauge to show engine temps. I just like it because in the past on different cars I could detect when something was going wrong. It just so happens that all of them(I think at least) got their temp source from coolant readings.

I wonder how the head temp works, if it just reads the temp of the metal itself or a fluid or even air within.


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## Penguin (Aug 31, 2003)

Snipe656 said:


> I wonder how the head temp works, if it just reads the temp of the metal itself or a fluid or even air within.


The metal.

I think they use it for engine control purposes, such as cold start enrichment, and feel the temp of the head is a more direct measurement. It may allow them to more quickly reduce the enrichment, helping in the EPA test cycle. The Focus also has an interesting "feature" which might also make the head temp a better parameter to monitor. If the engine is overheating badly, it will switch the engine from using all 4 cylinders to a "limp mode" where it only uses two cylinders to reduce heat generation. The computer constantly switches which two cylinders are used when in this mode to minimize heat damage to the cylinders. Of course, if it get too hot, it completely shuts the engine down, but the limp mode should give some time to get to a safe place to stop.

Rather ingenious, IMHO.


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## HIREN (Jul 14, 2006)

Flyingman said:


> Wow, got a headache reading through all of that!
> 
> I assume you have to be parked when you do this, so what is the point?:dunno:
> 
> For $99 bucks (GPS not included) I get the attached user's selectable gauge display on my GPS plus error code display and resetability.:thumbup:


I've done it while driving, but it's easiest to do it while stopped. Once it's set, the OBC display stays that way until you turn the car off or hold down the trip reset button for 10 seconds. This ensures you can monitor the coolant temp or any other parameter in digital real time during your trip.

Your setup is easier of course, the price is not bad either. I have a BT cable for reviewing/clearing codes, though it requires a laptop.


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## autoJeff (Oct 1, 2009)

I used the BC coolant temp feature last time I did a driving school at the track. Was curious how hot it would get and how long it took to cool down. Here's some data in degrees C. 

82-86 normal op range street
82-83 at a stop light
85-86 a minute past stop light, steady state
89-91 seems to indicate DPF regen. Turn off motor and a fan runs for 12 minutes.
98 highest I noticed coming off track after 1/2 lap of cool down. I never remembered to look between checkered flag and exiting track 1/2 lap later. 

Driving around the paddock the temp quickly (IMO) came back down to normal range. Then down to 83-85 while idling while chatting with my instructor. 

The engine/exhaust sound definitely changes as things warm up. I try not to let RPM go high until coolant temp is at or near 83. I'd like ability to also see oil temp. Actually, would be nice to see both on idrive screen. Don't understand why that's not implemented. First manufacturer to do that will get bonus "coolness" sales.


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