how cold is too cold for oil temps?

atropine · 11-30-2010, 07:44 AM

so i just installed an oil cooler. this morning it is 38F outside. just finished my 50 mile freeway commute, on cruise at 82 mph, turning a little over 3k rpms, oil temp hovered right at 145. running factory ester oil. idling in the parking lot now im at a little over 150. too cold?

Jeffblue · 11-30-2010, 08:05 AM

not really sure, i'm curious about this as well

spearfish25 · 11-30-2010, 08:13 AM

Too cold. You want the engine to heat up to about 180 minimum, and the quicker the better.

Simple solution:
DIY: Oil Cooler Cover

flashburn · 11-30-2010, 08:32 AM

I think we need a sticky on this. Here is what Dustin@Z1 had to say about the oil temp's I was seeing (about 160 after warm up):

Quote:

Originally Posted by Dustin@Z1

No worries. This is perfectly normal. There is a slight flaw in the VQ37VHR's design that we have discovered. Like I have mentioned in the past, over cooling the engine oil is just as detrimental as over heating it. The general oil temp range you want to see on a properly installed oil temp gauge is between 190 ~ 210 ideally.

This engine oil temp is what you want to see COMING OUT from the motor. In the case of the 370z and any add-on oil cooler, you are actually getting a false reading. Since the factory temp gauge reads engine oil as it exits the Oil Filter, you are actually reading the oil temp coming directly from the oil cooler. The flow pattern for engine oil on a 370z is as follows:

Pick Up Tube --> Oil Pump --> Oil Filter IN --> Oil Filter Out --> Oil Cooler --> Engine Block (Temp and Pressure gauges are located in this galley)

The temp you are reading is actually what is going back INTO the engine (which is perfect). By the time it cycles thru the engine, you can expect to see engine temps in 200 degree range.

As for the thermostatic sandwich plate, it will bypass roughly 80% of the oil back into the engine when too cold. It will still flow ~ 20% thru the oil cooler (preventing air pockets from forming).

To get a TRUE Oil Temp reading, you would need to install an inline oil temp gauge coming out from the Thermostatic Sandwich plate before the oil cooler.

I hope that this answers some questions and relieves some stress! If you have an questions, definitly give me a shout.

That said, 145 is pretty low, you should probably make a metal shroud of some sort to cover the cooler in the cooler months, unless you are on a track of course. Although if you are seeing 145, in reality it is closer to 160-170, but yeah, that's still low.

spearfish25 · 11-30-2010, 08:39 AM

I could swear the temp and pressure sensors are at the oil pan level. I see them every time I'm under the car. The gauge reading should be real close to what's sitting in the oil pan after circulation, not what's coming from the cooler.

*Confirmed. See attached image from service manual.

shumby · 11-30-2010, 08:51 AM

you can install a temp bbypass valve on your oil cooler. It will by pass the cooler until a certin set point is reached. GTM offers this solution. I have it on my car as I can see down to -56C in the winter

atropine · 11-30-2010, 12:31 PM

Thanks guys. I will look at making a cover for the cooler tomorrow. Looking at that diagram, it looks like the oil temp sensor does sit just inside the block from the oil filter, above the oil pan. If the oil level does not sit up that high above the pan, I guess I could see how Dustin @ Z1 would say that the returning oil temp is different than the oil lying down in the pan. I just don't know what the natural resting oil level is in the pan.

Mike · 11-30-2010, 12:43 PM

Quote:

Originally Posted by spearfish25

I could swear the temp and pressure sensors are at the oil pan level. I see them every time I'm under the car. The gauge reading should be real close to what's sitting in the oil pan after circulation, not what's coming from the cooler.

*Confirmed. See attached image from service manual.

doesn't it flow from the cooler into the pan?

flashburn · 11-30-2010, 12:45 PM

Quote:

Originally Posted by Mike

doesn't it flow from the cooler into the pan?

Yeah, I think that was what Dustin was saying basically.

It makes sense that it is reading off, especially since I have zero issues getting up to 160, and then once it gets there, if I'm just doing normal highway driving (even in 85 degree temps) it will stick there, even though I have a 180 degree thermostatic plate. I know the plate will always flow some oil through, but it won't completely open until 180 degrees.

wheee! · 11-30-2010, 12:50 PM

Well us Canadians are screwed then....

hmmm... does Stillen make an oil heater?

-30 degrees Celsius here lately. That's like a bazillion below fahrenheit....

spearfish25 · 11-30-2010, 01:17 PM

Quote:

Originally Posted by Mike

doesn't it flow from the cooler into the pan?

Yeah, via the engine block!

Oil cooler(colder oil)-->engine block(warmer oil)-->pan where sensors are, thus reading the warmer oil

Dustin's description follows this reasoning, but the sensors are in the oil pan...not the engine block. Thus, the sensors read the sump oil temperature where the oil collects after circulating through the motor. The outflow from the cooler passes through the engine block (where it gets heated), and that oil doesn't hit the sensors until it collects in the pan again. So it would reason that the sensor temp should reflect the oil temp in the block and not the cooler outflow.

Take a look at the picture I've attached. The temp sensors are essentially where the arrow indicating 'oil pan' point. Our cooler plumbs in-line to the right of the oil filter in that picture (courtesy of the sandwich plate). So oil from the sump goes through the filter, through our cooler, and then through the engine.

Simply put, Dustin suggests the sensors are in the area labeled 'main oil gallery' and they're actually in the pan.

spearfish25 · 11-30-2010, 01:41 PM

Quote:

Originally Posted by wheee!

-30 degrees Celsius here lately. That's like a bazillion below fahrenheit....

Ha! Or just -22F.

flashburn · 11-30-2010, 01:45 PM

Interesting spearfish. Hopefully Dustin can chime in, in case there is a misunderstanding of some sort, but your explanation sounds good too.

John@Z1 · 11-30-2010, 05:08 PM

190-220 is about the best for oil temps for optimum performance. Spencer and Dustin has something in the works for you all.

blackbird · 12-01-2010, 05:00 PM

John:
I'm running like 160 when temperatures is in the 30's. OK or no?

11-30-2010, 07:44 AM	#1 (permalink)
atropine Base Member Join Date: Aug 2010 Location: Logandale, NV Posts: 39 Drives: 09 6MT Sport/Tour/Nv Rep Power: 15	how cold is too cold for oil temps? so i just installed an oil cooler. this morning it is 38F outside. just finished my 50 mile freeway commute, on cruise at 82 mph, turning a little over 3k rpms, oil temp hovered right at 145. running factory ester oil. idling in the parking lot now im at a little over 150. too cold?

11-30-2010, 08:13 AM	#3 (permalink)
spearfish25 A True Z Fanatic Join Date: Mar 2009 Location: Naples, FL Posts: 4,117 Drives: to work Rep Power: 1856	Too cold. You want the engine to heat up to about 180 minimum, and the quicker the better. Simple solution: DIY: Oil Cooler Cover __________________ 2013 Cadillac V-Wagon, RIP Z

11-30-2010, 08:51 AM	#6 (permalink)
shumby Captin Canuck Join Date: Dec 2008 Location: with your mom Age: 44 Posts: 6,288 Drives: your sister Rep Power: 236	you can install a temp bbypass valve on your oil cooler. It will by pass the cooler until a certin set point is reached. GTM offers this solution. I have it on my car as I can see down to -56C in the winter Red Voodoo likes this. __________________ Originally Posted by SAM@GTM Engine detonation is not normal and it should never never happen, and whoever told that need to do something else for living . Sam

11-30-2010, 12:50 PM	#10 (permalink)
wheee! A True Z Fanatic Join Date: Sep 2009 Location: Mod Capital of Canada Age: 57 Posts: 7,354 Drives: cars. lots of cars. Rep Power: 40182	Well us Canadians are screwed then.... hmmm... does Stillen make an oil heater? -30 degrees Celsius here lately. That's like a bazillion below fahrenheit.... __________________ H&R / Stillen / Berk / HKS / Swift / Michelin / UpRev / SPC / Amuse Rep / Seibon / Fringe XVO / TWM / more... My Journal

11-30-2010, 01:45 PM	#13 (permalink)
flashburn A True Z Fanatic Join Date: May 2009 Location: Central Florida Posts: 1,884 Drives: '12 Corvette GS 6M Rep Power: 19	Interesting spearfish. Hopefully Dustin can chime in, in case there is a misunderstanding of some sort, but your explanation sounds good too. __________________ Current Ride: 2012 Chevrolet Corvette Grand Sport Centennial Edition Carbon Flash 6M Previous Ride: 2009 Nissan 370Z Sport Platinum Graphite 7AT

11-30-2010, 08:05 AM	#2 (permalink)
Jeffblue A True Z Fanatic Join Date: Dec 2009 Location: NY Age: 36 Posts: 9,192 Drives: Z32TT & 335xi Coupe Rep Power: 37	not really sure, i'm curious about this as well

11-30-2010, 12:31 PM	#7 (permalink)
atropine Base Member Join Date: Aug 2010 Location: Logandale, NV Posts: 39 Drives: 09 6MT Sport/Tour/Nv Rep Power: 15	Thanks guys. I will look at making a cover for the cooler tomorrow. Looking at that diagram, it looks like the oil temp sensor does sit just inside the block from the oil filter, above the oil pan. If the oil level does not sit up that high above the pan, I guess I could see how Dustin @ Z1 would say that the returning oil temp is different than the oil lying down in the pan. I just don't know what the natural resting oil level is in the pan.

11-30-2010, 05:08 PM	#14 (permalink)
John@Z1 The370Z.com Sponsor Join Date: Nov 2008 Location: GA Posts: 1,589 Drives: Turbos Rep Power: 20	190-220 is about the best for oil temps for optimum performance. Spencer and Dustin has something in the works for you all. __________________ Z1 Motorsports will beat any advertised price on Nissan OEM Parts! 770-838-7777 ext 311 AIM: JohnatZ1 email: John@Z1motorsports.com

12-01-2010, 05:00 PM	#15 (permalink)
blackbird Base Member Join Date: May 2009 Location: Nashua NH Posts: 179 Drives: 09 370Z BLk GTM TT Rep Power: 16	John: I'm running like 160 when temperatures is in the 30's. OK or no?

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