Nissan 370Z Forum - how cold is too cold for oil temps?

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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?

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

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

Simple solution:
http://www.the370z.com/diy-section-d...ler-cover.html

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.

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.

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

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.

Quote:

Originally Posted by spearfish25 (Post 828278)

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

Quote:

Originally Posted by Mike (Post 828499)

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.

Well us Canadians are screwed then.... :eek:

hmmm... does Stillen make an oil heater? :icon17:

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

Quote:

Originally Posted by Mike (Post 828499)

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.

Quote:

Originally Posted by wheee! (Post 828506)

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

Ha! Or just -22F.

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

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

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