Oil Coolers and Over cooling

phunk

The oil temperature sensor is in the pressure channels just off the oil filter. It is measuring oil temp of the oil that is entering the pressurized lubrication passages in the engine.

The only thing I cannot answer on the VHR specifically is if it is before or after the oil filter, because I have not taken the upper pan off and followed the oil passages in the upper pan casting. If it is before the oil filter, meaning just inline after the pump, then we are not able to see the immediate effects of the oil after leaving our aftermarket coolers. If it is after the oil filter, then we are seeing the immediate effects of our added coolers. I have an extra VHR engine sitting in my garage to use for my built engine project, sometime in the next few weeks when I take it apart to begin the build I can report back the answer to this.

But regardless of all that, the oil temperature sensor is definitely in the pressure channels after the pump.

Also, engines do not really have much of a return path for oil. The only passages for it are positioned near the cylinder head studs so that the oil can leave the cylinder heads and just drip back into the open crankcase down the sides. The upper oil pan itself, does not have any oil return passages.

Refer to service manual page LU-7. There you will read it instructing you to test engine oil pressure by removing the oil temp sensor and installing the nissan oil pressure test gauge hose. This is the only evidence I have at the moment of what I am saying... but it is clear evidence.

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ZForce

Hey guys, not sure if this will help, prior to the start of this thread I have read several other related oil cooler threads and combined several discussions into one post here: fall weather. the Z is staying at 190 degrees with,

I have re-posted it here. If its of no help and only boggles this discussion I will delete it. Let me know. Btw this is a great thread, subscribed.


Re-post:


Something to add to this thread (even if it's only for my own reference later when my memory has gone) since I have been reading through a lot forum threads lately on oil coolers, low oil temps, mocal thermostatic sandwich plates opening temp, the general oil temp we want to see coming OUT of the engine block, and block off plates. There a numbers of good threads on the topics. I have compiled the posts pertaining to the above mentioned topics and included the links to the threads for reference and further reading.

Here are some comments by Dustin from Z1 Motorsports who sells oil cooler kits.

Nissan Motorsports Oil Cooler vs. Stillen Oil Cooler


Nissan Motorsports Oil Cooler vs. Stillen Oil Cooler


Z1 Motorsports 370Z Oil Cooler Kit





Another good thread on the complete explanation on how the Mocal Thermostatic Sandwich Plate Operates:


Introducing the Z1 Motorsports 370Z Oil Cooler Kit *Customizable*


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cdoxp800

Well done ZForce. I was looking for that thread.

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2011 Brilliant Silver NISMO 370z. #: 0046.
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MattP725

I think your wording is off... this isn't oil coming back to the pan, it is oil leaving the pan to the block.

All in all I wouldn't see this being a major issue anyhow... once the oil is at operating temperature, the oil in the pan/block/cooler are eventually going to meet some sort of equilibrium. Even without a cooler you have to beat on it pretty heavily to get an immediate and sharp climb in oil temperature and that is generally only 10-20 degrees.

ZForce

Glad it was helpful

cdoxp800

Opps, correct. Been a little sick.

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2011 Brilliant Silver NISMO 370z. #: 0046.
PPE LTH | MillSpec Cats | F.I Exhaust | Akuma Intakes | Rotora 6/4 Brakes

DLSTR

The cover in the DIY by Speafish is so easy its not even funny. I did mine in 15 mins. Do it and be done with it. My temps are 180-200 now. Im in Germany and with it cooling off before the cover was on, I was seeing 160 for the oil temps.

ImportConvert

You do realize the limp mode serves a purpose, yes? It took time to program, and time means money, and no corporation spends money without profit in mind, and what profit is there to be made with a limp mode unless warranty work were avoided by having it...

ZForce

Glad the DIY link helped. I plan on installing my 25r oil cooler in the next few weeks and will testig out the correct plate coverage for ambient temps in the mid 30's plus. Will be starting with covering 80% of the cooler and go from there. Ideal dash gauge temps will be 170-190 with actual temps being 190-210.

Super Tanooki

I know I'm digging up an old thread but since, you know, "search the forum first..."

Thanks a lot ZForce and Dustin@Z1 for the info RE: post-OC temp readings. I used to feel a HUGE drop in power at about 225* (anyone else notice this?) before I got the OC. The OC install dropped my average temps LOADS so I thought the problem was over, but now I feel the power drop at around 205. It was baffling me for the longest time but that MUST mean the in-engine oil temps are basically about 20* hotter than the gauge says.

I just wish the car wouldn't pull so much power at 225*. I mean, it's terrible, even flooring it in first gear does near nothing until 4000rpm. :-/ Do you all get this lag at those temps?

Oh, on a side note, has anyone noticed turning on their AC ironically brings engine temps down about 10*? It's pretty consistent. I'm in Vegas, and I'd usually just bear the heat, but I actually HAVE to turn on AC just to kick in the fans to help cool my engine when it's lagging like hell.

Dustin@Z1

No problem sir!

The drop in temp may be because the Aux fans kick may automatically kick on when the A/C is cycled on. I have honestly never paid any attenion to the 370Z and how this behaves. But I know most old school vehicles did this.

SS_Firehawk

I would look at the IAT's that are coming in as well. Being in Vegas, the air is thinner, the pressure is lower, and it's much hotter. Did you notice it dropping power at 205 in the winter? I'm fairly certain the motor is pulling timing because it's sucking in air that's as hot as a hair dryer. An oil cooler does help maintain power, it's definitely not the cure all for maintaining it consistently through weather changes.

This is just an educated guess so please don't take this as word of God.

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DIGItonium

While we're on the topic of oil coolers, I have a stupid question. Are you guys using more than 5 quarts of oil? I might be 1 quart short (~ 10mm from H mark). I'm at 1,300 miles now since the last change.

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roy'sz

I use exactly 5qts of oil and it puts me right at the high dot on my dipstick, and I too have a little bit of oil consumption. The service manager told me that it was normal

wstar

The behavior varies by vehicle design, but I too have definitely observed that a Z with normal ECU settings runs colder with the AC on. This seems counter-intuitive at first since the AC should be (a) adding engine load and (b) adding a little more heat back into the radiator via the condenser (the heat extracted from the hot air to make it blow cold). However, as noted by Dustin above, it's the fact that the ECU turns on the electric radiator fan(s) more often that makes up the difference and then some, due to increased airflow through the radiator (esp at lower speeds).

UpRev can now control this behavior: there are independent settings for AC-on vs AC-off which control fan duty cycle -vs- water temps. Aside from turning them on earlier in general, you can set the AC-on settings the same as AC-off and then you don't have to turn on the AC just to get the fans going.

Thread here: Fan Control now available!

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