Nissan 370Z Forum - Oil Coolers and Over cooling

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- - Oil Coolers and Over cooling (http://www.the370z.com/engine-drivetrain/46971-oil-coolers-over-cooling.html)

Quote:

Originally Posted by cdoxp800 (Post 1457610)

I never said it was "on" the return line from the oil cooler. I said

The FACTORY (OEM) sensor reads this Temp on the block on the return path to the oil pan. As seen in the attached Pic. Any more questions?

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.

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: http://www.the370z.com/1435977-post21.html

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.

http://www.the370z.com/815172-post115.html

Quote:

Originally Posted by flashburn (Post 815172)

........... here is what Dustin@Z1 had to say about it when I asked him about the 160-ish temperatures I was seeing:

Quote:

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.

http://www.the370z.com/engine-drivet...tml#post815915

Quote:

Originally Posted by christian370z (Post 815915)

How far off is the factory oil temperature gauge? Is it reading low by roughly 20 degrees then?

Quote:

Originally Posted by daisuke149 (Post 815919)

from what i understand, theres no set difference. depends on the ambient air and the size of the cooler/speeds etc.

Quote:

Originally Posted by flashburn (Post 815929)

Yeah, that's my understanding as well, but 20 degrees might be a decent assumption. You can really tell in the case of "low temps", because if you have a thermostatic plate, you will see it get up to around 160-ish easily, and then usually stick around there unless you get stuck in traffic or are driving aggressively. Since it makes it up to around that temperature and sticks there, it seems like the thermostatic plate must be completely opened so it should be actually around 180 degrees. Or at least that's my logic behind it.

Maybe Dustin can chime in and give us a better idea. We really should make it a separate thread and sticky it.

http://www.the370z.com/drivetrain-en...ml#post1418647

Quote:

Originally Posted by Dustin@Z1 (Post 1418647)

CRWallace,
I appreciate your input on this, but keep in mind. The factory temp sensor that displays on the dash board is post-cooler. You are reading the oil cooler at its coolest temp where the oil re-enters the block. The oil is MUCH hotter once it cycles thru the engine and returns back out to the core.

I do agree with you and we have suggested this in the past to many of our customers and forum members here on the370z. Owners of Z/G's living in cooler climates or in the winter with ANY oil cooler should consider blocking off the front of the core during the cooler times of the year. This method is used widely by racing teams to further regulate oil temps.

Race teams will block off individual rows of the oil coolers during test and tune to "fine tune" oil temps depending on the track conditions, humidity and driving style. :tiphat:

Quote:

Originally Posted by adampetrasek (Post 1431356)

Is there a thermostatic plate that opens around 200 or 210? That seams like it might make a bit of difference for the temps entering the block?

Quote:

Originally Posted by Dustin@Z1 (Post 1432674)

Mocal does make a higher temp thermostat, but it is a remote mount style. This is a completely different setup when compared to the standard thermostatic sandwich plate that we currently use.

The current opening temp of the thermostatic sandwich plate we sell is 180* degrees F. This means, at 180* the bypass valve fully closes and directs 100% of the oil into the oil cooler core.

To build a custom Remote mount thermostatic sandwich plate with a higher temp. thermostat, it would increase the base kit price atelast $100 if not more. This is due to the fact that there would be double the total amount of fittings, 4 lines instead of 2, the requirement of a custom mounting bracket for the thermostat and a slight revision to the instruction manual.

I have had customer's express interest in the kit before, and would be willing develop it. We simply did not go this route due to to the added complexity and cost, which would have priced well out of the range of comparable kits. We wanted to make sure that we are competitive in every aspect....inlcuding price.

If you are a DIY type person, I can source the parts necessary to convert your existing -10 AN lines to accept the Remote Mount Thermostat. The catch will be the fact that you will need to cut your existing lines into two pieces, install new fittings and mount the thermostat. The sounds somewhat easy in writing, but assembling SS lines can be a pain in the neck!

Quote:

Originally Posted by ZForce (Post 1423176)

Does Z1 sell a core block off plate? If not then are there any photos floating around of a mock up block off plate on how to fab one?

Quote:

Originally Posted by John@Z1 (Post 1426496)

We don't have one just yet but I'm sure there is a DIY somewhere on this forum.

Quote:

Originally Posted by ZForce (Post 1435896)

Here are a couple, pretty much the same with additional mods and more in detail on the second link.

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

http://www.the370z.com/diy-section-d...off-plate.html

.

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

http://www.the370z.com/drivetrain-en...tml#post990449

.

Well done ZForce. I was looking for that thread. :tiphat:

Quote:

Originally Posted by cdoxp800 (Post 1457610)

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.

Quote:

Originally Posted by cdoxp800 (Post 1458696)

Well done ZForce. I was looking for that thread. :tiphat:

Glad it was helpful :tup:

Quote:

Originally Posted by MattP725 (Post 1458724)

Opps, correct. Been a little sick.

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.

Quote:

Originally Posted by Rooskey (Post 1457860)

Yea. Do you have an oil flow chart of the previous pick you posted. I already have a way to override the limp mode with the computer. The reason I ask is cause I have never heard of such a major problem on a car, and also have never heard of someone trashing a motor because of this situation. Unless someone proves otherwise I think this oil temp thing is nothing more than having a stupid guage on the dash. IF anyone has trashed an engine due to this please chime in. Thanks... (I know there are alot of debates on this subject and im not trying to start crap. Im just looking for facts on the situation)

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...

Quote:

Originally Posted by DLSTR (Post 1467757)

The cover in the DIY by Spearfish 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.

Glad the DIY link helped. :tup: 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.

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.

Quote:

Originally Posted by Super Tanooki (Post 1740233)

:tiphat: No problem sir!

Quote:

Originally Posted by Super Tanooki (Post 1740233)

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.

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.

Quote:

Originally Posted by Super Tanooki (Post 1740233)

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.

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.

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

Quote:

Originally Posted by Dustin@Z1 (Post 1742488)

:tiphat: 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.

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: http://www.the370z.com/tuning/51935-...available.html