2JZGE-T temperature control issues

veedubin

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So I got to take my swap for it's first official "road trip" on Sunday. I noticed that the coolant temp was a bit higher than they were on the 7M. at idle it will stay right at ~190*. I'm using an autometer procomp electric gauge and it's just past the 180* (a touch over halfway) That I'm ok with, it's the temps while driving that sort of worry me. I took the highway (speed about 75mph) for about 10 miles, in that time, the temp gauge creeped up to about 210* and stayed there. Once I arrived at church the car was shut off for about 2 hours. I restarted it and drove the same way home. Temps crept just past 210* I do not feel this is normal behavior for this car, or am I wrong. AFR's were ranging from 13.5 to 11.5 while driving.


Important info:
Gauge autometer procomp ultra light electric gauge
4337_d.jpg
http://autometer.com/cat_gaugedetail.aspx?gid=3113&sid=11
Probe installed into water neck from head to upper rad hose.
Cooling fan is 7MGTE fan clutch and blade (yes It works on a 2J water pump)
Factory 7MGTE rad.
I have heat - lots of heat - from heater system
Radiator and heater core were flushed and pressure checked during swap
No leaks, and coolant is full in both radiator and overflow bottle.
Nothing bubbling from overflow.
No air bubles in cooling system.

Any thoughts on this? I do remember reading something about these swaps running on the hot side while highway driving, but I couldn't locate it anywhere when searching. I am not financially able to swap to an aluminum radiator at this point. The only cooling system upgrade I could swing right now would be 2 12" ebay electric fans. The E-fan swap is looking like a good option.

Thanks in advance for any insight on this issue.
 

veedubin

Official SM Decals
IBoughtASupra;1847892 said:
That's normal. 210 is a little high. I have seen them as high as 200 but under hot days with AC and boost.

Is there a shroud?

Forgot to mention that there is no shroud currently. I was also suspecting that to be an issue, but I also ran without on the 7M without the elevated temps I'm seeing now.
 

IBoughtASupra

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Mar 10, 2009
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Well the JZ tend to run hotter than the 7M. I along with Dustin have Aluminum radiator combinations and both of our JZ run at 190F. I had a huge tantrum about it because I thought it was supposed to be 180 but 190 is where try idle and up to 200 on hot days and highway is normal.
 

525gte

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Sep 19, 2011
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My buddies 2jge t runs at 195 200 also.maybe try a new radiator cap. Also some water wetter. I I run a 19pound on my 1 j.. and does it cool off once u turn on the heater?
 

te72

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Mar 26, 2006
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Perfectly normal sir. Keep in mind, that cooling efficiency is more about the fan than the radiator itself. If your fan can't pull enough air, it doesn't matter how nice your radiator is. ;)

Minor warning about Water Wetter though: using it WILL help you find ANY leak in your system. :p
 

veedubin

Official SM Decals
IBoughtASupra;1848088 said:
Don't use that water wetter nonsense. A good fan, clutch, shroud and radiator will cool the car enough.

Last time I used water wetter, it was used in a water only cooling system - as the bottle directed. I personally am not a fan of additives and such. If the proper fluid isn't performing as it should, I try to fix the problem. Ie guys that run 20W50 & motor honey because they have lifter noise.... :(

I will be ordering 2 12" electric fans tonight and ditching the clutch setup. I will also be mounting them on a custom shroud. Hopefully that will keep things a little more inline temp wise.

Thanks for the input everyone!!

Sent from my LG-P504 using Tapatalk 2
 

veedubin

Official SM Decals
hvyman;1848144 said:
Keeping the clutch fan is a better idea.

What makes you say this? I know there are threads out the you-know-what relating to clutch vs e-fan, but I haven't been able to locate any solid data to establish the clutch fan is a "better" option. I agree it is better when you look at simplicity of design. There are less components to fail, less work to install and make it function properly, etc... But I am more interested in airflow capability. As with most that go the E-fan route, I am ordering the eBay special slim mount electric fans. These fans are stated to move 1550 CFM each. Taking into consideration a 15% margin of "error" on their flow numbers (for manufacturing differences between units,dramatization of the units performabce, etc...), these fans should still move about 1317 CFM each. Combining flow from two fans should yield about 2634 CFM at full speed. Now I do understand that these numbers are highly subjective as there are no proper tests performed on these units to verify actual airflow. It is the only true numbers I have to work on. Using 2 fans mounted in a proper shroud, and the shroud sealed around the radiator core perimiter will allow all of the air flow to go directley over the core. Also running the fans in either a staged configuration i.e. One kicks on to control the temps, the second will turn on if the first fails to keep temps in check, will eliminate a lot of unecesary run time on the units. The other idea I was kicking around would be to utilize a PWM to control the speed of the fans. Either simultaneously or independently. Using a PWM would allow for a "soft start" to limit the high amperage spike on the electrical system as well as keep the fans running only long and fast enough to maintain proper engine temperatures. If you have or know a link to the CFM rating of a properly shrouded 7MGTE clutch fan setup, I am more than interested to see it.

hvyman;1848144 said:
Also getting a shroud is a good idea.
Yes, it is a great idea..... but finding a fan shroud in usuable condition is a bit of a pain, and most times when they are found in usable condition, it exceeds the cost of performing a proper E-fan setup. And the thought of going to Toyota to source the shroud...... I'm cringning just thinking about it.
 

hvyman

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Gaurentee those eBay fans are not going to flow as good as te clutch fan. Clutch fans always work good unless something takes a shit. It was there stock and has worked fine in stock and high hp cars. No need to reinvent the wheel.

Also dm sells new shrouds iirc for around 100$.
 

veedubin

Official SM Decals
hvyman;1848165 said:
Gaurentee those eBay fans are not going to flow as good as te clutch fan. Clutch fans always work good unless something takes a shit. It was there stock and has worked fine in stock and high hp cars. No need to reinvent the wheel.

Also dm sells new shrouds iirc for around 100$.

$100 is more than 2 fans, a PWM, a 2 stage temp sensor, and material to fab a shroud would cost. Cost is a big player for me.

3p141592654;1848167 said:
If you are running hot at 75mph, no fan is going to help you.
^Surprised you are the first to bring that up :icon_bigg This is the main concern I need to address. Along with the fan shroud I will be attempting to fabricate some sort of air diversion panels to aid in moving air over the radiator core.

IJ.;1848168 said:
Missing undertray?

The MKIII undertray is like the unicorn... Everyone's heard of it, but no one has ever seen it... :biglaugh:

On a serious side :3d_frown: No, I do not have one. I would like to have one though.
 

IJ.

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Mar 30, 2005
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At 60+ Mph a missing tray will be an 5>10c rise, they're available you just have to pay for it.

There will also be a heap of missing plastic blocker panels from around the Rad if your Mk3 is like most of the ones I've seen here, fucktards bin them over the years then people wonder why does my car run hot at highway speeds... :nono:
 

veedubin

Official SM Decals
IJ.;1848191 said:
At 60+ Mph a missing tray will be an 5>10c rise, they're available you just have to pay for it.

There will also be a heap of missing plastic blocker panels from around the Rad if your Mk3 is like most of the ones I've seen here, fucktards bin them over the years then people wonder why does my car run hot at highway speeds... :nono:

I know what you mean about the people throwing away plastic bits.... people are,well....er..... dumb. I do have some of the plastic/rubber air blocking parts, but most are damaged in one way or another. I'm looking at picking up a parts 86.5 here soon. Mabey those will be all in tact.

And when you say 5-10* you are talking celcius right? If so you are saying that running without and under belly tray will increase coolant temps by 41-50*F.... Seems a bit far fetched... I know that it will cause a decrease in airflow were it needs to go, thus allowing things to get hotter. I am waiting until I have the extra funds floating around to purchase one. I forget what the dealership qouted me last time, but it was borderline psychotic.
 

IJ.

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Mar 30, 2005
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I wouldn't have said it if I hadn't gotten the data points on my own car, while some may get away with the temp rise and bullshit on that they don't run a tray if your cooling system is marginal in any way and this includes a blocked/damaged Rad or AC Condenser core it can be enough to tip it over into "too hot" and never recovers.

Going faster only makes it worse as the air bypasses the rad and spills underneath and around the sides.

I had a bud do an alignment and he left the 3 bolts out that are directly under the rad support and it picked up 3c at highway speeds, I ran 25K of MoTeC gear in my car and everything was data logged..
 

veedubin

Official SM Decals
IJ.;1848201 said:
I wouldn't have said it if I hadn't gotten the data points on my own car, while some may get away with the temp rise and bullshit on that they don't run a tray if your cooling system is marginal in any way and this includes a blocked/damaged Rad or AC Condenser core it can be enough to tip it over into "too hot" and never recovers.

Going faster only makes it worse as the air bypasses the rad and spills underneath and around the sides.

I had a bud do an alignment and he left the 3 bolts out that are directly under the rad support and it picked up 3c at highway speeds, I ran 25K of MoTeC gear in my car and everything was data logged..

Seeing that my math is incorrect, I see the sense in your statement now. Thanks! And that is wild how three missing bolts creating an air gap would cause a temp increase. I really want to delve further into aerodynamics and the likes; not so much for a job, but for my own interest and entertainment.

3p141592654;1848208 said:
A delta of 5-10C = 9-18F. I won't comment on this country's science education....

Now to you sir.... I am missing a mathmetic equation for converting 5-10c into farenheit..... Care to fill me in. I was always in the top of my class for math and science. Granted it's been over 11 years since I was in high school, I'm sure I've forgotten more than I learned. I went off of a general celcius converter found here: http://www.wbuf.noaa.gov/tempfc.htm
As I'm thinking about this more, I am really curious how this works.

BTW Thanks for the info! :icon_bigg
 
Oct 11, 2005
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You are calculating the difference between two temperatures, not the actual value.

Let me give you a simple example, if there is no temperature difference measured, i.e. 0C, then what value would you expect it to be in Fahrenheit? Use you calculator and see what you get, then ask yourself if it makes sense.