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Safe running temp (water-temp) for JDM 2JZGTE?

29K views 29 replies 19 participants last post by  -Defi- 
#1 ·
I am driving a buddies car this weekend, and he told me to keep an eye on the temp, we have an aftermarket water temp guage from Apexi in the car. What is the safe range for water temp? And at what point should I pull over?
 
#3 ·
I understand if you road race but if you have to keep an eye on the water temp for some normal driving and some pulls here and there than something else is wrong lol....
 
#4 ·
I am checking in for the same info..... I see 195-205 when driving around in 85 degree weather. Once the temp go over 205 I don't do any hard driving. My haltech will start to flash red on the temp gauge above 217 but I know on other cars (GM, Fords) they have the cooling fans come on at 225 to 230. What temps do you guys read when crusing?
 
#5 · (Edited)
Well, the car is a fairly fresh build, so we havent had alot of experience with it yet, but worry about it getting warm. Its a E36 M3 with a 2JZ-GTE, not a Supra. So there isnt as much room in the engine bay. Thats why it gets hot.

We have an Aftermarket Aluminum Radiator and Electric fans. I just want to know what is a safe running temp. My Nissan runs around 170 degrees *F, and I know that these 2JZ's run a bit warmer than that.
 
#10 ·
205 should be fine. I know it's not apples to apples, but both of my previous Z06's were happily in the 220-230 range driving around town and 200ish when cruising on the highway or doing pulls on an open road. My 3000GT/Stealths were fine in 200 range, but were a little happier in the 185-190 range.

FWIW, I don't have an aftermarket temp gauge in my Supra, but I've observed no difference in trap speeds between being relatively cool and sitting in the staging lanes in the summer heat idling for 30 minutes.
 
#11 · (Edited)
One really hot days idling in traffic with a/c on, if the temp stabilizes at just under 100 degrees Celsius that's ok. If it continues to go up, you should start looking into things. Some guys run slightly higher, up to 103 degrees Celsius when it stabilizes, and their cars run fine, no overheating whatsoever but that's like 40 degrees Celsius or higher ambient temps.

And another thing, make sure the power supply of your Apexi gauge was done right. If it was wired poorly, the gauge becomes highly innacurate as the temps get higher. Before we fixed the wiring on my DEFI gauges, by the time my AEM ECU reads 85 degrees Celsius, my DEFI was showing 95-98 degrees Celsius and the temp reading on the gauge would fluctuate a whole lot! As much as 5 degrees difference as the needle would swing and play around a lot.
 
#12 ·
One really hot days idling in traffic with a/c on, if the temp stabilizes at just under 212 degrees F that's ok. If it continues to go up, you should start looking into things. Some guys run slightly higher, up to 217.4 degrees F when it stabilizes, and their cars run fine, no overheating whatsoever but that's like 104 degrees F or higher ambient temps.

And another thing, make sure the power supply of your Apexi gauge was done right. If it was wired poorly, the gauge becomes highly innacurate as the temps get higher. Before we fixed the wiring on my DEFI gauges, by the time my AEM ECU reads 185 degrees F, my DEFI was showing 203-208.4 degrees F and the temp reading on the gauge would fluctuate a whole lot! As much as 41 degrees difference as the needle would swing and play around a lot.
Translated..... LOL
 
#13 ·
rb,
Like you just did here, a not uncommon error is converting degrees temperature DIFFERENCE from C to F as if was the actual specific temperature.

botch said "5 degrees difference..." meaning 5C difference which you converted to 41 degrees difference (meaning 41F)

But to be correct it should actually be 9 degrees F difference:

 
#16 ·
that sounds sort of like "I had high oil temps so I unplugged my oil temp gauge" ...?
 
#17 ·
Lol when i said 5 degrees difference, i meant that the needle on my Defi gauge would fluctuate between say 93-98 degrees Celsius randomly :)
 
#19 ·
Do you have an oil cooler installed? That might help a little. Are you running the stock M3 facia? Those can be a little restrictive. Also what about the bottom cover plate (plastic thingy). Keeping that on an M3 is important for airflow.

Jeff

99 M3
95 Supra
 
#21 ·
Just drove around today and after getting stuck in traffic a bit my water temp was at 80 Celsius
It was around 25-27 Celsius in the sun today

I highly doubt my temps would go much over that unless boosting like a madman
My engine bay gets so hot you can't touch ANYTHING for bout 10-15 min after driving for a while
 
#22 ·
Since, as someone stated the thermostat, is 180 degrees.With my temp gauge sensor on the engine return hose, I see 200 degrees.When it 90+ degrees outside, like yesterday, It can go up to 220 while sitting in traffic.While tracking the car at Vir, 220 was as high as it got.If you are willing to put a fan on the backside of the frontmount to blow into the radiator, it should help keep her cool.Its all about airflow.

Philip 94TT
 
#23 ·
You guys also have to note that most aftermarket gauges read slightly higher than actual as a sort of built-in safety factor that gives you some time / leeway when things start getting interesting.
 
#24 ·
Are you serious? Why would an aftermarket gauge read hotter than it actually is? I've never heard that.

I have a freshly swapped 2jzgte in my 95 240sx and am starting my battle against high temps. Yesterday when driving, the car settled at about 195 degrees at idle most of the time and went down while moving and even under boost as long as I had good airflow through the bumper. I got pretty worried when it hit about 220 but it never overheated and I consulted the supra shop that works on my car and he said not to worry too much about those temps. It only got hot when not in motion. The reason my car runs a little hotter is because of the lack of engine bay space between the electric fans and the front of the engine. Its crammed in tight. I am going to consider a vented hood even though I don't like the way they look on 240s.
 
#27 · (Edited)
Are you serious? Why would an aftermarket gauge read hotter than it actually is? I've never heard that.
I've had tons of experience with this when I was having my cooling problems in my Supra / 2JZGTE.

I've checked out so many cars local to me (Silvias, Evos, STI's, Skylines, Civics and R35 GTR's) by comparing their aftermarket temp gauge readings with an OBD scan tool (Cobb AP or Scan Gauge II or the shop-grade LAUNCH Scanner) plugged into the OBD port (or the tuning software in a laptop connected to the stand-alone ECU) versus the readings on the after market gauges. The readings can be off by as much as 2-10 degrees Celsius when measuring between 82-100 degrees Celsius; the hotter the temps got, the greater the difference between the ECU and the gauge. As an example, my DEFI gauge was reading 97-98 degrees Celsius but quickly went down to 1-2 degrees Celsius higher after a few minutes idling in the dyno room but my AEM was only showing 84-85 degrees Celsius. We were doing some sustained part-throttle runs (as much as 30 seconds revving at 4k RPM) to get a start on part-throttle tuning back then.

And it's not just temp gauges. I've seen boost gauges and pressure gauges reading slightly higher too when compared to internal ECU logs versus watching the replay of a DEFI BF gauge with the Link system.

I do admit that the vast majority of cars / gauges I tested were JDM brands like DEFI (most popular), HKS, Omori, A'pexi and some Blitz gauges so it MIGHT be a JDM thing.

okcomputer, get an ATI dampened crank pulley and set your idle a little high, like 950-1000rpm. The oversized crank pulley will spin your water pump faster, pushing more cooling through your engine and into the radiator, helping it cool faster. Your crank will also love you for it. The slightly higher idle will also help speed up coolant flow. You will have to tune and adjust ignition timing and AFR at that RPM though otherwise you can potentially overheat as your ignition timing will be too advanced at that RPM point and your AFR might go slightly lean as well, making your cooling problems worse. These were my problems, and after Mikey / Pineapple Racing saw my map, he saw and knew immediately and did the necessary changes for me.
 
#28 · (Edited)
i have a 2jzgte in my fd. running distilled water, koyo rad, fal fans, and aem temp sensor in the upper rad neck housing.

in houston right now (was around 100-105*F ambient last week) i was getting about 195-199*F in light to light traffic. on the freeway its about 190*F. ive never seen it go over 200*F unless i was low on coolant or had a leak. and its hot as hell in houston

edit:

oops bumped an old a$$ thread... lol oh well
 
#29 ·
My th400 95 car with a 3.77 turning 3400 rpms at 70mph doesnt get over 205. I was shitting bricks at that temp. So you guys are saying that 225 is NOT going to over heat the engine? Does anyone know for a fact what temp is blow head gasket temp?
 
#30 ·
The only thing I can think water wetter does is expand faster than water causing the thermostat to open sooner. I wouldnt use an extra bottle as that is just a bandaid for a deeper issue. Try ducting the radiator and intercooler and be sure there are under trays on the vehicle. There is a reason cars have under trays to begin with and it all has to do with creating a nice seal so only the cool air comes in. Besides it also keeps the heat from the road out of the engine bay as well.

Ducting the radiator and intercooler will do wonders.
 
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