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Cooling the 1KZ-TE motor:

My Aux temp guage arrived this morning while we were out, so as soon as I finished lunch, set about fitting it -
first off the sensor - plan A was to drop it in the water flow in the rad hose, but surprisingly I couldnt get the hose to seal with the tiny flat cable coming out from the hose connection point :(. So plan B, crimp a terminal to it and bolt it to the inlet:
IMG_1957 (640x427).jpg

Next job, dremmel the double din blanking plate to fit the meter and pinch a supply from the CB power supply, mount the meter, test and tidy up:
IMG_1959 (427x640).jpg
Once tidy, start engine..... and run for a few mins to see if it works!
IMG_1961 (427x640).jpg

Then off for a quick blast to get things upto temperature:

IMG_1962 (427x640).jpg

Then a test to confirm what I am seing is what the temperature is with my Laser guided infa-red temperature reader........

IMG_1964 (640x427).jpg

Gauge inside said around 80 degrees, laser thing said about 80 degrees, but when on the move, max temp was 74 degrees........ on fast idle for 10 mins after the run, around 80 degrees.....I think there may be a lower thermometer in the system as my fan is running all the time, even after start up, or is it supposed to?

I think if we see a sudden rise of temp from 80 degrees on the new gauge, then it could be time to panic!

It would be interesting to see what happens when things warm up around here, or if I ever get away to the mountains sometime ....... :)
 
Just for info I have 3 senders on mine and the exterior bolt on one runs about 9 degrees lower than the one in the water inside the top alloy outlet pipe! Also have one in the water in the bottom alloy pipe next yo the thermostat and that read 10 degrees lower than the top one. So if your running 88 degrees thermostats in the bottom it can easily be up in the high 90's in the top hose.

So you can see with the slightest cooling issues your up over 100 in seconds.

http://www.landcruiserclub.net/forums/showthread.php/49924-1-kzte-cylinder-head-my-delema/page2

as you can see in these pics of the upper sender and I now have a man radiator and fitted a lower temp thermostat. As I have the 76 degree thermostat in I also set the viscous fan coupling to come in earlier.

my temp now runs between 82-88 and the alarm comes on at 90 which I feel is far safer.
 
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Another thumbs up for Simon Holton - ordered a 76 degree thermostat from him last week, not a stock item, but ordered me one, it arrived yesterday without paying for it! He told me to ring him when it arrives and pay for it then - good man! of course, I (wifey) rang and paid straight away. Good service eh?

cheers Simon!
 
This has been an incredibly informative thread, thanks to everyone who has contributed and shared knowledge,I learned a lot in the last 30 min. I just acquired a 4runner with a 1KZ swapped in and its having cooling issues similar to the ones discussed. Has anyone actually put the inline thermostat housing in and recorded results yet? Tim B? Thanks for the info so far.
 
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Just fitted and 71 degree high flow thermostat from Aus which is listed as being for a 120 series so I wondered if Toyota had realised there was and issue.

after testing with a trailer on and up long hills I can't get it about 84 until I turn the air-con on and then it rises to 90, but still in the safe zone.
 
The other thing to remember is that the fan needs heat to work so you need to have hot water in the rad to start off with, so no matter how good your fans are they only cut in once the water starts circulating around the rad so it worth getting the thermostat to open sooner.
 
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Thanks Bob. Have bookmarked this one as it may come in handy for my predicament.
 
I know this is dragging on but!

i refilled the fan hub with 3000cst which I've seen on the original Toyota packaging on YouTube vids and vario use post which worked fine around here at around 19 degrees but shortly after read on an NZ forum that the Toyota oil is 10000cst so ordered some of that as well and took with me!

I headed off to the pyrenees via Spain on a ferry and as soon as I headed off the boat it's 30 degrees! And the first long climb I come across up goes the temp and my alarm goes off at 95. With the fan only half working So we made camp and I wipped off the fan and hub and refilled it with the 10000cst stuff and thankfully running perfect.

Most days the temp outside reached 30 and only on the longest mountain passes with the air con on the engine reached 90 and would quickly drop down to 84 with air-con off.

On the way back up across France yesterday driving 76-80mph it ran between 75 and 84 degrees on hills.

so all is cool at last

just to recap, I'm running a 71 degree high flow thermostat (which said on the packaging for a LC120) and refilled the fan hub with 60ml of 10000cst oil and the fan is set to fully lock up around 84 deg. Oh and a Allisport radiator.

Hope this helps.

http://neuralfibre.com/paul/4wd/tuning-and-understanding-your-toyota-viscous-fan-clutch
 
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Best thing that I did to stay cool, after the fan oil change, was to fit a stock intercooler like all the Aussie Prados have.
 
Paulsven,this is a good site for 1kzte. (DSL-Toyota 1 kzte). I am sure you will find all the info you require
 
Hi Bob I am based in Africa and I am an off road rally car driver. I have a fully modified surf with a 3rzfe engine petrol. I intend on changing the engine to a 1kzte inter cooled engine but need to chat with you further over you great post on the over heating problem with the 1kzte. I will be rallying in 45 degree c heat and in escarpments and very low speeds and would like to know if your theory above finally worked with as it's an old post from 2010 and you must have more info by now. Here with my email address [email protected]
 
Hi Bob thanks for your great post. I am based in Africa and I am an off road rally driver I do severe off road driving with a fully modified toyota hilux surf rzn185 2.7efi 3rzfe engine. I recently fitted detroit lockers to the car front Nd rear. I have noticed as much as I have traction the engine is at it max and cannot perform on the high slopes where I need it most. I am thinking of going for a 1kzte inter cooled diesel motor which I know for a fact will be a straight fit if i convert the car to dispel as I currently use a diesel chassis with the current engine.
I would like to know if you tested your car after making the changes you talked about a while back? I will be rallying in 45 degree heat at very slow speeds and lots of climbing with low torque needed. If I cannot sort out the cooling on the 1kzte I might have to look at other options... Please kindly email me with your findings I would really appreciate it my email is [email protected] thanks so much
 
I fitted a bonnet scoop and fan (with shroud) on the intercooler to help with slow speed cooling. I haven't rallied mine... But I've dragged a camper trailer on the beach here in Australia and haven't had any heating/cooling issues. I also fitted an auxiliary ATF cooler inline and my vc fan is always on. I also removed the throttle body butterfly for better off idle pick up.
 
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