Cooling the 1KZ-TE motor:

[Shayne]

A new rad dropped my factory gauge needle maybe 1mm at the tip of the needle which may not seem much but at least i know i'm running nearer the low end of mrT's temperature gauge blind spot . Can't get a thermostat until next week so it will be interesting to see what difference that makes . Shame i haven't yet fitted my aftermarket gauge to give more accurate readings but there you go .

 

[Beau]

Thanks Beau but my trucks in bits and i have ordered a 76 stat from Simon just because i can , I do have to wonder if its even necessary to put a lower rated stat in given my truck shows no problems that aren't caused by the broken cowl even with 1/3 of its radiator blocked and serving no purpose .

Can i ask did you by any chance buy your truck from a gentle soul who probably only drove it when it was too wet to ride a bicycle ?

I did ask myself if a 71 degree stat would be too cold, But Toyota actually fitted a 71 stat on the 2008 models 1KD engine which made me think they did so for a reason, and both engines are pretty similar, especially the block end! To top it off, I'm in Florida where average temps year round is 30 degrees. So I think running cooler is better than being on the hotter side of things! Being that your gauge actually moved with the new rad shows you were running more on the hotter end, but not into extremely bad temperatures.

I'm not too sure on the first owner as it was a dealer, but when I bought her she only had 20,000 miles and was 2/3 years old. Why'd you ask?

 

[froggy Steve]

Update....new Rad fitted, it has made a difference but not as great as I hoped it would. Havent had the high 30's temps and push up a long hill yet, but it appears to be running perhaps 5-8 degrees cooler bumbling about, up hill and down dale.
Also had the auto box extra rad fitted - right against the air con rad, slap bang in the centre. He has plumbed it in as per instructions in the box, ie after the normal rad. I cant tell if its made any difference though, I havent got a oil temp read out for gearbox, but it must be doing something!



Time will tell if the cooling overall is much better when we get the scorchio temps back

 

[parnavaz]

IIRC, you dont have an after market Temp gauge, but rely on the Toyota one? My Toyota gauge didnt move until my digital after market one said over 100 degrees! (105 I think it was) And to think I 'think' have cooling problems at 95 degrees ...........the Toyota gauge wont tell you this.

Normal flat roads legal speed running, temps at 78-85, big hills and it creeps up to 90-95, big longish hill 95 + (and the one time scary 100+) I dont EVER want to see the Toyota gauge rise again, hence new rad!

Where have installed the aftermarket Temp gauge?

I plan to do the same mode and have 2 options.

1. to cut the upper radiator hose in half and fit the sandwich pipe with sensor (which I do not want to do as the hose is been in 2 dimensions )
2. to drill a hole in the alloy pipe between upper hose and the head. (which seems much harder to do and will not allow me to fit stat, if I make my mind to fit one on the hotter side of the head).

Can you throw in some pix, please?

 

[froggy Steve]

The sensor just slipped in the top hose wher it joins the rad, with a bit of silicon to seal it all in.
Thrashing around the tiny b roads this afternoon, I managed to get it up to 81 degrees! Much happier now, new rad has done the trick along with the new oil cooler (auto box). I can climb hills with confidence now!

 

[Shayne]

I bought one of these but my gauge came with a screw in probe .

 

[parnavaz]

steve

could you please take a photo of it, whenever it is comfortable for you?

shayne

yes I intended to buy the same stuff. BTW what is the inner diameter of the hose?

 

[MarkW]

You could also use one of these self sealing hose take offs



https://www.merlinmotorsport.co.uk/s/samco-hose-kits/self-sealing-take-off-s

 

[Shayne]

Well lucky for you if unlucky for me i have 2 radiators sitting in front of me now and the internal diameter of the inlet pipes are 35mm maybe 36 .

 

[parnavaz]

Mark

I just do not feel secure about drilling the hot side hose and inserting a sensor in it

 

[froggy Steve]

all I did was remove the hose and drop it in, no drilling or anything, the wire runs between the rubber and the metal tube - it was a flat wire, sensor is in the water flow.

 

[Beau]

Has anyone plumbed in a trans rad by itself, eliminating the main radiator? I would imagine it'l be just an Air cooled rad. How big would it have to be to cool the trans effectively? Asking because the milner rad I have is rusting around the inlet pieces on the trains section and would rather have the trans cooled separately if possible. It would also eliminating the trans adding heat into the main rad.

Also, has anyone fitted a oil cooler to these engines with any success? Is it needed...or worth it? I have a oil filter sandwich plate so getting an oil feed isn't difficult. I'm thinking it'll put less strain on the cooling system?

 

[froggy Steve]

I had a aux transmission cooler fitted along with my new engine rad. Normal running temps are down to 77, 78, freewheeling downhill drops it to 75, 76! Hottest its got so far is 95, foot flat to the floor dragging its bum up a long long hill in spain. As soon as i dropped it out off overdrive, and used the gearbox, dropped to mid 80's.
The aux transmission cooler is in line with the new rad so oil gets 2 chances to cool before it goes back into the box. Any heat I can take away from the head is good in my book

 

[BobMurphy]

Also, has anyone fitted a oil cooler to these engines with any success? Is it needed...or worth it? I have a oil filter sandwich plate so getting an oil feed isn't difficult. I'm thinking it'll put less strain on the cooling system?

The 1KZ-TE has a water-cooled Oil Cooler under a plate on the side of the block behind the Oil Filter (is this what you are referring to??).

I don't recall anyone fitting a separate external oil cooler.

Bob.

 

[Beau]

The 1KZ-TE has a water-cooled Oil Cooler under a plate on the side of the block behind the Oil Filter (is this what you are referring to??).

I don't recall anyone fitting a separate external oil cooler.

Bob.

I understood it had a internal oil cooler. I was questioning whether another external air cooled one would be of any use.

And I know a lot of people have added a rad inline with the normal cooler, however I was wondering if it would be possible to cool it all together from a separate rad completely.

 

[BobMurphy]

Certainly possible to cool the engine, Auto Box and Engine Oil via separate rads. I would worry about over-cooling, but then I live in Scotland .

If you are using the truck hard in a warm climate it may be worth considering. I would be inclined to have a thermostatically-controlled by-pass on it as well though.

Another interesting photo sequence on the way . . . .

Bob.

 

[Beau]

My main reason for isolating the trans cooler is so there's no chance of water contamination with a failed radiator unit. And the milner rad I have is already looking in bad shape after a few years.

Temps here in Florida on average all year round are 25 degrees+ with days as high as 35+. Only at night time during the winter does it ever get below 20 degrees, but never single digit. This is why I'm seeking ideas and help on cooling the motor down further.

 

[alfa]

gut gemacht

 

[Shayne]

Been mulling this over again recently and i remember suggesting a while back in this thread that the positive crank ventilation PCV might have something to do with the problem .

I had a new rad , new thermostat and new coolant a year ago which has all got to help to say nothing of the 3" exhaust downpipe and while pushing the limits for about 1800 miles in two days and pretty much daring the head to crack , i think i encountered the PCV phenomenon .

Using new and genuine Toyota semi synth engine oil (is it 5/30 ?) i was forced to add another 2 litres during the journey .

Now were talking warm weather , aircon on and 75 - 95 mph for hours on end and obviously concerned by the amount of oil she was using i did a little reading when i got home about how engine oil breaks down to dissipate heat .

Fairly sure i had my answer as to where the oil was going and reasonably confident i had nothing to worry about i decided on a wait and see approach . 6 months on i am not losing oil and there are no leaks so where did the oil go .

Coincidentally i split the pcv pipe on the same journey perhaps preventing at least some of the oil mist being mixed with fuel and fired in the chambers .

 

[Beau]

Shayne, interesting scenario for sure. I've pushed my truck at those similar speeds before for extended lengths and never had a problem with oil burning. I imagine what you're referring to is the oil mist entering the turbo inlet side and eventually burning through the engine. 2 litres is quite a bit of oil though, I'd be slightly concerned but it seems like it's only doing it when you push the motor, maybe the oil is getting too hot? A different kind of oil may help change things too? 2 litres though is a lot to burn through just the crankcase?

Prior to installing my oil catch can I was 100% having oil entering the intake via the crankcase breather. It wasn't enough for me to notice during oil changes in the dipstick but was causing a little leak around the intake side gaskets over time. I now have had my catch can on for a good 5000 miles and it's worked well. It hasn't yet registered any oil on it's level, butt yesterday I had the intake cross over pipe off and it's clean as a whistle. I could still see my fingerprint from the previous time I swept across the oil.

If you're losing oil this way, I would highly recommend investing in one. They're cheap and easy to install. Just get one half decent with a inside baffle/filter.