Summer Desert Temp Readings

[bmac1996acc]

Yes, the IAT is measured by the MAF.

I don't live in a hot area like you, but it seems to me that Toyota knew what they were doing when they designed these rigs to run all over the world in high heat areas.

Didn't they use secondary electric fans in other high heat areas?

 

[Tools R Us]

I'm running as high as high as 208 uphill in 110F weather A/C on. Idling runs around 203. Stock '97 LX w/113K. 10K in the clutch below if anyone can identify it. You think 20-30K would help much?
https://forum.ih8mud.com/80-series-tech/404015-97-fan-clutch.html

Your numbers, aren't something I would worry about. That clutch is an Eaton, IMHO a good clutch, I run 15K+ in them.

 

[96r50]

Didn't they use secondary electric fans in other high heat areas?

The only secondary electric fan I am aware of is the A/C condenser fan that was available in some markets. I don't recall if it was part of the rear A/C or cooler box options, but I'm pretty sure it was due to the additional A/C load. There are plenty of 80s running around the US with no cooling system modifications, only proper maintenance.

I'm just saying that I would prefer to fix the underlying condition (poor cooling performance) before cutting holes in the hood to relieve the symptoms (high engine temperatures). Granted I don't live in the desert, and hopefully never will

My 2c

 

[Dave 2000]

IIRC the air con compressor shuts down when the engine gets too hot, if your model has the electric air con fan this stays working during the compressor shut down period....makes sense.

regards

Dave

 

[Tools R Us]

The trick to good cooling is good, controlled, airflow and cooling system maintenance. All of the seals are important, radiator foams, hood to core support seal, tin between the frame rails under the radiator, fender well strips, etc.

A good preforming fan clutch is critical. In my experience, the early blue/black hub Aisin clutches are the strongest, Eaton slightly less and new blue Aisin is the weakest. This determines the viscosity of fluid to use, the new blue hub needs over twice the viscosity to come close to the earlier Aisin clutches. For desert conditions my starting point is; 10K for early Aisin, 15K+ for Eaton, 20K+ for new blue. On the new blue, some have reported good results with 30K, my experience ends with 24K, will be playing in the 30K+ range soon. Some experimentation maybe needed to find your "sweet spot", but playing with the clutch is easy, effective and cheap, so this is my first step.

My indicator for "enough" viscosity is the ability to slip properly tensioned belts, with a quick throttle snap, after a full heat soak. This is easy with an early Aisin, have never been able to get a late Aisin to do it.

Electric pusher, run it if you prefer, but in my experience is that there is plenty of power available in the clutch to do the job. Have seen them increase temps at idle/stopped. The only advantage I see is after run cooling, if that is important to you? I don't see any advantage or enough to warrant the added complexity and disadvantages.

Once you have good airflow, recheck your underhood air temps. There will always be heat soak when stopped at idle, but with a strong clutch, the numbers will drop. In my experience, well into the "not a problem" zone. At cruise I have always seen the area over the motor being the hottest, driver's side fender slightly cooler and passengers side the coolest. So if you vent at the edges of the hood, you vent the coolest air, it will be replaced by hotter, fan output temp air, I have seen intake temp go up. If I were to vent the hood it would be the hottest place, the center of the hood, but don't see the "need". I have never seen improvement in any temp that matters on the ones with hood vents that I have played with.

 

[Tools R Us]

IIRC the air con compressor shuts down when the engine gets too hot, ...

The other mode is high side pressure too high. This somewhat common with low airflow in hot conditions.

 

[94SRUNNER]

As always Kevin your posts on engine cooling (more importantly the fan clutch issues) are invaluable tools for anyone serious about there Land Cruiser maintenance. I hope more folks will take note and follow your guidelines.

 

[TJ96TLC]

So, My new blue fan clutch with 7k is too low??? Should I run 10k+ for the Southeast?

 

[94SRUNNER]

I will let Kevin confirm this, but I believe he suggests starting with approximately 20Kcst fluid in the new style blue hub fan clutch. Read through post 25 for confirmation.

 

[Tools R Us]

So, My new blue fan clutch with 7k is too low??? Should I run 10k+ for the Southeast?

My theory is; if it works, run it, if you feel there is room for improvement, play with it some more.

 

[TJ96TLC]

The stores around here have 30k and I have some 10k, can I mix this stuff?

 

[96r50]

As always Kevin your posts on engine cooling (more importantly the fan clutch issues) are invaluable tools for anyone serious about there Land Cruiser maintenance.

x2, great useful info as always! Thanks.

The stores around here have 30k and I have some 10k, can I mix this stuff?

You can, but I'm not sure how to calculate the end result.

 

[Ebag333]

You can, but I'm not sure how to calculate the end result.

I think going with simple math is close enough. 50% 10k and 50% 30k should give you roughly 20k. Or at least close enough to it for our purposes.


I'm currently using only 6k IIRC in my new blue hub. I get the startup roar when it's cold out, but not when it's warm out. I think I'm going to bump up to 15k after hearing Kevin's pondering on the meaning of life and how the weight of oil affects it......

 

[Tools R Us]

I think going with simple math is close enough. 50% 10k and 50% 30k should give you roughly 20k. Or at least close enough to it for our purposes.
...

Close, ~17K, ~1/3-2/3 for ~20K. This is the calculator that I use:

R/C Calculations

 

[TJ96TLC]

I saw that calculator too...I think I'm goin 50/50 for the 17.5K. How much usually drains out?

 

[Tools R Us]

... How much usually drains out?

It doesn't matter, but most that I have measured were ~20-40ml. What matters is getting as much as possible out. My fill is ~40-50ml, depending on which clutch and how clean. About 40ml will work for any of them.

This is how I drain Aisin clutches, note the hole at the bottom on the front (reservoir) side. If not at the lowest point it wont fully drain.

This method isn't best for Eaton clutches, for them see the later post in this thread.

 

[96r50]

I think going with simple math is close enough. 50% 10k and 50% 30k should give you roughly 20k. Or at least close enough to it for our purposes.


I'm currently using only 6k IIRC in my new blue hub. I get the startup roar when it's cold out, but not when it's warm out. I think I'm going to bump up to 15k after hearing Kevin's pondering on the meaning of life and how the weight of oil affects it......

One thing I learned somewhere is that simple math is never that simple

I have 15k in my blue hub now, and I wouldn't hesitate to go to 20k if I have it out again. Given that my climate seems to have a larger temperature variance, I'd say you should be ok with 15k, or you could just go straight to 20k

 

[dgerst]

Your numbers, aren't something I would worry about. That clutch is an Eaton, IMHO a good clutch, I run 15K+ in them.

I've got some 20K on the way to try out. Thanks for ID'ing the clutch. I was running 195F today after idling 20 Min with A/C on in 95F ambient so I'm not too worried, but a few degrees cooler can only help.
Thanks again,

 

[TJ96TLC]

Drained it about 30 minutes, I'm guessing about 20ml and added that back in 30K. I definately noticed a difference. I think I'm good where it landed. Its 98deg 70% humidity and its doing good.

 

[kidglove13]

Not the desert.
100* with about 60% humidity
Heat index 110*
Rolling terrain
A/C on
Temps according to manual temp gauge 192-205 depending on engine load.