HZJ75 still overheating, viscous fan questions!

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The cap has 16lbs written on it... will replace it anway when I find a parts store, they are cheap!

I have been to 3 radiator shops in latinamerica, they were very primitive, not really what you know at home.
But the radiator started to puke vapor when the stock temp gauge was just below red, when it's at 3/4 it still doesn't "puke" vapor, so I guess it does hold pressure? I thought the stock gauge at 3/4 means more than 120Celcius?

Aussie 25 - Fan I tryed to stop when colt with a rolled paper magazine, it wasn't possible, but I could slow it down.
When hot NO way I could slow it down, it just destroyed the paper magazine!
But what do you mean with foam between A/C and radiator?

I will buy a digital gauge that I will connect to the inlet and outlet hoses (bolts) to check REAL temperatures and also to check how the radiator performs!

The oil pan I thought would help cooling, but I guess a small oil cooler with fan will be much more effective!
But I think I got nowhere a space for such a cooler...
The only thing that would fit would be a Heat Sink Cooler but I don't think they are very effective...
I just don't like the idea of having the oil increasing up to 130Celcius!
 
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Mate, If I stuck in a place where you can't get parts for the fan I would put 4 or 5 small diameter bolts right through the viscous coupling locking it solid, and replace it later. Bit rough but I have seen it done and better than cooking the motor. You can lock up the fan by overfilling it [fill it right to the top when apart]. However if your fan is leaking overfilling will not last. If leaking there should be black sticky oil around the hub and onto the fan. Make sure the bi-metal spring is not broken off at either end. These springs can break very close to the hub it should move from hot air if you put the match very close to it this may cause it to not give a correct indication of movement when heated by hot temperature from the engine, use a hair drier or heat gun about 6 inches away. Is your radiator clean as they tend to clog down in the bottom?
Don't forget if you fit a deeper sump it is better to fit a longer oil pick up and filter on your oil pump.
 
I will put a piece of cloth or gasket in there, my friend told me it works too and you can remove it again when I get the 20'000Cst Oil (from Europe, here you won't get anything like that!)
bi-metal spring works, I rechecked that few days ago again!
Didn't see any sticky oil anywhere, but will look again...
 
Pull the thermostat, lock the fan, turn on the heat to full with cabin fan on full...think of this as aux. cooling or pretend you are Finn in the sauna.

What elevation are you at?
Your boiling point will drop with elevation.
 
Bought a new Century made in Japan radiator cap today and pressure washed (Carefully) the radiator fins, they had little bit of mud.
The cabin heater didn't change anything, that car was too hot to get cooled by this small cabin heater!
When the car was cooking I was at 3000-3500meters over sea level!

I will drive tomorrow up to 4600meters, let's see how it runs!
 
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  1. bigbrowndog
    Messages:
    1,633
    Location:
    N.Q. australia

    Just looked this up to find out what cSt means. It looks the same to me...
    search showed...:eek:
    The standard unit used to measure viscosity is the centistoke (cSt). According to the Automotive and Industrial Lubricants Glossary of Terms:

    Viscosity is ordinarily expressed in terms of the time required for a standard quantity of the fluid at a certain temperature to flow through a standard orifice. The higher the value, the more viscous the fluid. Since viscosity varies inversely with temperature, its value is meaningless unless accompanied by the temperature at which it is determined. With petroleum oils, viscosity is now commonly reported in centistokes (cSt), measured at either 40°C or 100 °C (ASTM Method D445 - Kinematic Viscosity).

    The centistoke rating is converted into the SAE weight designation using a chart like the one shown on the Superior Lubricants Web site.
    bigbrowndog, Jun 27, 2006 Edit Delete Report
    #101 + Quote Reply

  2. Tools R Us Moderator SILVER Star
    Messages:
    17,563
    Location:
    Chandler, AZ
    landtank said:
    I'm finding plenty of places that sells the oil in 50ml bottles, but it is in weight measurements. Like 3000wt, 10000wt and so on. The prices are likw 8.00 a bottle which would seem to be a single charge for our clutches.

    I just can't confirm if the wt class is the same as cSt.

    They use it in the diff gearbox of RC cars.​

    Cool deal, the hobby store bottle I have (100 wt, very thin) is 10ml and was $9.95. We use a trace amount in some of our rocket fuel formulas as a plasticizer. For the fan clutch to work properly we need pure silicone fluid, wonder if the hobby store stuff has additives? It's for "diff lock" on RC cars, so it may work on the same principle? The same fluid is used in the viscous coupler on our trucks.

    The tech rep from Clearco is suppose to call in the morning, hope to get some questions answered. But they start talking about stuff like Newtonian fluids, pseudoplastic changes, rhealogical behavior, etc., that stuff starts sailing by me and I am not as fast as Beowulf at goggle so I fall behind!:crybaby: :D
    Kevin Patterson '96 LX450 '84 4x4 Mini '73 FJ40
    Tonto Recreation Alliance
    "We have come to the conclusion that we can run our car over any road that a man can take a team of horses and a wagon, providing we can get traction." Dr. Horatio Nelson Jackson, 1903
    Tools R Us, Jun 27, 2006 Report
    #102 Like + Quote Reply
 
Thanks.. read it all, took me about 3 hours!

I will have to wait a few months till I get other silicone oil. For now I will have to stick with the about 65ml of 8000Cst oil in there.
I also bought a new radiator cap (Made in Japan).

I also washed the car and did power wash the mud I had in the radiator. Wasn't much, but still some mud between the fins when we drove through Colombian mud roads.

I did climb a hill today from 2500m to 4200m in 2nd and 3rd gear (wasn't not super steep). Oil did go up to 110Celcius, no more! Seems to work better now!
We are now at sea level again (30Celcius) and in 2 weeks going to drive back to Quito at 3000m from seal level. I guess this will be a good test!

If I open the hood on the front, is that a good thing or a bad thing? And why would foam between condenser and radiator help?
 
open hood in back seems to help .. ( I type seems coz I don't have scientific way to prove it ) but don't thing front will do .. again no scientific test here about that ..
 
If you want a quick easy way to permanently fix your fan clutch solid is split it open clean it and fill it with silastic. Fan then matches engine rpm. Worked for me til I got a new one on a hj75 out bush once. Slight loss of power tho. Bolting doesn't work to well as bolts will keep working loose.
 
Ok, I am at sea level now, 30Celcius (86F) and I had A/C on all the time. I drove on highway at 70kmh, did some small 100-200meter hills, the oil NEVER went over 90Celcius! Hood also felt cool...
I will do some serious 3000m mountains when returning to Quito in 1 week BUT yesterday at 4000m I noticed some black smoke out of the exhaust!
Now the BIG question: will an 1HZ with Turbo and Boost Compensator be too fat at this altitude? Is that maybe a reason why it's generating more heat than usual? Or will the Boost Compensator made up for the higher altitude? So why did it smoke black? It did smoke MUCH less black than my buddies 1HZ without Turbo (this one was reeeeally smoking bad!), but I still think it was running fat due to lack of oxygen.
What are your thoughts?
 
actually at altitude you should use less fuel .. not more, so boost compensator should not do a thing under those circumstances ..
 
Should or it does? I didn't change the max. fuel screw or changed anything on the Boost C. It was adjusted back then in Vancouver (sea level). So the question is what this setup does at 4000m or even at 5000m? Will it inject automatically less fuel (and adj. like that for the altitude) or will it overfuel? Does the Boost C. have an altitude compensation? I had an HAC before it was changed for a Boost C. in Vancouver, although I was told it only works upt o around 3000m...
 
The only comments I can add are ..

1. At altitude with less Oxygen available you are able to burn less fuel, so less fuel needed

2. Main function of HAC are restrict the amount of fuel injected, dunno how much or up to which altitude are good to

3. Turbo intercoooler setup will help at altitude for sure, to a certain point

4. Black smoke it's a classic symptom that you are injected more fuel than you can burn/use
 
that's my point Tapage... I got an 1HZ with Turbo and Boost Compensator at 4000m and higher and I was asking myself if the overfueling (due to lack of oxygen) might also be a reason of overheating??
I wasn't sure if the Boost Compensator will compensate for higher altitude, seems like not?
Can I just turn the max. fuel screw on the IP to lessen the fuel that is injected when I am at high altitudes?
 
Blade said:
I wasn't sure if the Boost Compensator will compensate for higher altitude, seems like not?
Click to expand...

boost compensator do that .. . compensate with fuel when boost it's present ..
 
measured today the radiator top tank and bottom tank temperatures with infrared tool (put tape on it to get right reading! I am aware of emissivity) right after driving at 34Celcius (93F) ambient with A/C full on at 60kmh for 30min. Fan was pulling pretty much air! Top Tank: about 82Celcius (180F), bottom tank about 78Celcius (172F).

Did the same test on parking lot, engine running at 1000RPM for 15min with AC full. Hood was already very hot to touch! Top Tank: about 91Celcius (196F), bottom tank about 88Celcius (190F).

I read here that 10F difference between top and bottom is normal and that no matter how big the radiator is you will never get more?

http://www.arrowheadradiator.com/14...apability_in_high-performance_automobiles.htm


Will do the same test in a few days when I will climb from sea level to 3000m!
 
not normal in my books you still have higher readings with no load on the engine ( other than AC ) than driving it with some load ( flat road ? ).
 
yep, idling with AC on generates LOTS of heat, always did, even now with almost locked up viscous fan!
Only thing that stops this is opening the hood, then the temperatures will drop quick!
In Mexico 12 months ago at 38Celcius air the needle went to RED when I did idle for 30min with AC on. I had to open the hood and it would go down...
That's why I lifted the hood in the back, I got the feeling that the air can't escape in my J7 engine bay!

I will remove soon the mosquito mesh on the front grill, I am pretty sure that harms the air and there aren't as many bugs in the Andes as were in Canada!

Question: does the J7 have any radiator ducting on top or bottom? Would this help in any way? I saw there is 1-2cm space between radiator support and radiator. Would it good to cover that on the top and on the bottom?
What about a hood-radiator support seal? Is that supposed to be installed on a J7?
 
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