A Great Debate: To Fix Or Not To Fix (Fan Clutch)

[reffug]

Turbo,

I'm with the thinktank waterboy on this one. His opinions and recommendations have been proven time and again to be spot on.

 

[landtank]

The FSM for the 2006 LC and Tundra shows the same valve opening temp as my 97 manual shows... 176 to 183 F, valve lift 0.39" at 203 F.

Not sure if that exactly answers your questions, but might.


Rookie2

Thanks it does. It would seem to me that if higher operating temps where desirable then Toyota would have definitely implemented that in the current design.

I realise this is a debate, but I can't help feeling an argument coming.

I'll leave it here with this thought.

With the exception of a few extreme weeks during the summer my truck ran at normal operating temps. Last year I had an oil analysis done and posted it up on BOBISTHEOILGUY.com. It was a 15k test of the new M1 extended oil and comments such as "the best one we've ever seen" and "this guys engine will last forever" where among the responses.

How allowing my engine to run hot will improve on that I don't know, but I have no ambition to find out.

 

[CJF]

LT:
We disagree on this point. 13 years ago 180-195 temps off an engine driven fan were considered minimally compromising.

Since that time, research has shown that temps of 100C are more optimal, mostly for moisture release in the oil. Since that time, formulations of gasoline, oils and viscosity have targetted that temperature. It is also more ideal in terms of engine wear.

100C is also well within the operating environment of the engine, as Mr. T doesn't cut A/C until 226F (His definition of getting too hot).

I believe the post that 108F is a good temperature for the 80 engine.

We also know it's much more difficult to control engine temps with a VC mechanical fan. A lot of variables specific to a truck, it's airflow affecting mods, it's wear and it's condition that probably dictate that cooler is a better compromise for an engine driven fan. One of the main reasons for on/off mechanical fan couplers and electrics. They are engine temp driven, not fan thermostat environment driven.

My .02

Scott Justusson

Are there higher temp. t-stats available for an FZJ? And if so, would you put one in your rig?

Curtis

 

[alkaline747trio]

Turbo, do you still have the factory tranny cooler with a supplementary cooler, or just a larger cooler? Either way, where do you have it mounted?

 

[SUMOTOY]

Are there higher temp. t-stats available for an FZJ? And if so, would you put one in your rig?

Curtis

Low Banana Answer (LBA): Don't know yet, but I don't think it's necessary. More accurate control of the radiator fan intervention would be my primary preference. The stock thermostat certainly kept me warm enough at really low temps this year at Steamboat, so I see no real need to change it.
-----
Higher Banana Answer (HBA): I presume there to be a few Tstats to choose from, but not sure it's the first thing I'd change, or if I'd change it at all. What normally controls the engine temp over the Tstat temp is the radiator fan. I'd want a fully open thermostat a few degrees shy of 212f, and a method of controlling rad fan intervention above that.

Most modern Tstat applications I'm aware of (all exceptions already noted) for a production engine setup regardless of fans uses 80C (175f) or 87C (190f) thermostats. Toyota has a 78, and some race motors use 70C ones, but the most common are 80 and 87. What you are looking for is a thermostat fully open at maybe ~107f and and generating enough heat to keep you warm in the winter.

To me the thermostat only needs to be open so that the fan isn't fighting the thermostat or vice versa. BTST many times. The fan should lockup/startup within a couple degrees over fully open thermostat temps = 212f.

Since we are dealing with a slow reacting thermostat and a fan thermo that uses ambient temp, not engine temp, there is definitely some slop in these numbers as Mr. T. chose them.
----

LBA/HBA =There is also absolutely no reason to think a FJ80 Toyota motor service life is at all compromised by 100% duty cycle at 212F. We do know piston wall wear is less, fuel consumption is less, and A/C function is fully active.

Scott Justusson

 

[turbocruiser]

Turbo, do you still have the factory tranny cooler with a supplementary cooler, or just a larger cooler? Either way, where do you have it mounted?

Just a much larger cooler. It is mounted below my ARB bullbar in the interior recess with a rubber air damn to direct air through the thing. I've always thought that the cooling capacity of the thing is two to three times that of the stock setup. Here's one photo.

 

[Romer]

LT:
We disagree on this point. 13 years ago 180-195 temps off an engine driven fan were considered minimally compromising.

Since that time, research has shown that temps of 100C are more optimal, mostly for moisture release in the oil. Since that time, formulations of gasoline, oils and viscosity have targetted that temperature. It is also more ideal in terms of engine wear.

100C is also well within the operating environment of the engine, as Mr. T doesn't cut A/C until 226F (His definition of getting too hot).

I believe the post that 108F is a good temperature for the 80 engine.

We also know it's much more difficult to control engine temps with a VC mechanical fan. A lot of variables specific to a truck, it's airflow affecting mods, it's wear and it's condition that probably dictate that cooler is a better compromise for an engine driven fan. One of the main reasons for on/off mechanical fan couplers and electrics. They are engine temp driven, not fan thermostat environment driven.

My .02

Scott Justusson

Your mixing Cdeg and F deg in the same post Don't see where the 108 deg F came from.

BTW - I purchased an onboard scanner today with real tim data sensing. I had the opportunity to test it on two trucks in the same conditions.

Both trucks have the 94 Brass Rad
Both Trucks running Toyota Red and recently flushed
Both trucks recently replaced Tstats.
e.g., both trucks cooling systems are in top shape.

Outside temp 80 deg - Data below is from the OBDII port in real time mode.

Truck 1 - Sarah's basically stock LX450
Once truck in operating range Coolent temp averaged between 190-195 deg F. Intake fron 128 to 138 deg F. Higher temps seen at stops and idling periods

Truck 2 - My LX450 - Dual Batts, with 1 tray cut. Once truck in operating range Coolent temp averaged between 188-194 deg F. Intake from 129 to 136 deg F. Higher temps seen at stops and idling periods.

The deltas are so close as I could say they perform equivelantly in 80 deg weather. I will try and do this again on a hot day and then after the supercharger on my truck for comparison.

 

[L8Shift]

If it ain't broke... you're not driving the LC hard enuff! (sorry )

The FSM p. EG222, Coolant Temp.; Measurement Item - Engine coolant temp sensor value; Normal Condition, After Warm UP: 80 ~ 95C (176 ~ 203F).

*Normal Condition - Idling, N or Park, a/c and all access switches are off.

Do the newer full size trucks have computer assisted cooling?
Could the oil stand operating ~h20 boiling point?

~~
I recently installed the Hayden fan clutch and have Not recorded temps much higher then the above on the scan tool these past 90+ degree days.. the a/c didn't cut out like before either..

 

[Tools R Us]

I don't see the need for a "great debate" and doubt that will ever be or needs to be a consensus. If your system is working to your satisfaction, leave it alone and drive, if you feel that you can or need to upgrade it, do it, if you feel that you need to have control of every bleeding function, rip it all out and redesign it.

For me the stock system worked well most of the time, in very hot weather the A/C vent temp would fluctuate more than I like and when pushed hard on the trail I had an off idle ping. By simply changing the clutch fluid to a higher viscosity both of those problems disappeared and I have much higher volume and cooler underhood airflow.

So for a couple of hours of my time, a few bucks worth of fluid I feel that I have improved the capabilities of the system, making it more robust and it's completely reversible by simply changing back to the original fluid. It works so well on my truck, for how I drive it that if I needed a new clutch today, I would order a blue hub and a couple of tubes of 10000 cst fluid, suck out some of the original and add the new for about 8000 cst before it was installed.

 

[turbocruiser]

So TRU, what fluid DID you use, I cannot remember right. Yer sayin ya just drained and filled and did not do the timing adjustment at all, is that right? Thanks.

 

[Tools R Us]

So TRU, what fluid DID you use, I cannot remember right. Yer sayin ya just drained and filled and did not do the timing adjustment at all, is that right? Thanks.

Correct, I drained, cleaned and refilled with 10000 cst. IMHO it's thicker than necessary, if I were to do it again would shoot for 8000 cst. Rick did 5000 cst and says he wishes for a little more, that's where we stand on the testing at this point. My thought is if you are in a cooler area and don't push your truck hard 5-6000 cst will work well, if your truck is run hard and/or in a hot area 7-8000 cst would be better.

If your clutch is good there is no need for the clean out step, the fluids mix. Say you want 6-7000 cst, remove 20 ml of the stock 3000 cst fluid and add two tubes of 10000 cst from C-Dan and screw it back together. It's a simple mod that makes a big difference.

 

[landtank]

When adding oil be aware of the level of it in the clutch. Depending on how much oil is removed, 2 tubes could be more than what's needed. I'll be modifying a clutch for another member soon and am going to try using a heat gun to aid in the removal of the oil. Basically while the clutch is held on it's side, I'll be blowing hot air into it to loosen the oil and blow it out some.

 

[SUMOTOY]

Your mixing Cdeg and F deg in the same post Don't see where the 108 deg F came from.

Thanks, it was 208f, and I made the edit. I tend to use C around my shop, it appears most here use F. It will take me a while to fully accomodate that switch.

Truck 1 - Sarah's basically stock LX450
Once truck in operating range Coolent temp averaged between 190-195 deg F. Intake fron 128 to 138 deg F. Higher temps seen at stops and idling periods

Truck 2 - My LX450 - Dual Batts, with 1 tray cut. Once truck in operating range Coolent temp averaged between 188-194 deg F. Intake from 129 to 136 deg F. Higher temps seen at stops and idling periods.

The deltas are so close as I could say they perform equivelantly in 80 deg weather. I will try and do this again on a hot day and then after the supercharger on my truck for comparison.

Good data, please log a lot before the SC Ken. I'd also be very curious what those intake temps look like with the SC install. Ken, where is the IAT located on your truck now?


SJ

 

[SUMOTOY]

If it ain't broke... you're not driving the LC hard enuff!

Thanks I found that out

Do the newer full size trucks have computer assisted cooling?
Could the oil stand operating ~h20 boiling point?

1)Some do, more are. Price of gas goes up, all will.
2) LBA: Yes, it's designed to.
HBA: The viscosity rating of oil is at 0C (32F) for the first number and 100C (212) for the second number. Extreme heat of oil is defined as 150C (300f). Many (if not most) of the oil additives address moisture buildup which causes sludge and viscosity breakdown.

SJ

 

[SUMOTOY]

Shroud Time Romer

Hey Ken:
Now that you have datalogging capabilities, how bout removing the fan shroud and logging some temp data

SJ

 

[Romer]

Ken, where is the IAT located on your truck now?

SJ

Not sure, where ever Mr. Toyota put it Guess I could look in the FSM when I get home.

I'll see what I can do about the shroud. Not a lot of free time this week.