What temp does your 3.0 run at?

[Odyssey 4x4]

I have an 89 3.0 4x4 odyssey. I've installed basically an entire new cooling system. This includes a new 3 core all metal CSF radiator, new hoses, new water pump, new Toyota red coolant, and new thermostat. Below are photos of my temp gauge after long (2+ hour) interstate cruises at 55-68 mph in cold weather climates (around 40-60 F), as well as when I am back in Florida (around 88-93 F). It has never overheated, but it gets hotter than i'd like to see. 

 

I'm considering adding a separate transmission cooler not only to cool the transmission better, but to also help the CSF radiator hopefully get my summer engine temps down a bit lower by not having to cool the tranny as well as engine coolant. 

 

[extech]

factory temp gauges are notoriously inaccurate.  before making any changes i would verify the actual temps with a mechanical gauge 

[MaineJed]

Most all my 94 and older Toyotas run like the bottom pic shows

[IdahoDoug]

I am with Extech, and used to be a product developer for both General Motors, and Lexus.  Factory guages are designed to provide heavily damped information on the engine.  If they were exactly accurate, they'd be moving constantly with RPM, engine load, outside temps, and other variables and owners would freak out - increasing warranty issues and service inquiries, etc.  So, long ago automakers dumbed them down.  Add in a few decades of aging connections, sensors, wiring and chassis grounds, and you can see why Extech's recommending checking it with a mechanical guage to get the real story.

 

It sounds like you did a beautiful job protecting your engine with that wise cooling system replacement.  Now find out what your actual operating temps are before making further decisions.  And nice job ignoring how all the "cool kids" are switching their vehicles to electric fans.  That is nearly always a downgrade in cooling versus a powerful engine fan from the factory.

 

One final comment would be to consider getting a new fan clutch.  Double check to confirm, but you likely have a viscous fan clutch, which after 25 years is a worthy refresh item.   If you do some research, Toyota often has a heavy duty version for hot weather markets for their trucks and SUVs.  I have these on both of my 80 series LandCruisers, for example.  If available, these are a bombproof way to upgrade your factory cooling system's capacity.  Cheers.

[Odyssey 4x4]

6 hours ago, IdahoDoug said:

I am with Extech, and used to be a product developer for both General Motors, and Lexus.  Factory guages are designed to provide heavily damped information on the engine.  If they were exactly accurate, they'd be moving constantly with RPM, engine load, outside temps, and other variables and owners would freak out - increasing warranty issues and service inquiries, etc.  So, long ago automakers dumbed them down.  Add in a few decades of aging connections, sensors, wiring and chassis grounds, and you can see why Extech's recommending checking it with a mechanical guage to get the real story.

 

It sounds like you did a beautiful job protecting your engine with that wise cooling system replacement.  Now find out what your actual operating temps are before making further decisions.  And nice job ignoring how all the "cool kids" are switching their vehicles to electric fans.  That is nearly always a downgrade in cooling versus a powerful engine fan from the factory.

 

One final comment would be to consider getting a new fan clutch.  Double check to confirm, but you likely have a viscous fan clutch, which after 25 years is a worthy refresh item.   If you do some research, Toyota often has a heavy duty version for hot weather markets for their trucks and SUVs.  I have these on both of my 80 series LandCruisers, for example.  If available, these are a bombproof way to upgrade your factory cooling system's capacity.  Cheers.

 

Thanks for the tip. I believe I did put a new fan clutch as well but it sounds like a wise choice to go with a heavy duty. I see one on rock auto made by US Motor Works (part number 22076). I’ll do some more research on a toyota made HD clutch, I always try to stay oem on engine parts if I can. 

[linda s]

Heavy duty Toyota fan clutch. 

https://www.toyotapartsdeal.com/oem/toyota~coupling~assy~fluid~16210-65020.html?vin=&make=Toyota&model=Pickup&year=1991&submodel=2 Wheel Drive&extra1=&extra2=&filter=(d=USA;1=3VZE;4=STD;5=ATM;6=4HC;7=RCB;8=WT;9=HLF;11=EFI;13=IV6;14=T1;0=VZN95L-TWSREA6)

Shows it fitting the heavy duty dual wheel models and also comes up for your 4x4. 

This site is for part numbers only. I'm sure you can find it elsewhere. 

Linda S

[IdahoDoug]

Nice, Linda. Yes get the hd factory. What they do is simply add higher viscosity silicone fluid. This makes the fan engage more aggressively. On the Cruiser the standard clutch is green, the hd is blue. Wouldnt surprise me to see that pattern corporate wide.  I have opened a couple viscous couplings and replaced the fluid with thicker from a lab in NJ and it works, but is actually quite tricky to get right.  There is a very precise amount in there and a corresponding very precise airspace as well to allow for a specific internal PSI when hot which aids operation.  Not recommended for a home brew on such a critical component! 

[Odyssey 4x4]

1 hour ago, linda s said:

Heavy duty Toyota fan clutch. 

https://www.toyotapartsdeal.com/oem/toyota~coupling~assy~fluid~16210-65020.html?vin=&make=Toyota&model=Pickup&year=1991&submodel=2 Wheel Drive&extra1=&extra2=&filter=(d=USA;1=3VZE;4=STD;5=ATM;6=4HC;7=RCB;8=WT;9=HLF;11=EFI;13=IV6;14=T1;0=VZN95L-TWSREA6)

Shows it fitting the heavy duty dual wheel models and also comes up for your 4x4. 

This site is for part numbers only. I'm sure you can find it elsewhere. 

Linda S

 

Linda comes through as always, thanks! I’ve read that some oem fan blades aren’t meant for the higher rpm that a HD clutch would bring, any thoughts? 

[linda s]

If you replaced your fan with OEM then it shouldn't be a problem. I will check fans too

Linda

[linda s]

This fan also comes up for your 4x4 and the heavy duty dual wheel model. Not an open blade fan

https://www.toyotapartsdeal.com/oem/toyota~fan~16361-65010.html?vin=&make=Toyota&model=Pickup&year=1991&submodel=4 Wheel Drive&extra1=&extra2=&filter=()

Linda

[IdahoDoug]

On the concern about fans and the HD clutch, not a problem.  The non-HD fan clutch is driven by the engine and locks up 100% to engine speed.  So does the HD fan, but it locks up at a lower temp, and stays locked longer.  So, same RPM fan speed.  Good question.

[Odyssey 4x4]

6 hours ago, IdahoDoug said:

On the concern about fans and the HD clutch, not a problem.  The non-HD fan clutch is driven by the engine and locks up 100% to engine speed.  So does the HD fan, but it locks up at a lower temp, and stays locked longer.  So, same RPM fan speed.  Good question.

 

hmm interesting. All of the comparisons i’ve read about standard vs hd vs extreme duty fan clutches state that they lock to different percentages of the engines rpm. 

 

 

Regardless, i’m not sure i’ve ever come across a fan clutch on any of my vehicles that is engaged at interstate speeds. Typically they’re just engaged at low speeds and idles, while interstate speed usually adequately cools the motor. 

 

[IdahoDoug]

Thanks for that. Hmm will have to recheck my assumptions, which are dated now. Perhaps engineers refined these clutches for better power/emissions. For instance perhaps fan blades are more aggressive, thus can achieve max cooling at lower rpm and they found this more efficient? Would be a great conversation around a campfire some day when I get the Sunrader finished.

[Scott iv]

On my 22re my fan cycles on and off even at freeway speeds. Though my temp gauge does not go up much past 1/4 ever. 

[Odyssey 4x4]

3 hours ago, IdahoDoug said:

Thanks for that. Hmm will have to recheck my assumptions, which are dated now. Perhaps engineers refined these clutches for better power/emissions. For instance perhaps fan blades are more aggressive, thus can achieve max cooling at lower rpm and they found this more efficient? Would be a great conversation around a campfire some day when I get the Sunrader finished.

 

You may still be right, perhaps older tech is different than the modern stuff. I’m not sure if the fan spins at a 1:1 ratio with engine rpm on these old toyotas, but I have seen people saying both things on the internet (HD clutch makes it come on more often / lower temp, in comparison to hd clutch spinning the fan at a higher rpm when engaged). Maybe someone more knowledgeable on the subject will chime in. 

[Odyssey 4x4]

22 hours ago, IdahoDoug said:

Thanks for that. Hmm will have to recheck my assumptions, which are dated now. Perhaps engineers refined these clutches for better power/emissions. For instance perhaps fan blades are more aggressive, thus can achieve max cooling at lower rpm and they found this more efficient? Would be a great conversation around a campfire some day when I get the Sunrader finished.

 

In this fan clutch diagnostic video on a toyota 3.4, he does a test on his clutch to see if he's able to get the fan to stop spinning with a piece of paper against the blades while running. This would make me think that the fan does not spin at a 1:1 ratio and different duty clutches may indeed spin the fan at different RPMs.