Tacoma Fan Coupling Clutch issue ? Loss of engine pep with AC sometimes

Also if your engine is running hot it will definitely run with less power,

You need a scanguage or something else to know your exact temperature.

The stock gauge doesn’t give you the exact temperatures unfortunately

 

Toyota made two different type fan clutches for our trucks.

If you look at the snout where the fan blade connects if it an OEM fan clutch
the tip will be painted orange or green.

Green is the heavy duty fan clutch
Orange is the standard fan clutch,

My truck came with the tow package so I have an OEM heavy duty green tipped fan clutch.

I’ve gone through 3 of these fan clutches in my truck

 

The earlier Tacoma had green or orange I believe, maybe later they changed, dont know,
The green ones come with the tow package. Stays engaged longer and may spin alittle faster I believe,

“the cooling fan is connected to a drive pulley via a clutch, which allows the fan to operate at different speeds according to changing conditions. This process reduces wear and tear on the engine and saves fuel overall by allowing the fan to run fast when the engine is hot and slow when the engine is cool. To operate the clutch, an automatic thermostatic spring regulates a valve that controls the flow of a silicone fluid between different chambers of the clutch assembly.”

 

Only if the fan clutch has not been changed several times already we are talking about 15 plus year old trucks

The OP your engine just might be getting tired so the AC the Alternator the locked fan clutch all reduce the response of the engine.

Compare how the fan clutch spins when cold after sitting 6 to 8 hours compared to a heat saturated engine .

Only on the Hottest day loaded and towing up a several mile hill 3rd gear and 90 degree temperature does my fan clutch lock up.

Might be my Copper brass 3 row radiator has a impact.

 

Fan Clutch, from what I recall the main component in the fan clutch is the Bi-metal spring, its not like a coil spring or valve spring its a flat metal band spring like in a kids windup toy except you don't windup this spring and its made up of two laminates of different metal. One end of the spring is connected to the outer fan hub the other end is connected to the inner drive hub pulley, the spring will tighten or loosen depending on temperature being blown at it from radiator. When engine is cool and you first start it up you will hear it roar for about 15-20 seconds that's because You (the engine) wound up the spring and its direct driving for a few seconds, once the spring stabilizes and unwinds it will lag behind engine rotation in a no load condition. When the spring gets hot it tightens up and goes almost 1:1 drive from pulley and puts a load on the engine and pulls air through radiator, hope this helps this my best understanding of it, as others have mentioned You may have an overheating problem, good luck sir.
Andy

 

this is the part i would be in need of?

08921-04950 - fan clutch

 

i can certainly test it out for a couple hours with no A/C on (windows down) for a sweatfest in 90+ humid temps
and see if the same thing happens with NO prior A/C load when i get back into stop and go traffic

 

oof, potential overheating does not sound good!
i have not noticed the gauge move much past 1/3 of the band

 

Jay
Don't know if You need a fan clutch or not, just trying to give some insight.
Andy

 

checked the cold engine fan turn by hand resistance and feels VERY MUCH the same effort to turn as last evenings hot engine off hand turn resistance, rotating it towards the washer fluid side

normal?
not normal?

 

Your the one spinning the fan if it feels the same cold or hot you should be able to tell.

As far as I know my Fan Clutch is still original along with the timing belt at 250,000

I am guessing you have the 3.4

 

Fan clutch check, get a sharpie mark one of the fan blades for reference a small piece of tape will work as well, on a stone cold engine (tomorrow morning) rotate the fan consistently using both hands without letting go of it, by the 3rd rotation you should encounter lots of resistance and may not get to 5, if you get to 5 rotations and no resistance the clutch is shot, hope this helps.
Andy

 

https://www.autoblog.com/2016/01/08/symptoms-of-a-bad-or-failing-fan-clutch/

 

Jay, this is the towing fan clutch

Timmy has a video on fan clutches on YouTube

 

Disregard what I said about fan clutches, I was right but I was wrong, I apologize,
I did not realize our Tacoma's had viscous drive fan clutches, assumed they were spring drive (old school), my truck only has 230,000 so I haven't had to change mine yet, would have figured it out then.
Thanks Parkvisitor for posting correct part and info, I learned something

 

so i don't need to try and twist the fan blade on a cold engine 3 to 5 revolutions to see what resistance there may or may not be?

 

from that topic...

3. Decrease in power, acceleration, and fuel efficiency
A decrease in performance is another symptom of a bad or failing fan clutch. A faulty fan clutch that leaves the fan permanently engaged will not only cause a noisy engine, but can also cause a decrease in performance. A stuck fan clutch will cause excessive, unnecessary drag on the engine, which can cause a drop in power, acceleration, and fuel efficiency, sometimes to a quite noticeable degree.

As the fan clutch is one of the main cooling system components, it is very important to the proper operation of the engine. When it fails, the engine can be put at risk of serious damage due to overheating. If your vehicle is displaying any of the symptoms above, or you suspect that your fan clutch may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the car will need a fan clutch replacement.

 

how the heck does one inspect this or just throw a new part at it

 

If the clutch has failed. It will typically fail either on or off. If it’s stuck on, you’ll always hear a roar from the fan. If it’s always off you won’t.
It’s normal for the fan to be loud for the first up to a minute when a cold engine is started. When your a/c is on your going to be pulling more heat towards the clutch from the condensor. So the fan will start to kick in more. By the sounds of it you have a functioning fan. This recent heat wave, my tundra and the 02 Tacoma both start roaring the fans to life with the a/c on. This is normal. And yes, it makes a noticeable difference in power.

 

drove 200 miles yesterday in the 100 degree heat with NO A/C on, it was miserable with the windows up!!
interstate, highway, small town stops and one train
had the same 'issues' when i had to stop and go in town, but not as pronounced as it had been with the A/C working lately under various conditions
i guess the A/C is not the culprit here idk
just a strange oddity