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

what could the culprit be?

perhaps a worn needing replaced compressor
maybe a worn ac idler

driving 6 hours with the AC on with minimal stop and go the other day

got back into the city and turned the ac OFF, feeling sluggish no pep
stopped for taco fuel, turned engine off, filled up, started up, left ac OFF
and the hp returned like nothing ever happened

whats going on here?
idk!

what other pieces may be doing this

 

Don’t know if this is related, but my A/C will briefly not blow cold under rapid acceleration...

 

it was blowing cold considering the temps and humidity it was tasked to handle

i rarely if ever have the AC on in stop and go city driving, that is what the windows open handles!

it just lost the pep this 3.4 is supposed to have, like it was dragging along all limp through the gears after i shut it down until the engine was turned off
the restart at the pump made it chipper again

 

you think that is the problem maybe? worn AC clutch
i have looked at it while idling but not sure what its doing under there while on the move at 20-40 mph

sauce was good with the discount, 140c

 

it had a problem last summer season with some awful grinding noise in each gear at certain RPMs (2.1k) after I shut the AC off and kept driving in the city traffic
that noise has not resurfaced this year so far
gremlins...

 

I would take the truck to a qualified A/C shop and get the A/C system thoroughly checked out. Should cost around $100 and take an hours but then you will know (if the mechanic is worth his salt) the condition of the compressor. The mechanic should recharge the system too during his checkout.

 

Sounds to me like the AC clutch might not be disengaging. You can watch it engaging and disengaging. When its disengaged the center part of the AC pulley will not appear to be spinning, but the belt will still be going around it. If you've been running the AC then turn it off, and it feels like its dragging, pull over and pop the hood, if the center of the AC clutch is spinning, your AC clutch is broke.

Its worth getting fixed soon, too. If the AC clutch isn't releasing, then the AC can't shut itself off on low or high pressure conditions. Which isn't good.

 

That is strange my AC is on all the time until things freeze again

Fan on High.

I never notice a lack of engine performance that extreme

Then I carry a lot of weight

Stop and go driving as well

Higher then normal pressure but not enough to seize the compressor if you have an electrical problem and it is not cycling like it should.

 

had a chat with the Toyota master mechanic at yesterdays appointment. He wasn't really sure what was going on from a verbal description and said sometimes these issues need to actually break to figure out what is going on. $891 estimate to replace denso A/C compressor with new refrigerant is big expenditure

the other mechanic in the shop hinted that it may just be the fan clutch wearing (part# 08921-04950)
it may not be losing hp but sure sounds like it if the fan is roaring louder than it usually does/should be as RPMs increase, i often shift gears from that sound instead of always looking at the tach out of habit

he said the use of A/C puts a load on the engine and warms it up quicker making fan work harder and louder

does that sound plausible? a new fan clutch would be much less output expenditure cost to start throwing parts at it

 

Humm the master Toyota tech just spat out a compressor change price ? the Denso compressor is pretty reliable and for the money wouldn't shotgun that change, as far as the A/C system goes have it checked out by a local shop that does A/C work not the dealership. The fan clutch is easy to check, with the engine cold and not running it should spin freely by hand or freewheel. When the engine is hot and not running (meaning just after shutdown) it should have resistance to rotation or may not move at all because its engaged. Also you could have an idler pulley bearing going bad, Im not as familiar with the V6 but would think that if one of these components (A/C compressor, idler pulley or A/C clutch) were going bad or locking up the belt would be squealing very loud. If the compressor is starting to fail or You have a bad cycling switch or a clogged expansion valve the A/C shop should be able to diagnose it quickly.
Good Luck.

 

i honestly do not understand what exactly causes the engine & fan (if thats what i am hearing) to 'roar and seem to strain' after turning the A/C button off (that has been on for many hours & miles on the highway) then getting into city stop and go driving, turning engine off to put some more juice in the tank, re-starting and its all back to normal!

i absolutely abhor porking out a friggn 'diagnostic check fee' when nothing is found to be operating improperly...
and the killer! is when those shops, after paying a 'diagnostic fee' and the problem is found, not having that 'diagnostic fee' subtracted from the repair total

certainly i understand that some shops do not want to diagnose something free of charge and then only to have you go elsewhere or diy if you can handle it

i asked for the compressor change quote just for my curiosity having no clue about it, its old and slightly weathered being down low

 

When the fan clutch locks in the do tend to roar more then when they are just coasting.

It has been so long I don`t really take notice I can`t recall if I ever changed mine

From the heat soak unless your city driving is enough cool down I would think the fan clutch would stay locked when stopping for gas

Is your engine getting old and tired that you seem to really notice the loss of power ??

 

without any A/C operation at all its quite chipper still, very much so
its even very chipper in the early morning with the A/C just being turned on once i hit the entrance ramp and everything is at operating temp

i tested the drain the A/C has on the engine and fuel consumption while just city stop/go driving
started with about 1/3 tank of fuel left and ran it to the point of needing a fillup, it lost nearly 20 miles on that tank or ~1mpg equivalent for the 1/3rd left
driving on the freeway exclusively with A/C on for the most part it does not appear to be sucking more fuel than normal so idk!


it may be a perceived 'loss of power' with just the fan (or whatever) roaring more than usually does between gear shifts with no A/C in operation, having just been turned off

 

Like I said I really don`t notice a difference .

Then a $100.00 in gas a day is common before prices came down

 

Your truck is pretty low miles for a compressor to go out,

My compressor went out at around 400,000

 

something just seems fishy and off!

 

Ok had the same issues again today after many long miles with AC on it lost its get up and go from a stop after turning ac switch off!

Got back and while engine running checked ac clutch and was not moving

Turned engine off and had the resistance in the fan like noted

What else to check next
What might be causing the fan road and sluggish feel?

 

If your fan clutch goes out and sounds like a lawn mower the engine will run with less power

 

should it not have so much resistance when hot, it was turning by hand with a little effort

are there bearings in there?

 

There is special fluid in there and a small thermostat coil that opens and closes.
When it’s hot out the clutch fan will lock to make the fan suck more air.

Something when these clutch fans go out they just spin and do not engage and other
times they lock up sounding like a lawn mover all the time