New OEM fan clutch but still roaring dump truck? (1 Viewer)

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Your thread focuses on several factors:

MPG issue is related to bigger wheels, heavy front bumper etc., I am fully stock 265/75/16 (38 PSI), stock bumpers and I get 16 to 18 MPG on highway.

I have a brand new Radiator (Denso), fan blade (AISIN), fan bracket (OEM) and fan clutch (AISIN): On cold start I hear the fan spinning but it is never loud: If I let idle for about 5-7 minutes, I hear the clutch engaging by roaring sound. When I drive off at cold or after warming up, I never hear the sound inside the cabin.

When cold, I can spin the blade about 1-2 blades. If you pull harder, I may get to 3 blades.
HAve you clean the AC and radiator fins?
 
Your thread focuses on several factors:

MPG issue is related to bigger wheels, heavy front bumper etc., I am fully stock 265/75/16 (38 PSI), stock bumpers and I get 16 to 18 MPG on highway.

I have a brand new Radiator (Denso), fan blade (AISIN), fan bracket (OEM) and fan clutch (AISIN): On cold start I hear the fan spinning but it is never loud: If I let idle for about 5-7 minutes, I hear the clutch engaging by roaring sound. When I drive off at cold or after warming up, I never hear the sound inside the cabin.

When cold, I can spin the blade about 1-2 blades. If you pull harder, I may get to 3 blades.
HAve you clean the AC and radiator fins?
The only reasons I mentioned several issues are because:

1. A locked up fan clutch is supposedly adversely affects mpg and engine power

2. Someone in a different thread had mentioned that after changing his fan clutch, his perceived transmission issues were gone too. I wanted to post about the transmission issue in a separate thread but didn’t know whether a locked up fan clutch which causes loss of power would cause perceived transmission shifting issues.

3. I do hear loud roaring in the cabin after driving a few minutes. Like I said, none of the other vehicles I’ve owned, including the one that had the same exact engine and transmission, ever sounded like a dump truck, in az summer heat.

It seems it’s common consensus that the dump truck like roaring is caused by a locked up fan clutch. I was baffled by the fact that changing out the fan clutch did not solve the problem and therefore wanted to see whether there’s any other insight.
 
The only reasons I mentioned several issues are because:

1. A locked up fan clutch is supposedly adversely affects mpg and engine power

2. Someone in a different thread had mentioned that after changing his fan clutch, his perceived transmission issues were gone too. I wanted to post about the transmission issue in a separate thread but didn’t know whether a locked up fan clutch which causes loss of power would cause perceived transmission shifting issues.

3. I do hear loud roaring in the cabin after driving a few minutes. Like I said, none of the other vehicles I’ve owned, including the one that had the same exact engine and transmission, ever sounded like a dump truck, in az summer heat.

It seems it’s common consensus that the dump truck like roaring is caused by a locked up fan clutch. I was baffled by the fact that changing out the fan clutch did not solve the problem and therefore wanted to see whether there’s any other insight.
This may sound simple, have you clean the radiator/AC condenser/Trans cooler fins? If you place a work lamp inside the engine bay, next to the fan, can you see it from the front of the LC? Must be able to see light even though the trans cooler. LIke I said, my fan clutch also soins like yours, but does not sound too loud.

The 4R with V8 has a smaller radiator and possibly a smaller fan/blade.
 
My 2006 lc has always been loud on startup and and I too replaced the fan clutch which didn’t make any difference.

I forget how many rpms it revs to on cold startup but it quiets down after a couple three minutes.

I have a coworker with a 2007 lexus 100 and his doesnt roar like my 2006 - both vvti but there is obviously a noise diff on cold start.
Should be around 1000-1200 rpm cold start. Will keep dropping in seconds.
 
You think you'll be able to capture the sound with your phone while driving?
First one after the cool morning 12-mile commute today just pulled into the garage at work. I rolled the DS front window down to get a better recording of the roar as I went above 2000 rpm while parked.



Second one leaving work late afternoon a few minutes after starting driving. No roaring. Everything was quiet.



Last one when I got home after the 12-mile commute back - fan roaring. All windows were rolled up. Today’s high was a mere 98 - really cool for AZ summer.

Fan clutch roaring after 12-mile commute back home with a cool high temp of only 98 in AZ

Fan clutch roaring after 12-mile commute back home with a cool high temp of only 98 in AZ - https://vimeo.com/751923717
 
First one after the cool morning 12-mile commute today just pulled into the garage at work. I rolled the DS front window down to get a better recording of the roar as I went above 2000 rpm while parked.



Second one leaving work late afternoon a few minutes after starting driving. No roaring. Everything was quiet.



Last one when I got home after the 12-mile commute back - fan roaring. All windows were rolled up. Today’s high was a mere 98 - really cool for AZ summer.

Fan clutch roaring after 12-mile commute back home with a cool high temp of only 98 in AZ

Fan clutch roaring after 12-mile commute back home with a cool high temp of only 98 in AZ - https://vimeo.com/751923717

Oh wow. So it looks like you get that “dump truck” noise when the engine is heated up?

What’s weird is, for me it’s been the opposite. I’ll get the loud fan at start up but once it’s warmed up for 1-2 mins, it goes quiet again while driving or revving as you did.
 
Pull the fan and clutch off and drive it around. That'll tell you if it's the fan/clutch combo or something else.

Jim
 
A quick update - as part of timing belt and water pump replacement, I had another Toyota OEM fan clutch and a new AISIN fan pulley bracket put in, along with new belts, idlers, tensioners, thermostat, etc. Fan still gets stuck and does not disengage. Still sounds like a dump truck or jet engine, causing loss engine power, extra unnecessary load on engine, hit on MPG, and annoying noise. Anyone having similar problems? Or any ideas?
 
Fluid Clutch engages, when coil on face gets hot. Heat is transferred from radiator to coil. What is ECT (engine coolant temperature.)?

Never mind. I asked this before and for other data point. You never responded. Good luck!
 
A quick update - as part of timing belt and water pump replacement, I had another Toyota OEM fan clutch and a new AISIN fan pulley bracket put in, along with new belts, idlers, tensioners, thermostat, etc. Fan still gets stuck and does not disengage. Still sounds like a dump truck or jet engine, causing loss engine power, extra unnecessary load on engine, hit on MPG, and annoying noise. Anyone having similar problems? Or any ideas?
What color is the fan clutch and part number?
 
What color is the fan clutch and part number?
Toyota OEM - silver color with the other side of the mating surface to the pulley bracket being black (not blue that is talked a lot about on this forum). Same as the Lexus OEM taken out. Part number 16210-50102.
 
Fluid Clutch engages, when coil on face gets hot. Heat is transferred from radiator to coil. What is ECT (engine coolant temperature.)?

Never mind. I asked this before and for other data point. You never responded. Good luck!
Thanks for posting a wealth of info in one of your previous posts. I said I might get a BT ELM327 ODBII adapter to monitor temps since the old laptop I run Tech Stream on has to be plugged in due to almost dead battery. Came to find out later that the one I ordered would not work with IOS, but I did end up getting another one that works with IOS via wifi. Been monitoring coolant and ATF temps the last couple of days during different times of the day. All stats were from driving around town. Early morning OAT 80, a bit after cold start coolant 185, ATF 110; driving around coolant 190-193, ATF 140-145; late morning OAT 90-95, coolant 194-200, ATF 153-161; late afternoon/early evening OAT 107-109, a bit after cold start coolant 195, ATF 142; driving around coolant 199-206, ATF 160-170. Planning on cleaning the coolers and radiator next week.
 
Your temps look fine.
 
Your temps look fine.
When should one start to worry? I've read all the threads of everyone's average, even during summer, but couldn't seem to find a "when to be concerned" number. I know there's variables but looking for a threshold number. I'm ok with my coolant between 188-195 (198 idling with ac) but trans is where Im lost. I feel like 160-175 in stop and go is too high, when 125-145 is cruising. Someone said the 100 Series A343F runs cool, but I'm not exactly sure what cool is.
 
When should one start to worry? I've read all the threads of everyone's average, even during summer, but couldn't seem to find a "when to be concerned" number. I know there's variables but looking for a threshold number. I'm ok with my coolant between 188-195 (198 idling with ac) but trans is where Im lost. I feel like 160-175 in stop and go is too high, when 125-145 is cruising. Someone said the 100 Series A343F runs cool, but I'm not exactly sure what cool is.
Stop and go and low speed will give you higher temps. Also, if you downshifted at highway speed your trans temp will go up. Absolutely normal. Trans is working harder and less airflow.
 
So any other thoughts on why the fan clutch wouldn’t disengage? I asked another local guy who has an 05 and his truck doesn’t do this. I know the heat is crazy here.
 
Going into 200F ECT is high. But then I DO NOT drive in OAT of 107F. Make sure your radiator fins and clean.

If your fan clutch never disengages, it must be defective.

I'd test like this. Start cold engine, fan clutch should be engaged. After about 2 minutes it should disengage, If not it bad.
 
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Going into 200F ECT is high. But then I drive in OAT of 107F. Make sure your radiator fins and clean.

If your fan clutch never disengages, it must be defective.

I'd test like this. Start cold engine, fan clutch should be engaged. After about 2 minutes it should disengage, If not it bad.
Thanks for the input. Will clean the coolers and radiator fins later this week. Will also test the fan clutch as you suggested.

when the engine is in operating temps, holding the RPM at steady 3,000 for a long while would cause the fan clutch to disengage after coming on for a while, wouldn’t it? When we tried that, it would not disengage, FWIW. What are the chances of two new OEM fan clutches being both bad - one from Lexus, one from Toyota?

Any other possibilities? I’ve seen it being mentioned in a video not specially for land cruisers or LXs that when the coolant temp sensor goes bad, there’s a possibility where the fan clutch would not disengage, although the norm is that it would cause the fan clutch to NOT engage which would lead engine to overheat. Anyone has experience with that? If so, is there a way to test it? I seem to remember reading in a thread that the sensor is located in a different spot in 06 and 07 model years?

Thanks again for your input.
 

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