LittleCaesar
New member
The optimal working coolant temp range should be 188-195F.
Overheating w/ AC on in PHX
- Thread starter tomato_racing
- Start date
bc4runner2017
New member
if the fan clutch is the issue would the fan still be running when i am idle? cause the fan runs fine when i am idling. apologies if this is an ignorant question but I know little of engine goings ons.
i am having this issue described in this old thread and trying to find out what it is.
thanks for any help,
mike
Hey Durk
So what are you saying here, with a dead FC, the fan spins more slowly than it normally would?
Sent from my LGMS428 using Tapatalk
The fan always spins.
It spins faster and much louder for a bit on the first startup of the day
and then when it's needed for extra cooling.
TheDurk
Elite Member
They can fail in two ways. They can lock up full-time and waste gas and rob power. Or fail to lock up when they should and spin weakly, causing the engine to overheat in stopped/slow traffic or slow offroading. My engine almost exploded in the line to the Lincoln Tunnel a few summers ago, but it was fine when I turned around and got back up to speed.
From his last post, though, sounds like his is working. The famous newspaper test can remove all doubt. If the engine is fully hot, and you can stop the fan with a rolled-up newspaper at idle, it's bad. Be careful, obviously.
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Ok cool. So the fan spins on its own because of the connection to the water pump pulley/etc, right? But then the fan clutch connects and makes it spin even faster as it detects a warmer engine environment?
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TheDurk
Elite Member
Close. When things are cool it declutches and spins slower but it still spins. As things heat up, a spiral thermospring closes a valve which engages the clutch making it spin faster up to the point where it locks up to the pulley that drives it.
I replaced my fan clutch (and the fan) recently and now the engine is running a whopping 2 degrees cooler!
I wonder if your thermostat is set at 6 or 12 oclock on the jiggle valve. It can make a difference.
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Thank you sir!
Sounds like without a working fan clutch, the existing 'spin' mechanism between the fan and the water pump pulley is not that useful.
To me, if it was useful, you wouldn't overheat at idle/traffic when FC is dead
LittleCaesar
New member
Thank you sir!
Sounds like without a working fan clutch, the existing 'spin' mechanism between the fan and the water pump pulley is not that useful.
To me, if it was useful, you wouldn't overheat at idle/traffic when FC is dead
The fan clutch dies a death and ends up either locked or unlocked as [MENTION=10169]TheDurk[/MENTION] said. If the former happens your engine stays cool but your 4runner is constantly roaring and your gas mileage is abysmal and that is putting it mildly. If is dies unlocked the 4runner has the potential to overheat quickly since the coolant in the radiator isn't being cooled as well (lack of airflow) as when the fan clutch is working.
Today in the world of crappy aftermarket parts I have seen many fan clutches dead out of the box, even from big name brands such as Hayden and Four Seasons. I replaced a fan clutch for a neighbor's kid on his Dodge truck this past Sunday and it took us four trips to the parts store to get one that worked correctly. If a fan clutch dies in the 4runner, buy Aisin.
willie2323
New member
my 99 has been in phx for the past many years (original owner in Prescott I got it with 42xxx on the clock, it has 126xxx on the clock now) and no hint of overheating but then I have never had any issues with it at all. gauge always is just below mid point.
good luck amigo,
willie
good luck amigo,
willie
That's the beauty of T4R -- We have part #'s for basically everything OEM unless it's something you can go aftermarket on and won't matter (lights, wipers, etc).
thegipper
New member
Well done Tim.
My coolant temps pretty much mirror your's exactly. Normally sits around 190 but if I'm stopped with the AC on it climbs up to 194/196 or maybe even higher if its real hot out.
My radiator is 2 years old (Denso)
Radiator cap is OEM and 2 years old
I did a complete coolant flush two weeks ago (5 flush total), OEM coolant diluted to 50/50 with distilled water
Brand new OEM thermostat/gasket
My fan clutch is original and worked exactly like yours
I was thinking of buying a new fan clutch but after seeing your video, I doubt it will change anything. Some guys on here say they never go above 190 degrees even when off roading with the AC on in hot areas. I just don't know how that is possible.
My water pump is the only other variable in this equation. It is due to be changed soon.
For now, it's not that big of deal. It also doesn't usually get that hot here in Wisconsin.
JayRolla
New member
There it's absolutely nothing wrong with your cooling system. It's working as designed and those are normal temps.
mtbtim
Elite Member
Yeah, I call bullshit for those that say they never go above 190. Just driving around town I go above 190. When I'm traveling loaded down with gear and climbing grades, I'll go into the high 190's if it's really hot where I'm at. The only way I can see people not going above 190 is if they have a lower temp thermostat than stock installed and that would mean under normal driving conditions they're running around in the low 180's. Every 3rd Gen I've worked on and took a look at the coolant temps runs around the temps we're seeing.
The only reason I'd change the fan clutch is for peace of mind if you're taking a long trip out into the Boonies. If everything else in your cooling system is newer, why not spend $100 for a new fan clutch. It might not change your coolant temps, but at least you'll feel better about it on long road trips and won't be kicking yourself if it dies on you and causes you to break down. If it were me, I'd replace it.
Now, if you were asking if you should drop $5000 on suspension components for a rig that you sometimes drive on a fire road a passenger car could handle, I'd say you're wasting money. But, then you wouldn't look totally cool driving around the mall parking lot and also a King or Icon suspension system will help you not spill your latte while negotiating those mall parking lot speed bumps.
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DK327
Member
Yep, it's in 6pm position. I usually get 188-193F prior to replacing the fan and clutch, now it's 186-191F. Small difference but it was time to replace it after 242K miles and every little bit helps!
Toyota engineering ftw.
