1HDT Radiator Viscous Fan Clutch, 80 Series Getting Hot

Post by **vSAHARAx** » Mon Jan 21, 2008 8:08 pm

Hey All

Just got home from a week at Fraser Island, all was sweet except the Cruiser keeps getting Hot Hot!!!!!

first trip i have done in this truck, So didnt know of any problems. I was towing a jet-ski and had a fair bit of gear in the back. The first time it got hot was going up the gateway bridge in 3rd gear at around 2800rpm because i was stuck behind a truck. I wasnt making it work hard (as in wasnt slugging it up the bridge, she still had a heap of grunt under her belt) but got to the top of the bridge and it was just above 3/4 on the guage. It took for ever for her to return to normal running temp. Continued this on every big hill. Yet i could put my foot to the floor while over taking and the gauge wouldnt budge. Could not put the AC on without it going right up under the red, reguardless of terrain. On the beach if i made it work, she would heat up. Had to drive up through the soft stuff for a few Km's just prior to reaching indian head, and 3 times i had to stop to let it cool down. I stopped and set the hand throttle to 1400 rpm and took a good 10 mins, for the gauge to come back to half way.

Im going to get the radiator flushed but everyone is saying my fan clutch is stuffed. It is easy to turn whether the motor is hot or cold and does have a bit of play. So at this stage i beleive the fan is 1 factor letting the cooling system down. But in saying that is the fan really doing anything when on the highway?

Should i buy a genuine fan clutch? or are aftermarket ones just as good? Roughly what price am i looking at?

Any advice or oppinions would be appreciated

Cheers Troy

Post by **BOGAN V8** » Mon Jan 21, 2008 8:38 pm

Dont know if this is going to help but i have a car at work at the moment that overheats when you give it some on a long hill its a farm car so have removed radiator and blown out all grass seeds and replaced but still doing the same..

So was told to replace the themostat and also remove the viscous coupling and pull it apart and add some more fluid to it ($10 from Toyota) so will be doing that tomz at work and i will let ya know how it goes..

Also this crusiers fan has same symptoms as yours so might be something to look at cheaper than a new fan..

Post by **vSAHARAx** » Mon Jan 21, 2008 9:32 pm

BOGAN V8 wrote: So was told to replace the themostat and also remove the viscous coupling and pull it apart and add some more fluid to it ($10 from Toyota) so will be doing that tomz at work and i will let ya know how it goes..

Also this crusiers fan has same symptoms as yours so might be something to look at cheaper than a new fan..

Yeah was going to replace the thermostat, as they are cheap as chips, I have thought about re-packing the oil, but i have noticed mine has a bit of play, the viscous moves on the hub a little. I figured if i replace the hub thats another thing i can cross off the list! Will be interesting to see what the radiator mob say about the core, as she lived at the gold coast for half her life, so i wonder if it will be just about shagged?

Post by **Suspension Stuff** » Mon Jan 21, 2008 10:26 pm

They go on about hot Cruisers here
http://www.offroad80s.com/viewtopic.php?t=873

Whatever the problem is, you are best off getting a pyrometer or some gadget to measure the temps.

Shane

Post by **scottmcguinness172** » Tue Jan 22, 2008 7:24 am

mate just buy anoither clutch for ur fan cause mine got warmish at high speed also have u checked ur head gasket?

Post by **scottmcguinness172** » Tue Jan 22, 2008 7:26 am

i can get aftermarket clutchs for about 100$ and it worked sweet on mine and i put a higher temp thermostat in mine

Tue Jan 22, 2008 10:38 am

Go to toyota, get 2 tubes of silicon fluid for fan clutch - about $10 ea. Take home, dissassemble and add to the clutch. Worked a treat on the surf.

If it's leaking / noisy this wont help.

Paul

Post by **vSAHARAx** » Tue Jan 22, 2008 3:00 pm

whats the quality difference between the Aftermarket and the Genuine Toyota clutches?

Post by **scottmcguinness172** » Tue Jan 22, 2008 3:21 pm

toyota one is probally 3x the price

Post by **me3@neuralfibre.com** » Tue Jan 22, 2008 3:27 pm

vSAHARAx wrote:whats the quality difference between the Aftermarket and the Genuine Toyota clutches?

There is some debate.

Toyota one is 3x the price.

I have tried both and neither cured my problem. I didn't find a significant difference between aftermarket and factory.

The NipponDenso (Toyota) one is possibly better quality.
It's the usual deal, you spend what you have to to try and track down the problem.

Paul

Post by **guzzla** » Tue Jan 22, 2008 5:04 pm

As mentioned above, there is no need to replace the clutch fan unless its cracked etc.

Just remove it from the vehicle and undo the screws holding it together.

Remove existing oil and replace with now oil purchased from your local toyota dealership, its in a small plastic packet and costs about $10.

As for your overheating it could be a multitude of things including...

Blocked internal cores restricting flow - this requires professional cleaning.

Bung thermostat - easy fix

Bung waterpump (most often the bearing starts to go ) - easy fix.

Not the correct ratio of anti freeze / boil - easy fix

I personally like to have my cooling system working 100% and recently had the whole lot replaced - rad 3yr wnty (as opposed to toyota 1 yr), cap, pump, thermostat new fluid in clutch and full system flush for $1400. Cheap insurance when im in the middle of nowhere and sound piece of mind over all.

Just gotta fit a quality temp gauge now as the factory unit has a massive flat spot in it to stop whide spread panic for those people who dont know correct opperating temp ranges. Only problem is by the time it has moved towards the red further damage is not too far away if not seen soon enough and rectified.

Post by **vSAHARAx** » Tue Jan 22, 2008 5:42 pm

how exactly do those clutches work, im going to re-oil it and see what happens, going to change the thermostat and get the radiator cleaned and checked, im one for doing it right the first time for peice of mind.

Post by **me3@neuralfibre.com** » Tue Jan 22, 2008 6:50 pm

vSAHARAx wrote:how exactly do those clutches work, im going to re-oil it and see what happens, going to change the thermostat and get the radiator cleaned and checked, im one for doing it right the first time for peice of mind.

The oil is silicon fluid, it "couples" the power through. There are several chambers in it with a valve. They rely on the centrifugal force to work, so you can't bench test them with a drill - I tried.

There is a bimetal spring on the front. As it heats, it rotates, turning a valve plate inside. Fluid is allowed to circulate to the coupling section, presto - it engages. When the valve closes the fluid is gradually pumped back to the centre and it uncouples.

The theory is simple. The actual fluid flow hurt my head and I gave up.

Paul

Post by **vSAHARAx** » Tue Jan 22, 2008 8:28 pm

do they wear out as such, or does replacing the oil basically re-condition them?

Post by **BOGAN V8** » Wed Jan 23, 2008 6:38 pm

Well we fixed the one at work today just added 2 tubes of the silicone to the viscous couple and replaced the themostat and hey presto no more getting hot..

Didnt remove any of the old fluid form the coupling just added 2 tubes and it now works...

Post by **Troopy93** » Wed Jan 23, 2008 7:14 pm

I just replaced the clutch fan on my Troopy with a Borg Warner unit off ebay, $119.90 delivered compared with $438.00 from Toyota. The ebay one has cured my once only overheating problem, so for me it was worth the cost of getting a new one and not having to worry about it for a couple of hundred thousand ks...

Post by **Troopy93** » Wed Jan 23, 2008 7:15 pm

oops double post

Post by **Surfin Alec** » Wed Jan 23, 2008 8:30 pm

Just been down this road myself. I firstly added 1.5 tubes of silicon oil to the existing oil but found that the fan clutch locked up too early and didnt unlock till the car was stopped for a while.

So I drained the oil overnight (its thich as and slow to drain) then added 1.5 bottles of oil as per my mate at Toyota's recomendation and it works fine now. Locks when it should and unlocks too.

Alec.

I also replaced the coolant and thermostat.

Post by **bigcam** » Thu Jan 24, 2008 8:19 am

my Bundy used to get hot when pulling up hills at any speed, then got progressively worse until the thermostat locked shut, so replaced that and was still getting hot when working hard, gauge on 120 degrees celcius. opened the bonnet and sopped the fan with a stick, undid the fan jammed a sheet of rubber in it bolted it back up, now 100% locked up and running sweet!. no more problems from that puppy. she only revs to about 4k so you cant even hear the fan, only problem will be when revving in water but ill cross that bridge when i come to it.

new fans are about 140 from ebay/bursons.

Post by **rockcrawler31** » Fri Jan 25, 2008 6:37 am

yeah some good advice on here and bad advice. Having had a 75x that had over heating problems i've gone through pretty much everything on a toyota's cooling system and know it backwards. Start with the cheap and easy stuff first

1. change fluid - $20-$30
2. Clean radiator fins AND air con fins thoroughly (you should be able to easily see through them) - Free
3. Thermostat - $20 bucks
4. Re oil fan clutch - $20 bucks
5. System pressure test and rad cap test - free if you ask nicely and a tenner for a rad cap

if these don't work then next to try is

5. have the rad core professionally rodded and cleaned Make sure you fit an inline filter to the inlet of the radiator hose when you refit and CHECK IT REGULARLY - $60-70 if you take out and give it to them saving the labour cost of removal and refit.
6. Test for compression gasses and bubbles in coolant (head gasket/head damage test) - free if you ask nicely or a tenner
7. Pump - 150 - 200 bucks if you remove and refit yourself. (make sure you learn how to reset timing for christ's sake)

After all of this if it still has drama's then i don't know. remember that no diesel likes to labour with full throttle as unburnt diesel will bring up your egts and over heat the motor in no time flat. This includes towing, sand work, and hills. It could just be driving style.

Post by **me3@neuralfibre.com** » Fri Jan 25, 2008 9:05 am

rockcrawler31 wrote:
After all of this if it still has drama's then i don't know. remember that no diesel likes to labour with full throttle as unburnt diesel will bring up your egts and over heat the motor in no time flat. This includes towing, sand work, and hills. It could just be driving style.

I find the last statement interesting.

So are you saying I shouldn't be able to hold 3/4 throttle and 680EGT's sustained going up the toowoomba range with the trailer?
Cause I can't, and I can't fix it (yet).
To my mind - flat throttle and 720EGT should still not overheat.

Paul

Post by **hdj105** » Fri Jan 25, 2008 9:56 am

rockcrawler31 wrote: remember that no diesel likes to labour with full throttle as unburnt diesel will bring up your egts and over heat the motor in no time flat. This includes towing, sand work, and hills. It could just be driving style.

The injection pump is a clever thing, it has a governor in it to ensure the engine only gets the fuel it's designed to.

If it's working correctly, it will always overide your foot and ensure the engine remains happy.

Post by **franku** » Thu Feb 07, 2008 8:03 pm

rockcrawler31 wrote:yeah some good advice on here and bad advice. Having had a 75x that had over heating problems i've gone through pretty much everything on a toyota's cooling system and know it backwards. Start with the cheap and easy stuff first

1. change fluid - $20-$30
2. Clean radiator fins AND air con fins thoroughly (you should be able to easily see through them) - Free
3. Thermostat - $20 bucks
4. Re oil fan clutch - $20 bucks
5. System pressure test and rad cap test - free if you ask nicely and a tenner for a rad cap

if these don't work then next to try is

5. have the rad core professionally rodded and cleaned Make sure you fit an inline filter to the inlet of the radiator hose when you refit and CHECK IT REGULARLY - $60-70 if you take out and give it to them saving the labour cost of removal and refit.
6. Test for compression gasses and bubbles in coolant (head gasket/head damage test) - free if you ask nicely or a tenner
7. Pump - 150 - 200 bucks if you remove and refit yourself. (make sure you learn how to reset timing for christ's sake)

After all of this if it still has drama's then i don't know. remember that no diesel likes to labour with full throttle as unburnt diesel will bring up your egts and over heat the motor in no time flat. This includes towing, sand work, and hills. It could just be driving style.

I agree totaly, but would like to add to this, with a diesel, it can be related to the tuning - too much fuel can cause heat issues.

Also, For the benefit of others,

First thing I would do is re-oil your fan clutch - if it has done 150,000K or more, this is probably the issue... Good news is that Toyota fan clutches are one of the only ones that you can renew the oil on and the oil comes from the Toyota dealer.

I have done a writeup with photos on how to do this by clicking this link:

How to top up your FAN CLUTCH OIL

If the issue is still there, then next thing to do is have the radiator POWER Flushed by a professional - not just flushed with a hose.

You also need to know that OEM Temp gauges have a dead spot by design. By the time that needle starts moving they are already close to boiling point.

I installed a Digital Temp Gauge with an alarm for this reason - as the temps it gives are accurate and don't hide a potential problem - this way, I get pre warning before it's too late - and the alarm lets me know regardless of who is driving and not neccesarily looking at the temp gauge.

You can get more info on the issue and the solution here:

TM-2 Digital Temp Gauge with Audible Alarm

Hope this helps someone...

Frank

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1HDT Radiator Viscous Fan Clutch, 80 Series Getting Hot

1HDT Radiator Viscous Fan Clutch, 80 Series Getting Hot

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