Overheating gone

[thelal]

Was having problems over last year with overheating on mountain climbs (Going from 5000ft up to 9Kft).

Had done 'tests' for fan clutch (paper in front of rad) and tests for head gasket (compression test, bubbles in overflow) and all seemed fine.
Robbie diagnosed the 'bad' fan clutch even though worked (but not good enough) with his infamous grab technique.

Replaced fan clutch few weeks ago and noticed a more siginificant 'whoosh' on startup (i.e. noiser).

Going back up towards Vail (9-10K ft) last weekend no overheating. Temp needle no budge and pushing 4400 revs for several mins. (Would previously move if above 3300 for 3 mins and in 3th gear).

Lal with 1996 and 103K in Colorado
(note from previous posts that replaced my radiator with new Toyo rad last year as other one gunged up).

 

[PHAEDRUS]

just my take here but any truck over 100 k this should be done. I was amazed at how much cooler my truck ran after I put mine on. also had better engagement once I ditched the pos am belts and put on the oem style. note this is on a 3FE. Glad to hear your are running well brendan.
Dave

 

[Lars]

[quote author=thelal link=board=2;threadid=14355;start=msg134037#msg134037 date=1081302313]

Robbie diagnosed the 'bad' fan clutch even though worked (but not good enough) with his infamous grab technique.

[/quote]

Care to elaborate on this technique?

 

[IdahoDoug]

Ditto

 

[alia176]

I assume they're referring to rotating the fan blade by hand and there should be resistance while turning? If no resistance=viscous coupling is shot.

Ali

 

[robbie]

THE TEST FOR THIS CAN RESULT IN INJURY IF NOT DONE RIGHT, AND CAN INJURY YOU IF DONE RIGHT.
That said I will assume no responsiability for injury.
Your truck must be fully warmed up, usually I will drive a truck up the hills to get it really warm. It will take 2 people to do this test. I usually use a thick leather glove on my left hand. After warming up the engine, shut it off. The person in side must watch the temp guage and the rpm's. THe person holding must pay attenetion to what he is doing.
SO I THEN HOLD THE FAN BLADE WITH MY LEFT HAND, I HAVE THE PERSON START THE ENGINE. THE FAN BLADE WILL TRY AND TAKE OFF, I HAVE ALWAYS BEEN ABLE TO HOLD THE BLADE. I DO THIS WITH JUST MY FINGERS ON THE CRUVE PART OF THE BLADE. THIS IS DONE TO ALLOW THE FAN THE CHANCE TO LOCK UP AND FULLY ENGAGE. THIS IS WHEN YOU CAN GET HURT. IF YOU DO NOT ALLOW THE FAN TO TAKE OFF IT WILL BRAKE A FINGER OR SUCK YOUR HAND INTO THE ENGINE.
I was not yelling but want you to get this is serious and if you are not willing to pay attention to what you are doing you can get hurt.
So if as the temp raises up past the regular postion you normally see and get close to the red mark and the fan has not engaged you have a bad fan clutch. If at some point the blade engages and it startles you as it take off and wacks your fingers it is a good clutch.
later robbie

 

[RavenTai]

how much is a replacement clutch?

Robbie, that test sounds about as scary as hand propping aircraft engines, I guess the plastic fan blade is less likely to take off a finger as the old sheet metal fans but stills seams like it could put a hurting on you if something goes wrong

 

[PHAEDRUS]

till c bizkit chimes in I believe list was around 115 and smart shopper would be a little less. it is a paint to swap out with the radiator in place but it can be done.
Dave

 

[cruiserdan]

16210-66020 for a 1FZ.

List is $131.10. A smartshopper could find one for about 98 bucks.

 

[RavenTai]

are there any other indications of failure? I have seen a Tacoma that had a lot of play between the input shaft and clutch, I guess that says more about the bearings that the state of the fluid in the clutch

 

[PHAEDRUS]

other than the difference in noise level or lack thereof. if it is warm and you are hard on it you should hear it. cheap insurance on a sensitive system if you ask me.
Dave

 

[RavenTai]

I see, I'll have to try to pay more attention next time I take it for a spin, now that you mention it my engine is very quiet, don't think i have ever heard the fan roar,

now that it is getting warmer, when I open the hood after a good long stop of go traffic run it feels very hot under there, I cna actually fell the heat radiating, this has been bothering me especially with the “I not going to tell you until it is to late” temp gage, I already flushed the system and replaced the thermostat as PM, I had not thought about the clutch,

on my Chevy it would make a lot of noise when the fan kicked in full. It did this often with the AC running in the summer in traffic, and oddly just after start on very cold mornings, rest of the time it could not be heard

I need to get one of those non contact infrared thermometers

 

[Landpimp]

alot of you will disagree with me, but if your cooling system is up to par then on the highway the fan clutch should have no effect on the temps.

while moving slowly or ideling in trafic yes the fan clutch will effect the temps.

the test I like, block the rad off with something(cardboard or?) close the hood, start up the Cruiser, and let it warm up, after it gets warm you will hear(and see) the clutch kick in, there will be no missing it as it get loud and will suck the cardboard to the grill. Once you hear/see it kick in, remove the cardboard and you will hear it kick off in just a short time.

 

[mabrodis]

I had the exact experience as Brendan, infact I'm even the one who replaced his, and still have the cut on my hand to prove it.

Mine would get hot when really on it, climbing up out of Denver, into the moutains, long hills, running well over 4000 rpms for 10+ minutes, wide open throttle (what other way is there! ). I did all the head gasket tests too, I *thought* I did see little bubbles in the radiator overflow when really hot and revving, but it was so hard to tell, and hard to think when my friend is revving the engine to like 4000 rpms and my head is under the hood.

Robbie did the same test with mine, after we drove it around with Christo's laptop, looking at the OBD2 stuff, it would get hot when you jumped on it, even in town, but then it would get rid of the heat pretty fast also, at that point we guessed head gasket. Got back to Christo's shop, Robbie did his test which doesn't seem that dangerous to me, just don't hold the fan with your arm, hold it with your finger, if it yanks it off your finger fine, don't make it take you along with the fan. We determined it was either the head gasket AND the fan clutch or just the fan clutch.

So me being damn cheap, I took the old fan clutch out and drilled holes through it, front to back about 2" out from the center and put bolts all the way through it. That makes the clutch part not work, the bolts jam the disc inside and it is just like no fan clutch at all, just spins with the engine, positively locked up. That made a huge difference, no overheating at all, sounds like a fricken airplace, and steals a crapload of power, I can see why they don't have the fan spin that much normally, it is VERY noticable how much power you lose when you spin it directly with the engine.

So now I had either proven the fan clutch was bad, since my cheap-bastard approach did not overheat at all, or that the head gasket was still trying to get it hot but the fan was spinning so much more than normal, probably more than even a good fan clutch would have, that it was masking the fact that the head gasket still was bad.

I replaced the fan clutch and drove the snot out of it and gauge never budges now.

I don't know if you had a bad head gasket if it would still overheat even with the fan spinning that much, my gut feeling is it would, since even spinning the fan that much, it couldn't get rid of that much extra heat I don't think.

So, I have a hacked fan clutch if anyone wants it for free to test out their overheating issues.

Takes about 10-15 minutes to change the fan clutch, very easy and great time to do all the belts too. And now when you look in my engine compartment there is atleast one shiny new part in there.

If anyone is curious on specifics how to change the fan clutch PM me..

Later..
Mark Brodis

 

[PHAEDRUS]

I like pimps test better than robbies.
sounds like a good way to go. I swapped mine prior to hauling a trailer from salt lake city to bellingham as a just in case.
Dave

 

[robbie]

THe carboard test is ok. You will be able to see if the fluid (inside the clutch)is released into the clutch area because it locks up partially. Brendens clutch was this way, it tried to lock up and wanted to take off but did not fully engage. So if it is partially engaged it will suck the carboard up, but it may or may not fully engage.
As for the vechicle not needing the extra air flow, yes at times it will need it. Electric fans have been discussed on many boards ( I am too new to this one to know if they have been discussed here), and the bottom line is that these fan are designed to pull 12000 cubic a minute (a number given to us from Norm in OZ). Yes there are time when the cooling system will need it. Slow crawling on a hot day, long runs on hot days. and many other situations.
If you are not hearing it engage first thing in the moring, this might be a clue. If on long hills you are not hearing it, this might be a clue. If in traffic with the a/c is on and you are not moving and you do not hear it an the needle creaps up, this might be a clue.
The definitive test for me is the one I describe to you. If you want to replace as a service item then around 100-120k miles go for it. Most I have seen here have needed replacement at or around these milage. later robbie

 

[landtank]

I replaced mine during the overhaul. Torqflow at Autozone $65.00. Fit fine and noticed an immediate difference in sound and air flow.

 

[thelal]

Robbie is correct in that on mine it passed the cardboard test but failed Robbie's hand test (and mountain roads to Vail outa Denver). So beware of false assumptions.

 

[zander]

Is it possible to replace the fan clutch on an HJ60 (2H diesel) without a big tear down? The maual says to drain all coolant and take apar the water pump etc, but that seems like more than necessary.

thanks for any advice