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Best place to install coolant temp sensor for e-fan?

Show of hands:
Who has replaced the fan clutch or fluid in it or damaged blades through normal use and wear?
I mean sure, you mean your 20-40 year old tstatic fan clutch that's all whooped and roached out doesn't work right?
Fluid is like 5 bux for an Aisin.
Blade is 10 bux if it's screwed up...outta balance/chewed?
Clutch assy 45-60 if leaking or questionable?

Both my cars had cold ac idling in hot weather with few fan clutch and radiator, and could be used to drag stuff over mountains in the hot without worry. No pusher fan. Other cars got a better pusher since they came with one. Like I said, in normal driving, everything "right" loud whoosh on take off with new, quiet not much after that in normal driving unless very heat soaked on a very hot day with the ac on.
 
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^That's not how the clutch works...it draws air through the rad spinning very slightly continuously over the spring on the front of the clutch.
Mechanically, it accomplishes a progressive smooth version of what a temp sensor or switch in the cold side of the radiator does coupled with either variable speed fan control or 1 or 2 stage relay.
If the radiator is all plugged up things will be skewed possibly...usually by that point it's such an old neglected pos if the rad is full of crud in and out that cooling problems, whatever they are, are inevitable.

I'll say it for the 3rd time though...brand new clutch, loud roar idling and on take off on a hot day that quiets down pretty fast...normal putting around driving. On returning to idle on a hot day, progressively louder roar in seconds to short minutes sitting idling in extreme heat/a/c on from fan being previously unlocked almost entirely. Fast reaction in either direction. In the winter you hear it on start-up for seconds and it pretty much just hangs out freewheeling, except idling for prolonged periods with the A/C on to defrost windows. If ambient temp is pretty cold...like freezing or colder, barely notable that there is any difference idling...very subtle on the timing light on the fan blade dot, but signifcant...1.5+ times as many dot passes at idle as previous basic freewheel.

Or if it's a hydraulic drive fan with electronic control, reacts same as electric.
 
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My Mother owned a 1988 Ford Taurus. V6 . E fan failed at 89,000 some odd miles. Efan failed, caused HG problems shortly thereafter. Have seen other efans fail when worked at Ford dealership and Toyota dealership too.

It's a cheap electric motor . Electric motors wear and fail. Quit acting like they *last forever*, for they do not. They are designed to last for a specific time period.

While it's likely the later efans are probably designed a little better than the earlier efans, nothing lasts forever.
 
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smokeyfan1000 said:
My Mother owned a 1988 Ford Taurus. V6 . E fan failed at 89,000 some odd miles. Efan failed, caused HG problems shortly thereafter. Have seen other efans fail when worked at Ford dealership and Toyota dealership too.

It's a cheap electric motor . Electric motors wear and fail. Quit acting like they *last forever*, for they do not. They are designed to last for a specific time period.

While it's likely the later efans are probably designed a little better than the earlier efans, nothing lasts forever.
Click to expand...

A diamond is forever and so are your cool stories.
 
I know they wear out. Clutch fans wear out too. Blew a HG on a Ford Aerostar because the clutch fan was out.
 
I installed a 'black magic' fan kit on my V8 245. It came with antemp'wand' that shoved thru the cold side of the radiator fine and stayed theoutside the coolant passages. It the. Had a rheostat/relay setup that allowed me to tune the on/off temp for the sensor.
It seemed home when I got it but it worked GREAT.
 
945ti said:
^That's not how the clutch works...it draws air through the rad spinning very slightly continuously over the spring on the front of the clutch.
Mechanically, it accomplishes a progressive smooth version of what a temp sensor or switch in the cold side of the radiator does coupled with either variable speed fan control or 1 or 2 stage relay.
If the radiator is all plugged up things will be skewed possibly...usually by that point it's such an old neglected pos if the rad is full of crud in and out that cooling problems, whatever they are, are inevitable.

I'll say it for the 3rd time though...brand new clutch, loud roar idling and on take off on a hot day that quiets down pretty fast...normal putting around driving. On returning to idle on a hot day, progressively louder roar in seconds to short minutes sitting idling in extreme heat/a/c on from fan being previously unlocked almost entirely. Fast reaction in either direction. In the winter you hear it on start-up for seconds and it pretty much just hangs out freewheeling, except idling for prolonged periods with the A/C on to defrost windows. If ambient temp is pretty cold...like freezing or colder, barely notable that there is any difference idling...very subtle on the timing light on the fan blade dot, but signifcant...1.5+ times as many dot passes at idle as previous basic freewheel.

Or if it's a hydraulic drive fan with electronic control, reacts same as electric.
Click to expand...

hmm, why would it roar on startup, when it is cold(ambient) and supposed to slip easily?
Wouldn't startup be the quietest time, and the clutch would be at it's loosest?

Your explanation makes little sense to me, as the temp of the clutch on a parked car will never go down once the engine starts.
 
apachechef said:
hmm, why would it roar on startup, when it is cold(ambient) and supposed to slip easily?
Wouldn't startup be the quietest time, and the clutch would be at it's loosest?

Your explanation makes little sense to me, as the temp of the clutch on a parked car will never go down once the engine starts.
Click to expand...

What's not clear?

On startup, the silicon fluid has not been sheared and is arranged throughout the clutch hub. This results in a mostly locked up condition. As soon as the thermostatic bi-metallic spring stays in the "cold" position on the front of the hub (cold outside, cold engine for example), the internal pump in the fan clutch pulls the fluid and directs the path of it such that there is little fluid being sheared against itself and the fan freewheels. For the first 30seconds to minute or whatever or as you first take off though, the fan is locked. Thereafter, as you drive throughout the winter, particularly with the heater on, the fan stays pretty much completely unlocked.

A small (or large..whether unlocked or locked) amount of air that is pulled through the radiator is always wafting over the bi-metallic t-stat spring on the front of the clutch hub. This spring is attached to a valve that directs the fluid flow in the hub. Over sheared fluid or a leaking or damaged hub will result in improper operation. On ones with over-sheared fluid or that would freewheel too much for the temperature, I would simply wind the t-stat spring a little tighter and smash it back in place to keep the car on the road without replacing the clutch. Works for quite a number of years, but isn't particularly efficient for fuel economy or a correct repair compared to replacing the fluid or clutch if leaking, worn or damaged. Many do not leak, but the fluid needs to be replaced.

By this mechanical means, it is doing as "Captain Bondo" describes a cold side switch or ECU control would do more or less;
bringing the water at the outlet of the radiator to an acceptable temperature (whatever that may be for your given engine) that the t-stat can regulate the engine temp. It works pretty well when it's working right. Seems good for ~100K-200K depending on use/duty etc before fluid change or replacement is required, or uh..reliable old hooptie car/clutch operation spring mod in CA LOL.

It can't be *that* terrible for fuel economy. 21-23mpg city in 740 turbo M46 pretty stock in excellent mechanical condition driving pretty normally, 28-32mpg highway 60-75mph cruise on, no real heavy load, A/C and hot or not. Savage beating on the car...probably bad fuel economy no matter what?

Nothing is perfect and lasts forever over time. Whether you use an appropriate electric cooling fan setup for the duty/use or a mechanical t-static clutch, or mechanical hydraulic fluid drive, some service and/or inspection will be required. If using the former, larger radiator, alternator, and appropriate control would be wise comparatively, generally.
A TIC car pulling a trailer at high elevation over time with the A/C blasting cold on a very hot day with water cooled turbo and perhaps oil/water heat exchanger/cold oil warmer is going to require a massive cooling system, especially if longevity is the primary concern.

The electric fan has it's advantages:
-Low mount sensor possible (if more than half the coolant is missing with any fan under stress, this will probably be problematic)
-Blade optimized for fixed speed (or two)...though many are variable speed/many many speeds now for noise and start-up current draw more than overall capacity (usually second fan or "hi" seed is used for that regardless).
-Less water pump wear (volvo specific?...not driven off the water pump on the Toyota always)...outta balance fan blade or shot clutch, belts and accessory bushings it will be more affected by I will definitely admit. I have almost 200K on a clutch fan water pump at the same time...CAKED in rust.
-Packaging flexibility (lol on the stockish volvo)
-High revving engine flexibility (it has a turbo on it, eh?)
-Theoretically more airflow at idle than a good clutch fan for A/C idling. (haven't really observed that significantly)
-Quieter...I guess? *shrug* Amazing any of you would point that out over your stereos and exhausts.
(all I care about is that first, second, and third reason more or less on the stockish volvo turbo driven everywhere)
In a light car, lots of airflow and frontal area, no A/C, N/A, with the heater on, not used for towing, fine. Barely need a fan/might not need one.
Hydraulic drive is kind of best of both if properly controlled, but can have costly wear parts, relatively, and install is pretty tailored to the car.
 
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945ti said:
- Savage beating on the car...probably bad fuel economy no matter what?

- A TIC car pulling a trailer at high elevation over time with the A/C blasting cold on a very hot day with water cooled turbo and perhaps oil/water heat exchanger/cold oil warmer is going to require a massive cooling system, especially if longevity is the primary concern.

-Packaging flexibility (lol on the stockish volvo)
-High revving engine flexibility (it has a turbo on it, eh?)

-Quieter...I guess? *shrug* Amazing any of you would point that out over your stereos and exhausts.
(all I care about is that first, second, and third reason more or less on the stockish volvo turbo driven everywhere)

*In a light car, lots of airflow and frontal area, no A/C, N/A, with the heater on, not used for towing, fine. Barely need a fan/might not need one.*
Click to expand...

You're really pushing how great this is for towing, eh?
I kinda thought this site was about cheap mods to make your car faster. i.e. making a non-stockish Volvo. I mean, you are posting in Performance/Suspension, I'd assume the car might be for performance/spirited driving and that his main concern isn't about how much cold air the A/C blows (what a window is for) while towing something over a mountain.

But hey, that's just me. Seems he's looking to take stress off the engine to allow it to rev faster, so making it so the fan isn't directly connected to the water pump pulley would seem like a good way of achieving that. And you guys are right, if he's going to increase his electrical load, he should look into an appropriately sized alternator, especially considering the OEM Bosch one's reputation for undercharging. And he should also make sure he's well versed on the thermostat's boundaries and how to set it up so it works most efficiently and doesn't cook his headgasket.

And since he claims to use his car for driving fast, and not for towing things over mountains with the A/C on (man, that just sounds like an exciting way to drive!), his set up should probably not be the exact same as yours, as they're both used for two different purposes.

Edit: In fact, he should probably delete the A/C system entirely, that would help with A: flowing air through the radiator/intercooler, and B: lower the weight of the car, thus giving better throttle response.
 
I wish for the car to perform better with more usable power without sacrificing the longevity (ideally improving it) or broad scope of use or comfort, generally.

I wish to be able to use it for either seamlessly, with good longevity and cost of upkeep without even thinking about it. Turn the key, do as I please, without much alteration/time/fuss. I'm in favor of that, however it works out best. I've had both, and came to the conclusions that I did for the scope of the use over time. And tore down the motor over time and put it back together, as well as tearing down and seeing many others.

I suppose the site is about "cheap mods?," isn't it? You are probably right about that.
I like to think it is about there being the cars and the community over time, however. But reality is what it is. Some of the views brought to the table are educated, experienced and varied, without any one being "wrong." Ill conceived for the application over time with many variables, maybe.
 
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945ti said:
I wish for the car to perform better with more usable power without sacrificing the longevity (ideally improving it) or broad scope of use or comfort, generally.

I wish to be able to use it for either seamlessly, with good longevity and cost of upkeep without even thinking about it. Turn the key, do as I please, without much alteration/time/fuss. I'm in favor of that, however it works out best.

I suppose the site is about "cheap mods?," isn't it? You are probably right about that.
I like to think it is about there being the cars and the community over time, however. But reality is what it is.
Click to expand...

And that's all gonna get you more out of your car than what he'd get out of that. I mean, I'm running a mech fan and I'm gonna replace that fan with another mech fan when it goes (I've got a spare in the garage).

But he's just asking what the best way to mount his coolant sensor. Answer is, down low, it'll give you better control on the fluid temp returning to the engine for better thermostat operation. If an e-fan fails (which they do), they stop spinning, I think he gets that. If a mech fan fails, it usually fails in the locked position, which doesn't risk blowing your engine. We all get that (I think). If he's willing to take the risk, might as well get him to do it properly. I'm gonna focus on stuff like fuel supply and boost, that'll get me more out of my car than an e-fan that acts as a risk/reward compromise for a slightly faster rev.

The thread didn't need to explode like this, he asked a question, he got an answer. If he's that concerned about blowing his engine, he wouldn't change the fan.

By the way, what about putting an LED somewhere on the dash that comes on when the fan turns on? That way if it stays off when you're pretty sure it should come on... Or just remove the compensator board. Whatever. Anyways, my .02.
 
So is a stopped, resting, ambient clutch when it spins the easiest by hand..?
I think a clod device spin easier, and get tougher to resist spinner as it cooks up in heat.

I can hand spin my LX450 fan easily after it just starts and hold it easily until
It get too hot.

Explain what should make a new clutch gripper at starting car grip welld, then get less grippy as you drive like you said above. .." warmer and get grippier," cools and more slipps., than stomp on it and the clutch grabs really hard. Are their changeover peaks in their heat range?
 
No no...it's simply that the fluid, in the resting clutch, is a solid mass distributed throughout. The spinning/shearing and pumping action with the valve in the cold position frees it up after initial start up pretty quickly. But on initial first start, the fan is close to "locked" by default on the stock Aisin.

Your Landcruiser? (91-97?) works mostly the same way (with larger parts, same brand usually...some late models are eaton and are unlocked at start I think unlike the Aisin), though they may have improved the speed at which it unlocks on start-up by redesigning it slightly or using slightly different fluid, or you may have a late model eaton one...those are quieter cold.

It does as you describe mostly...read my post...maybe I can find a picture diagram...or just pull one apart to change fluid...you will see how it works. A picture really is worth a thousand words.

As I said in earlier posts,T-static clutch have varied failure modes, electric have varied failure modes, or hydraulic drive have varied failure modes. Nothing is perfect. Some fail safes are probably good. I check the t-static clutch fan with the timing light/laser thermometer in varied conditions periodically, know what a good one feels and sounds like on start, and look for possible fluid leakage (usually at hub).
 
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James, thanks for the explanation of how the clutch works. I know most people won't absorb it or appreciate it, but for the record I appreciate it. Like you say, it's doing the mechanical equivalent of the sensor arrangement I suggest. I has no clue how how the coolant is at the thermostat housing is, and it doesn't care. People aren't going to understand that so I wouldn't worry too much.

If people want to peg their tstats wide open and then limit the absolute temp by the fan it's their perogative I guess. I have had my car on the dyno datalogging coolant temps using that approach- it is a "reactive" approach" instead of a "proactive" approach.

On a motor that makes relatively low hp/l, it's fine. On motors making north of 150hp/l, I found I got coolant temp spikes I did not like.


Regarding dynoing with the broken water pump- this was not done knowingly - I discoverted it was broken until after the fact. I thought I was approaching the limits of the radiator. It was only upon further investigate I discovered a cracked impeller.

I agree the clutch fan can deifnitely get the job done, but I will always recommend the later style (curved fins) 2 speed volvo electric fan as delivered in the WWD cars, driven with the big 60amp factory 2 speed relay. I've always just had awesome luck with them. I even use the volvo setup in the new (500hp) BMW project.
 
Yeah lulz...post engine warmup the water in the top hose is...wait for it...at about t-stat temp!

The electric fan as Volvo did it is decent, but they didnt just stuff it behind a 240 rad in a fully optioned out turbio a/c car with ancient wiring and old crummy alternator with temp sensor in the top hose either LOL. If they thought that would cut it and not lead to replacing engines, recall, or class action suit (OUCH!), they'd do it that way.

Whichever road you choose, the control and reasoning is sound, with inevitable oem bean counting basically. The clutch is undersized a bit to last, the efan uses one temp sensor and relay of ??? quality and motor of ??? quakity (good on the Volvo most of the time...few 850/70 ones have crapped out on me) yadda. As long as it works right in all conditions and doesn't Granade in warranty, they don't much care. If a fancier car, better the ac work and more seamless and quiet the better.
 
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Why is it locked up at startup in freezing areas and also locked up in superhot runs at speed
why is is locked up when ice cold and suerhot is my question, but loose at middle temps
Sorry for stupid q's, not at best mind level, I have just left a looong shift.thanks
 
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