Converting from belt-driven fan to electric fan

[Scott in Florida]

I doubt if your aunt owned
a forklift

Now THERE is a great mind picture.....

LOL

 

[Scott in Florida]

But, I'm too young for FLA!!!

There are people down here below the age of dirt....LOL

 

[EdV]

Now THERE is a great mind picture.....

LOL

hahaha. The 4Y engine was on a RWD Toyota Crown and not a minivan and
much more a forklift.

 

[Twister Group]

hahaha. The 4Y engine was on a RWD Toyota Crown and not a minivan and
much more a forklift.

 

[Ray]

["Followup-To:" header set to alt.autos.subaru.]

So, it's a Winter-only car. I really don't need a fan running all the
time, and when you stop the car for a while and leave the engine running,
it really draws down the engine temp...almost to cold. So losing the
belt-driven fan won't really be too hard to take. I bet the thing hasn't
'turned on' for at least two weeks...

Sounds like your fan clutch, thermostat, or possibly both are sticking. I
havn't tried it on a Subie but on my Explorer the fan clutch is easy to
test. With the engine off and cold you should be able to turn the fan with
your hand. With the engine off and warm you shouldn't be able to turn it.
I'm with the others in saying that switching to an electric fan doesn't seem
like it would buy you over the existing system assuming it were working
properly. I also don't see why you would gain any milage since the energy
to turn the fan still needs to come from the engine but now with an extra
conversion to electricity at the alternator and then back to mechanical
energy at the fan motor. Every conversion will lose you some effeciency so I'd
expect the electric fan to actually use more gas rather than less.

 

[Steve]

It's also the only beater I have that won't see roads in the summertime
(the plate will be coming off it and going back on the Supra...)

So, it's a Winter-only car. I really don't need a fan running all the
time,

That's what the clutch on the engine-driven fan is for.

and when you stop the car for a while and leave the engine running,
it really draws down the engine temp...almost to cold.

Then fix the THERMOSTAT instead of spending all the money for an
electric fan. The fan isn't what's making the engine get too cool, its a
bad thermostat.

 

[Hachiroku]

That's what the clutch on the engine-driven fan is for.

But even with the clutch, the fan is always spinning. It never completely
stops. And with the weather here being in the single digits, air movement
other than from driving is not required.

Then fix the THERMOSTAT instead of spending all the money for an
electric fan. The fan isn't what's making the engine get too cool, its a
bad thermostat.

Thermostat's cool. When the car is running at a constant speed, or even
stop and start driving, the temp satys rock-steady. Only if I park for
more than 2 minutes does the temp drop.

At these temps, it seems even airflow from the fan idling is enough to
cool the engine.

 

[Hachiroku]

["Followup-To:" header set to alt.autos.subaru.]

So, it's a Winter-only car. I really don't need a fan running all the
time, and when you stop the car for a while and leave the engine running,
it really draws down the engine temp...almost to cold. So losing the
belt-driven fan won't really be too hard to take. I bet the thing hasn't
'turned on' for at least two weeks...

Sounds like your fan clutch, thermostat, or possibly both are sticking.

Thermostat seems OK. Haven't checked the fan, but my experience with Jap
cars is that if they go bad, they tend to idle rather than stick.

But, you bring up a good point...when I get it back from having the timing
belts changed, I'll check the fan...($180 rather than freezing my @$$ with
the car on jack stands and my work area a sheet of ice? I'll pay the $180...)



I

havn't tried it on a Subie but on my Explorer the fan clutch is easy to
test. With the engine off and cold you should be able to turn the fan with
your hand. With the engine off and warm you shouldn't be able to turn it.
I'm with the others in saying that switching to an electric fan doesn't seem
like it would buy you over the existing system assuming it were working
properly. I also don't see why you would gain any milage since the energy
to turn the fan still needs to come from the engine but now with an extra
conversion to electricity at the alternator and then back to mechanical
energy at the fan motor. Every conversion will lose you some effeciency so I'd
expect the electric fan to actually use more gas rather than less.

See my reply to Steve. We had one week in the 40's, one week in the
60's!!! and have been in the deep freeze ever since. I don't even think
the fan is needed at this point!!

 

[C. E. White]

But even with the clutch, the fan is always spinning. It never
completely
stops. And with the weather here being in the single digits, air
movement
other than from driving is not required.

Ahhh yes, but when you are forcing air through the radiator in excess
of what the fan draws when not moving, the fan is not drawing much
power, it is more like a windmill at that point. Again, if you have a
properly operating viscous clutch, the fan isn't going to draw
significant power. There is a certain amount of drag from the clutch
that causes the fan to rotate, but the power draw is tiny. If you want
to get into diagnostics, you'll need a variable strobe light. You
adjust the strobe until the fan appears to be not moving and then
compare that rpm to the engine rpm.

Thermostat's cool. When the car is running at a constant speed, or
even
stop and start driving, the temp satys rock-steady. Only if I park
for
more than 2 minutes does the temp drop.

At these temps, it seems even airflow from the fan idling is enough
to
cool the engine.

It still seems to me that there is a problem with the thermostat. Have
you verified operation of the fan clutch? One possibility is that the
clutch is frozen. There really should not be much difference between
idling and driving at moderate speeds as far as cooling is concerned.
I am surprised that the fan over-cools the car at idle, but you don't
experience over-cooling car when cruising at a steady 35 mph. Have you
actually tested the thermostat, or are you just assuming it is OK
because it seems OK when the engine is under load. It is possible that
the thermostat does not completely close so it cannot regulate
temperature at the low end. For the cost of a thermostat, I'd try a
new one before going overboard and installing an electrically operated
cooling fan.

Ed

 

[Mike Romain]

But even with the clutch, the fan is always spinning. It never completely
stops. And with the weather here being in the single digits, air movement
other than from driving is not required.




Thermostat's cool. When the car is running at a constant speed, or even
stop and start driving, the temp satys rock-steady. Only if I park for
more than 2 minutes does the temp drop.

At these temps, it seems even airflow from the fan idling is enough to
cool the engine.

The proper and working thermostat will 'close' and force the engine to
stay at it's setting of say 195F when you slow down the engine so you
keep the heater working, a broken thermostat will allow the engine to
cool down so you lose internal heat.

I just changed one like that in my Jeep and in a friends car, they were
broken 'open' so we couldn't keep heat up.

Thermostats are backward to what some think, they set how 'cold' an
engine can run, not how hot.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

 

[Jeff Strickland]

Ahhh yes, but when you are forcing air through the radiator in excess of
what the fan draws when not moving, the fan is not drawing much power, it
is more like a windmill at that point. Again, if you have a properly
operating viscous clutch, the fan isn't going to draw significant power.

I'm not sure how you got onto the power issue. His problem is heat.

He wants to remove the belt-driven fan and replace it with an electric fan.
His idea is that the air flowing from the moving fan slows the rate if
heat-rise, and if he can remove the belt-driven fan then he will get heat
faster.

I think his idea is flawed, and I would not consider it. But, I live where
bitter cold comes on when the thermometer hits 60 and stays there all day.







There is a certain amount of drag from the clutch

that causes the fan to rotate, but the power draw is tiny. If you want to
get into diagnostics, you'll need a variable strobe light. You adjust the
strobe until the fan appears to be not moving and then compare that rpm to
the engine rpm.


It still seems to me that there is a problem with the thermostat. Have you
verified operation of the fan clutch? One possibility is that the clutch
is frozen. There really should not be much difference between idling and
driving at moderate speeds as far as cooling is concerned. I am surprised
that the fan over-cools the car at idle, but you don't experience
over-cooling car when cruising at a steady 35 mph. Have you actually
tested the thermostat, or are you just assuming it is OK because it seems
OK when the engine is under load. It is possible that the thermostat does
not completely close so it cannot regulate temperature at the low end. For
the cost of a thermostat, I'd try a new one before going overboard and
installing an electrically operated cooling fan.

Ed

I agree with your assessement on the tstat. I think the tstat is the
trouble, but I think it is sticking open. An open tstat cause the cooant
temp to fall, when the coolant temp falls so much that the needle moves
below the mid-point, then the tstat is stuck open. When the car is moving,
there is work being done that generates heat, and the heat can overcome the
stuck open tstat, keeping the temp in a normal range. But, when the car
stops moving, the work stops, and a stuck open tstat can take out more heat
than is being generated, the result being a falling needle on the guage.

 

[Jeff Strickland]

The proper and working thermostat will 'close' and force the engine to
stay at it's setting of say 195F when you slow down the engine so you keep
the heater working, a broken thermostat will allow the engine to cool down
so you lose internal heat.

I just changed one like that in my Jeep and in a friends car, they were
broken 'open' so we couldn't keep heat up.

Thermostats are backward to what some think, they set how 'cold' an engine
can run, not how hot.

Another common mistake is in thinking that a tstat opens in a drive cycle,
then stays that way. A tstat opens and closes repeatedly throughout the
drive cycle.

 

[Steve]

But even with the clutch, the fan is always spinning. It never completely
stops. And with the weather here being in the single digits, air movement
other than from driving is not required.

That's deceptive, though. Aeordynamic forces usually increase as the
cube of velocity, so while the fan may appear to be spinning fairly
fast, it may be drawing virtually no power from the engine. The loudness
of the fan is a better indicator- on my car the fan will roar quite
loudly at fast idle, then go completely silent when the clutch
disengages.... but the eye can't really see any difference in the speed
of the fan.

Thermostat's cool. When the car is running at a constant speed, or even
stop and start driving, the temp satys rock-steady. Only if I park for
more than 2 minutes does the temp drop.

Then the thermostat is BAD. The temp should never drop if the thermostat
is doing its job. That's the whole point. What its probably doing is
sticking open rather than closing smoothly as the temperature of the
engine decreases. When the engine finally gets cold enough it will snap
shut, but that's not how its really supposed to work.

At these temps, it seems even airflow from the fan idling is enough to
cool the engine.

I don't doubt that. But the problem is still the thermostat if the
engine temperature falls below the normal operating temperature once its
gotten up there in the first place.

 

[Mike Romain]

Another common mistake is in thinking that a tstat opens in a drive
cycle, then stays that way. A tstat opens and closes repeatedly
throughout the drive cycle.

Or even open in the real cold...

I went to the beer store yesterday at -12C. The store is about a mile
and half away. I watched the computer gauge readout on the console in
our GM V6 car. I had heat on the way there, but only as I was getting
there, then I was back home in the driveway with lots of heat as the
temp hit 190F which meant the 192F T-stat hadn't opened nor had the
electric fan turned on.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

 

[Daniel Who Wants to Know]

That's deceptive, though. Aeordynamic forces usually increase as the cube
of velocity, so while the fan may appear to be spinning fairly fast, it
may be drawing virtually no power from the engine. The loudness of the fan
is a better indicator- on my car the fan will roar quite loudly at fast
idle, then go completely silent when the clutch disengages.... but the eye
can't really see any difference in the speed of the fan.



Then the thermostat is BAD. The temp should never drop if the thermostat
is doing its job. That's the whole point. What its probably doing is
sticking open rather than closing smoothly as the temperature of the
engine decreases. When the engine finally gets cold enough it will snap
shut, but that's not how its really supposed to work.

I don't doubt that. But the problem is still the thermostat if the engine
temperature falls below the normal operating temperature once its gotten
up there in the first place.

I agree with the sticking thermostat idea mostly but no one has mentioned
that the engine block itself does lose heat as it is a large chunk of metal
with cold air flowing over it. The outside temp at which the t-stat is
fully closed but due to heater core and direct heat loss the engine starts
to cool down below normal operating temp varies and is usually well below 0°
F but it is still a very remote possibility.

 

[drieszguesswhattozap]

Thermostat's cool. When the car is running at a constant speed, or even
stop and start driving, the temp satys rock-steady. Only if I park for
more than 2 minutes does the temp drop.

At these temps, it seems even airflow from the fan idling is enough to
cool the engine.

Hachiroku,

Make sure you're not confusing the thermostat with the temperature
guage. The guage on your dashboard may accurately tell you the
temperature of you engine coolant, but it will not tell you if the
thermostat is opening/closing correctly.

I used to drive a Subaru Loyale in Fairbanks, Alaska and regularly
experienced temperatures downwards of -40 degrees. Before leaving my
cabin in the morning, I'd let it idle for five or ten minutes and it
would warm up just fine.

The volume of air moved by the fan is pretty small compared to the
volume of air shoved through the radiator when the car is in motion.
(Granted, your engine is also making more heat under load, but it's
still making plenty at idle). You're engine temperature *shouldn't* drop
when idling, which is why so many posters are urging you to check out
your thermostat, the most likely culprit.

Regards,
Dave Riesz

 

[Ray O]

hahaha. The 4Y engine was on a RWD Toyota Crown and not a minivan and
much more a forklift.

The Crown hasn't been sold in the U.S. for quite a while, and it had a M
series engine back then. Obviously, your aunt isn't in the U.S.!

 

[Hachiroku]

Then the thermostat is BAD. The temp should never drop if the thermostat
is doing its job. That's the whole point. What its probably doing is
sticking open rather than closing smoothly as the temperature of the
engine decreases. When the engine finally gets cold enough it will snap
shut, but that's not how its really supposed to work.

I don't doubt that. But the problem is still the thermostat if the engine
temperature falls below the normal operating temperature once its gotten
up there in the first place.

Well, I think whatever is going to have to wait! Although I will try the
thermostat. I didn't *think* of being stuck *OPEN* !!!! :0

I took it to have the timing belts replaced. Timing belts are almost new...


Head gaskets are leaking...

Looks like Steel Seal for this one!!!