once you turn on the car,how long untill the fan comes on?
12-01-11, 08:20 PM
#36
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If any portion of the following doesn't make sense, let me know and I'll do my best to re-word it or if I can find my old clutch fan, I'll try to make a short video explaining the process's better, my car does not run so doing the running tests won't happen but I'll do my best to walk ya'll through it.
Here is a quick rundown of how THERMO CLUTCH FANS work.
1 When the thermo-couple (the metal center in the middle of the fan) is cold, it allows the fan to slip i.e. it's not in direct drive from the water pump, it is still turning because the engine is turning (it's never at a literal free-wheel, there is still resistance so that the fan is moving at all times)
2. When the thermo-couple heats up from the heat of the water pump, it begins to 'lock' and turns at a closer speed to that of the water pump itself thus pulling more air through the radiator to keep the car cool.
3. Once you get up above about 35-40mph, the airflow through the radiator generally exceeds that of what the fan could be pulling through and thus the fan is now pulling less air than the air being rammed in through the radiator, the clutch allows the fan to spin freely (within reason) as to not put excessive load on the water pump and the belts that drive it.
How to test to see if the clutch fan is bad:
1. With the car OFF, turn the clutch fan manually, try to give it a good flick, you should feel resistance to turn but it should not also just keep turning, given a stern flick it should rotate I'd say 90 degrees before stopping, this is an example of good operation.
1a. If the fan continues to rotate very easily with little to no effort, this is a sign of clutch failure and requires replacement and at least very careful monitoring of the engine temp under low speed conditions i.e. stop-and-go traffic.
1b. If the clutch fan is extremely hard to turn and feels completely binded or only turns when the actual water pump turns, this is also a sign of failure and requires replacement as now when you get above the 35-40mph range the fan cannot free-wheel and will begin to drag down the engine or cause the water pump to stall so to speak(turn at a different rate than the crank) and belts to slip.
2. With the car ON, use a newspaper or rolled up magazine with the car idling and slowly apply pressure to the fan blades to try and stop the fan from turning. It should take moderate effort to stop the fan and upon release should within 1-2 seconds resume full speed.
2a. If the clutch fan stops with little to no effort then refer to 1a.
2b. If the clutch fan is extremely hard to stop or will not stop without stalling the water pump, refer to 1b.
1 When the thermo-couple (the metal center in the middle of the fan) is cold, it allows the fan to slip i.e. it's not in direct drive from the water pump, it is still turning because the engine is turning (it's never at a literal free-wheel, there is still resistance so that the fan is moving at all times)
2. When the thermo-couple heats up from the heat of the water pump, it begins to 'lock' and turns at a closer speed to that of the water pump itself thus pulling more air through the radiator to keep the car cool.
3. Once you get up above about 35-40mph, the airflow through the radiator generally exceeds that of what the fan could be pulling through and thus the fan is now pulling less air than the air being rammed in through the radiator, the clutch allows the fan to spin freely (within reason) as to not put excessive load on the water pump and the belts that drive it.
How to test to see if the clutch fan is bad:
1. With the car OFF, turn the clutch fan manually, try to give it a good flick, you should feel resistance to turn but it should not also just keep turning, given a stern flick it should rotate I'd say 90 degrees before stopping, this is an example of good operation.
1a. If the fan continues to rotate very easily with little to no effort, this is a sign of clutch failure and requires replacement and at least very careful monitoring of the engine temp under low speed conditions i.e. stop-and-go traffic.
1b. If the clutch fan is extremely hard to turn and feels completely binded or only turns when the actual water pump turns, this is also a sign of failure and requires replacement as now when you get above the 35-40mph range the fan cannot free-wheel and will begin to drag down the engine or cause the water pump to stall so to speak(turn at a different rate than the crank) and belts to slip.
2. With the car ON, use a newspaper or rolled up magazine with the car idling and slowly apply pressure to the fan blades to try and stop the fan from turning. It should take moderate effort to stop the fan and upon release should within 1-2 seconds resume full speed.
2a. If the clutch fan stops with little to no effort then refer to 1a.
2b. If the clutch fan is extremely hard to stop or will not stop without stalling the water pump, refer to 1b.
As you can imagine, a fan gets progressively harder to turn the faster you turn it, the water pump is what drives the fan and the belts drive that, at high rpms the clutch in the fan is designed to allow the fan to slip so there isn't too much stress on the water pump, if the clutch has gone bad and is essentially deadlocked (no slipping) to the water pump, at a certain point the water pump can't turn the fan any faster but the engine is still speeding up the belt is going to slip on the pump...thus causing the squeal. when you take the fan off, there is nothing dragging the pump down meaning no squeal.
12-02-11, 05:03 PM
#41
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Ok so i did the newspapper test and i could stop the fan, and it would start spinning agian no problem so this is normal? even tho its always on and blowing air in the engine bay lol
12-02-11, 05:12 PM
#42
Post a video of that newspaper fan test so all those rookies out there can get it right. It's hard to tell what you mean by "its always on and blowing air in the engine bay", the video should show what you're talking about.
But it sounds like your fan clutch is fine. I'd like to know how many perfectly good clutch fans have been traded out because they don't "seem" to be working right.
You should do a video of a cold start up.
If the fan clutch is working normally, a few seconds after the engine starts it will engage and blow air like crazy for maybe 15-30 seconds.
Then it should disengage and quite down until things get really hot. Which is not very often.
Post it up!
But it sounds like your fan clutch is fine. I'd like to know how many perfectly good clutch fans have been traded out because they don't "seem" to be working right.
You should do a video of a cold start up.
If the fan clutch is working normally, a few seconds after the engine starts it will engage and blow air like crazy for maybe 15-30 seconds.
Then it should disengage and quite down until things get really hot. Which is not very often.
Post it up!
12-02-11, 05:45 PM
#43
if your clutch fan is bad, and you want to go the e-fan route, it's not as expensive as you'd think. mine was only $17.00. (didn't install a thermo switch) junk yards have these fans pretty cheap off of a taurus 3.8l engine i think. 10-20 bucks, relay off of same car or other nearby cars lol and a toggle switch like me or if you have an sa wire it into the tranny so it only comes on in low gears. or buy the kit for like 30 bucks at auto parts store that comes with all your wiring and relays and mounting kit.
i didn't need to make tabs, just trim the plastic a bit to acomodate for radiator hoses, used the same screws from the stock shroud and about all of them line up i think i had to use a washer for one of the corners but its been on there for over 3 years now.
after you get everything just follow this link it can be done very fast, hardest thing is hiding your wiring.
http://www.aaroncake.net/rx-7/efaninstall.htm
i didn't need to make tabs, just trim the plastic a bit to acomodate for radiator hoses, used the same screws from the stock shroud and about all of them line up i think i had to use a washer for one of the corners but its been on there for over 3 years now.
after you get everything just follow this link it can be done very fast, hardest thing is hiding your wiring.
http://www.aaroncake.net/rx-7/efaninstall.htm
04-26-12, 10:58 AM
#44
So it's off when you start the car, but then it comes on 3 seconds after the car has started? That sounds like it working right, so be sure that it really is locking up once it gets spinning. You may need to lean into it a little more with the newspaper once it gets spinning to slow it down, if it starts chewing up the rolled up paper with no effect on the fan speed then yeah, it probably really is locked.
What I don't get is why does it disengage later, so that it's not locked when you start up?
Anyway, assuming it's locking up then you are in the market for a fan clutch, which raises another question - are all the 12A FB fan clutches interchangeable or are they specific for some years?
As I recall the 82 GSL is different from the 84/85 GSL fan clutch, so an 84/85 GSL fan clutch may not fit your car.
Anybody know if they are?
If so, I have some spares from the 84/85 cars, send me a PM and mailing address and I'll get one out to you.
What I don't get is why does it disengage later, so that it's not locked when you start up?
Anyway, assuming it's locking up then you are in the market for a fan clutch, which raises another question - are all the 12A FB fan clutches interchangeable or are they specific for some years?
As I recall the 82 GSL is different from the 84/85 GSL fan clutch, so an 84/85 GSL fan clutch may not fit your car.
Anybody know if they are?
If so, I have some spares from the 84/85 cars, send me a PM and mailing address and I'll get one out to you.
I have an 83 and have the hurricane under the hood syndrome, I tried refilling the clutch but it still seems to spin the same speed as the engine. Its strange because with the clutch off the car i can loosen it up and it'll spin fairly freely by hand. Anyone else try repairing vs replacing one?
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