Where The Hell Is My Thermostat!!
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From: Vernon, BC
Where The Hell Is My Thermostat!!
gahhh I went to replace my stat and its NOT THERE! I dont know what the guy before me did, but there is no thermostat! what do I do now!? why isnt it there!?
edit: 1990 GX by the way
edit: 1990 GX by the way
If it's overheating... you've probably got bigger problems to worry about. You can run a car without a thermostat or a "cored" thermostat, (most don't reccomend it). It's been covered before. Search a bit and you should get all the info you want.
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From: Rohnert Park CA
Originally Posted by jono20
I have a new one. Im jsut wondering how the hell the car is operating without one (well really it isnt, its overheating) but isnt it sort of a vital part?
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Former Moderator. RIP Icemark.
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From: Rohnert Park CA
Originally Posted by jono20
to kick into its super loud fast speed? is it the clitch on the fan. or an electric signal
Now some models have a supplimental electric fan... do you mean that???
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From: Vernon, BC
no. it is the stock 90 fan.
so.. if I dont ever hear the fan getting really loud like it used to, and does in every other seven ive been in... the clutch in the fan is gone? im positive theres enough heat coming through the rad :P
so.. if I dont ever hear the fan getting really loud like it used to, and does in every other seven ive been in... the clutch in the fan is gone? im positive theres enough heat coming through the rad :P
Seduced by the DARK SIDE
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From: Orange Park FL (near Jax)
S4 - S5 fans have a different flange.
The thermostat has a spring loaded disc that sits about a inch below the main valve.
It covers a bypass port down in the pump housing.
If that port is open, about 1/3 of the coolant flow bypasses the radiator.
Both the S4 & S5 fan clutch freewheel when cold.
After 100,000 miles the bearing seals inside wear, and the bearing lube starts to weaken the clutch fluid's grip.
The s4 clutch increases it's bite gradually with temperature rise.
The s5 clutch is more on-off. (It just coasts until is gets warm)
Once they are warm, the fan speed goes up with engine speed to about 4000 RPM.
As the engine revs higher the fan stays at ~4K.
If your warmed up fan only revs up to < 2500 RPM, it's worn out.
The thermostat has a spring loaded disc that sits about a inch below the main valve.
It covers a bypass port down in the pump housing.
If that port is open, about 1/3 of the coolant flow bypasses the radiator.
Both the S4 & S5 fan clutch freewheel when cold.
After 100,000 miles the bearing seals inside wear, and the bearing lube starts to weaken the clutch fluid's grip.
The s4 clutch increases it's bite gradually with temperature rise.
The s5 clutch is more on-off. (It just coasts until is gets warm)
Once they are warm, the fan speed goes up with engine speed to about 4000 RPM.
As the engine revs higher the fan stays at ~4K.
If your warmed up fan only revs up to < 2500 RPM, it's worn out.
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From: Vernon, BC
Originally Posted by SureShot
S4 - S5 fans have a different flange.
The thermostat has a spring loaded disc that sits about a inch below the main valve.
It covers a bypass port down in the pump housing.
If that port is open, about 1/3 of the coolant flow bypasses the radiator.
Both the S4 & S5 fan clutch freewheel when cold.
After 100,000 miles the bearing seals inside wear, and the bearing lube starts to weaken the clutch fluid's grip.
The s4 clutch increases it's bite gradually with temperature rise.
The s5 clutch is more on-off. (It just coasts until is gets warm)
Once they are warm, the fan speed goes up with engine speed to about 4000 RPM.
As the engine revs higher the fan stays at ~4K.
If your warmed up fan only revs up to < 2500 RPM, it's worn out.
The thermostat has a spring loaded disc that sits about a inch below the main valve.
It covers a bypass port down in the pump housing.
If that port is open, about 1/3 of the coolant flow bypasses the radiator.
Both the S4 & S5 fan clutch freewheel when cold.
After 100,000 miles the bearing seals inside wear, and the bearing lube starts to weaken the clutch fluid's grip.
The s4 clutch increases it's bite gradually with temperature rise.
The s5 clutch is more on-off. (It just coasts until is gets warm)
Once they are warm, the fan speed goes up with engine speed to about 4000 RPM.
As the engine revs higher the fan stays at ~4K.
If your warmed up fan only revs up to < 2500 RPM, it's worn out.
Seduced by the DARK SIDE
Joined: Apr 2001
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From: Orange Park FL (near Jax)
The S5 water pump hub is different, so the S4 fan clutch won't fit.
For a temporary fix, try bending the heat sensing bi-metal strip on the front of the clutch outward.
For a temporary fix, try bending the heat sensing bi-metal strip on the front of the clutch outward.
BOOSTED Vert
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From: Miami
Originally Posted by Icemark
You would need a S4 housing and water pump to use a S4 fan
It will still work, but you wont be able to use like 1 or 2 bolts.. As long as he seals it good then he wont have anything to worry about.
I'm a boost creep...
Joined: Jan 2002
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From: Auckland, New Zealand
Originally Posted by jono20
gahhh I went to replace my stat and its NOT THERE! I dont know what the guy before me did, but there is no thermostat! what do I do now!?
what triggers the cooling fan to kick into its super loud fast speed?
so.. if I dont ever hear the fan getting really loud like it used to, and does in every other seven ive been in... the clutch in the fan is gone?
So when are you overheating?
Last edited by NZConvertible; Aug 20, 2005 at 12:44 AM.
BOOSTED Vert
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From: Miami
Originally Posted by NZConvertible
Um, put the new one in?
There's no such thing. Fan speed is dependant on engine speed and how much the clutch is engaged. Clutch engagement is determined by the temp of the air passing over it.
Fan clutch diagnosis is pretty easy. If the engine overheats under load or at speed, but not at idle, the fan clutch is fine. If the engine overheats at idle, but not under load or at speed, the fan clutch is fine.
So when are you overheating?
There's no such thing. Fan speed is dependant on engine speed and how much the clutch is engaged. Clutch engagement is determined by the temp of the air passing over it.
Fan clutch diagnosis is pretty easy. If the engine overheats under load or at speed, but not at idle, the fan clutch is fine. If the engine overheats at idle, but not under load or at speed, the fan clutch is fine.
So when are you overheating?
Passing life by
Joined: Feb 2005
Posts: 4,028
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From: Scotland, USA
Originally Posted by RXgirl7
make sure you get the correct thermostat(oem 180)the person who had my car before me put in a 210~ish one, so the car runs kinda hot...gonna replace that one reeeeaaaal soon... 
Originally Posted by Icemark
You would need a S4 housing and water pump to use a S4 fan
Former Moderator. RIP Icemark.
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From: Rohnert Park CA
Originally Posted by kompressorlogic
as a note the s4 water pump housing does NOT fit on the s5 motor, the lower radiator hose outlet, hits the electronic OMP, as i just found out the hard way.....