Re: 2000 JGC V-8 overheating/ occasionally only !!
 

On Tue, 19 Dec 2006 04:40:33 -0600, herb@urusei.net (Herb Leong)
wrote:

>In article <vsiao2dbv91ha5f96pstehkidvpga7to79@4ax.com>,
>SnoMan <admin@snoman.com> wrote:
>#A clutch fan is centrifical and bimetal thermostat controlled. It
>#engages when the bimetal control lets fluid into clutch disc area
>#faster than centrifical force can remove it. This is why it can
>#sometimes cool better at low speed because the centrifical forces are
>#not purging fluid from it faster than it is being replaced. Also at
>#low speeds the engine is making less power on average and needs less
>#cooling generally. When you put a big V8 in a small car the cooling
>#system has to be just right for it to keep its cool. I would consider
>#a electric fan as a last resort because it cannot come close to
>#matching the air flow capabilies of a engine driven clutch fan. To do
>#so would require more electric power than you vehicle can produce to
>#sustain it.
>
>The WJ's v8 has a electricly driven fan in addition to the mechanically
>driven fan.
>
>/herb

The electric fan in a hybrid fan system is only intended to provide
airflow for the condenser at idle and low speed and the effect is gone
by 25 MPH vehicle speed.. It is rated in the 200 -250 W range.

A typical engine driven fan in a typical V8 SUV or Pick-up runs up to
around 5 HP which equals 4.3kW, far exceeding the alternator capacity.
Big blocks and diesels even more ...

Bi-Metal controlled fan clutches either work or they don't work, the
bi-metal adjustment mentioned elsewhere is either compensating for
poor initial calibration or the addition of additional heat exchangers
in the airstream (large aftermarket transmission oil coolers for
example). The amount of fluid in a clutch is pretty small so a small
leak quickly kills the clutch function.

Intermittent cooling system problems are nearly always related to
thermostat function or lower hose collapse at high RPM.


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Re: 2000 JGC V-8 overheating/ occasionally only !!
 

On Tue, 19 Dec 2006 04:40:33 -0600, herb@urusei.net (Herb Leong)
wrote:

>In article <vsiao2dbv91ha5f96pstehkidvpga7to79@4ax.com>,
>SnoMan <admin@snoman.com> wrote:
>#A clutch fan is centrifical and bimetal thermostat controlled. It
>#engages when the bimetal control lets fluid into clutch disc area
>#faster than centrifical force can remove it. This is why it can
>#sometimes cool better at low speed because the centrifical forces are
>#not purging fluid from it faster than it is being replaced. Also at
>#low speeds the engine is making less power on average and needs less
>#cooling generally. When you put a big V8 in a small car the cooling
>#system has to be just right for it to keep its cool. I would consider
>#a electric fan as a last resort because it cannot come close to
>#matching the air flow capabilies of a engine driven clutch fan. To do
>#so would require more electric power than you vehicle can produce to
>#sustain it.
>
>The WJ's v8 has a electricly driven fan in addition to the mechanically
>driven fan.
>
>/herb

The electric fan in a hybrid fan system is only intended to provide
airflow for the condenser at idle and low speed and the effect is gone
by 25 MPH vehicle speed.. It is rated in the 200 -250 W range.

A typical engine driven fan in a typical V8 SUV or Pick-up runs up to
around 5 HP which equals 4.3kW, far exceeding the alternator capacity.
Big blocks and diesels even more ...

Bi-Metal controlled fan clutches either work or they don't work, the
bi-metal adjustment mentioned elsewhere is either compensating for
poor initial calibration or the addition of additional heat exchangers
in the airstream (large aftermarket transmission oil coolers for
example). The amount of fluid in a clutch is pretty small so a small
leak quickly kills the clutch function.

Intermittent cooling system problems are nearly always related to
thermostat function or lower hose collapse at high RPM.


---
avast! Antivirus: Outbound message clean.
Virus Database (VPS): 0660-0, 12/19/2006
Tested on: 12/19/2006 9:43:14 PM
avast! - copyright (c) 1988-2006 ALWIL Software.
http://www.avast.com

Re: 2000 JGC V-8 overheating/ occasionally only !!
 

On Tue, 19 Dec 2006 04:40:33 -0600, herb@urusei.net (Herb Leong)
wrote:

>In article <vsiao2dbv91ha5f96pstehkidvpga7to79@4ax.com>,
>SnoMan <admin@snoman.com> wrote:
>#A clutch fan is centrifical and bimetal thermostat controlled. It
>#engages when the bimetal control lets fluid into clutch disc area
>#faster than centrifical force can remove it. This is why it can
>#sometimes cool better at low speed because the centrifical forces are
>#not purging fluid from it faster than it is being replaced. Also at
>#low speeds the engine is making less power on average and needs less
>#cooling generally. When you put a big V8 in a small car the cooling
>#system has to be just right for it to keep its cool. I would consider
>#a electric fan as a last resort because it cannot come close to
>#matching the air flow capabilies of a engine driven clutch fan. To do
>#so would require more electric power than you vehicle can produce to
>#sustain it.
>
>The WJ's v8 has a electricly driven fan in addition to the mechanically
>driven fan.
>
>/herb

The electric fan in a hybrid fan system is only intended to provide
airflow for the condenser at idle and low speed and the effect is gone
by 25 MPH vehicle speed.. It is rated in the 200 -250 W range.

A typical engine driven fan in a typical V8 SUV or Pick-up runs up to
around 5 HP which equals 4.3kW, far exceeding the alternator capacity.
Big blocks and diesels even more ...

Bi-Metal controlled fan clutches either work or they don't work, the
bi-metal adjustment mentioned elsewhere is either compensating for
poor initial calibration or the addition of additional heat exchangers
in the airstream (large aftermarket transmission oil coolers for
example). The amount of fluid in a clutch is pretty small so a small
leak quickly kills the clutch function.

Intermittent cooling system problems are nearly always related to
thermostat function or lower hose collapse at high RPM.


---
avast! Antivirus: Outbound message clean.
Virus Database (VPS): 0660-0, 12/19/2006
Tested on: 12/19/2006 9:43:14 PM
avast! - copyright (c) 1988-2006 ALWIL Software.
http://www.avast.com

Re: 2000 JGC V-8 overheating/ occasionally only !!
 

My WJ came from the factory with just an electric fan and it has never
overheated or run hot for that matter...


"reboot" <reboot@nothere.com> wrote in message
news:el7ho2hbim91t0ra6hkg72c14k0u9cu7qi@4ax.com...
> On Tue, 19 Dec 2006 04:40:33 -0600, herb@urusei.net (Herb Leong)
> wrote:
>
>>In article <vsiao2dbv91ha5f96pstehkidvpga7to79@4ax.com>,
>>SnoMan <admin@snoman.com> wrote:
>>#A clutch fan is centrifical and bimetal thermostat controlled. It
>>#engages when the bimetal control lets fluid into clutch disc area
>>#faster than centrifical force can remove it. This is why it can
>>#sometimes cool better at low speed because the centrifical forces are
>>#not purging fluid from it faster than it is being replaced. Also at
>>#low speeds the engine is making less power on average and needs less
>>#cooling generally. When you put a big V8 in a small car the cooling
>>#system has to be just right for it to keep its cool. I would consider
>>#a electric fan as a last resort because it cannot come close to
>>#matching the air flow capabilies of a engine driven clutch fan. To do
>>#so would require more electric power than you vehicle can produce to
>>#sustain it.
>>
>>The WJ's v8 has a electricly driven fan in addition to the mechanically
>>driven fan.
>>
>>/herb
>
> The electric fan in a hybrid fan system is only intended to provide
> airflow for the condenser at idle and low speed and the effect is gone
> by 25 MPH vehicle speed.. It is rated in the 200 -250 W range.
>
> A typical engine driven fan in a typical V8 SUV or Pick-up runs up to
> around 5 HP which equals 4.3kW, far exceeding the alternator capacity.
> Big blocks and diesels even more ...
>
> Bi-Metal controlled fan clutches either work or they don't work, the
> bi-metal adjustment mentioned elsewhere is either compensating for
> poor initial calibration or the addition of additional heat exchangers
> in the airstream (large aftermarket transmission oil coolers for
> example). The amount of fluid in a clutch is pretty small so a small
> leak quickly kills the clutch function.
>
> Intermittent cooling system problems are nearly always related to
> thermostat function or lower hose collapse at high RPM.
>
>
> ---
> avast! Antivirus: Outbound message clean.
> Virus Database (VPS): 0660-0, 12/19/2006
> Tested on: 12/19/2006 9:43:14 PM
> avast! - copyright (c) 1988-2006 ALWIL Software.
> http://www.avast.com
>
>
>

Re: 2000 JGC V-8 overheating/ occasionally only !!
 

My WJ came from the factory with just an electric fan and it has never
overheated or run hot for that matter...


"reboot" <reboot@nothere.com> wrote in message
news:el7ho2hbim91t0ra6hkg72c14k0u9cu7qi@4ax.com...
> On Tue, 19 Dec 2006 04:40:33 -0600, herb@urusei.net (Herb Leong)
> wrote:
>
>>In article <vsiao2dbv91ha5f96pstehkidvpga7to79@4ax.com>,
>>SnoMan <admin@snoman.com> wrote:
>>#A clutch fan is centrifical and bimetal thermostat controlled. It
>>#engages when the bimetal control lets fluid into clutch disc area
>>#faster than centrifical force can remove it. This is why it can
>>#sometimes cool better at low speed because the centrifical forces are
>>#not purging fluid from it faster than it is being replaced. Also at
>>#low speeds the engine is making less power on average and needs less
>>#cooling generally. When you put a big V8 in a small car the cooling
>>#system has to be just right for it to keep its cool. I would consider
>>#a electric fan as a last resort because it cannot come close to
>>#matching the air flow capabilies of a engine driven clutch fan. To do
>>#so would require more electric power than you vehicle can produce to
>>#sustain it.
>>
>>The WJ's v8 has a electricly driven fan in addition to the mechanically
>>driven fan.
>>
>>/herb
>
> The electric fan in a hybrid fan system is only intended to provide
> airflow for the condenser at idle and low speed and the effect is gone
> by 25 MPH vehicle speed.. It is rated in the 200 -250 W range.
>
> A typical engine driven fan in a typical V8 SUV or Pick-up runs up to
> around 5 HP which equals 4.3kW, far exceeding the alternator capacity.
> Big blocks and diesels even more ...
>
> Bi-Metal controlled fan clutches either work or they don't work, the
> bi-metal adjustment mentioned elsewhere is either compensating for
> poor initial calibration or the addition of additional heat exchangers
> in the airstream (large aftermarket transmission oil coolers for
> example). The amount of fluid in a clutch is pretty small so a small
> leak quickly kills the clutch function.
>
> Intermittent cooling system problems are nearly always related to
> thermostat function or lower hose collapse at high RPM.
>
>
> ---
> avast! Antivirus: Outbound message clean.
> Virus Database (VPS): 0660-0, 12/19/2006
> Tested on: 12/19/2006 9:43:14 PM
> avast! - copyright (c) 1988-2006 ALWIL Software.
> http://www.avast.com
>
>
>

Re: 2000 JGC V-8 overheating/ occasionally only !!
 

My WJ came from the factory with just an electric fan and it has never
overheated or run hot for that matter...


"reboot" <reboot@nothere.com> wrote in message
news:el7ho2hbim91t0ra6hkg72c14k0u9cu7qi@4ax.com...
> On Tue, 19 Dec 2006 04:40:33 -0600, herb@urusei.net (Herb Leong)
> wrote:
>
>>In article <vsiao2dbv91ha5f96pstehkidvpga7to79@4ax.com>,
>>SnoMan <admin@snoman.com> wrote:
>>#A clutch fan is centrifical and bimetal thermostat controlled. It
>>#engages when the bimetal control lets fluid into clutch disc area
>>#faster than centrifical force can remove it. This is why it can
>>#sometimes cool better at low speed because the centrifical forces are
>>#not purging fluid from it faster than it is being replaced. Also at
>>#low speeds the engine is making less power on average and needs less
>>#cooling generally. When you put a big V8 in a small car the cooling
>>#system has to be just right for it to keep its cool. I would consider
>>#a electric fan as a last resort because it cannot come close to
>>#matching the air flow capabilies of a engine driven clutch fan. To do
>>#so would require more electric power than you vehicle can produce to
>>#sustain it.
>>
>>The WJ's v8 has a electricly driven fan in addition to the mechanically
>>driven fan.
>>
>>/herb
>
> The electric fan in a hybrid fan system is only intended to provide
> airflow for the condenser at idle and low speed and the effect is gone
> by 25 MPH vehicle speed.. It is rated in the 200 -250 W range.
>
> A typical engine driven fan in a typical V8 SUV or Pick-up runs up to
> around 5 HP which equals 4.3kW, far exceeding the alternator capacity.
> Big blocks and diesels even more ...
>
> Bi-Metal controlled fan clutches either work or they don't work, the
> bi-metal adjustment mentioned elsewhere is either compensating for
> poor initial calibration or the addition of additional heat exchangers
> in the airstream (large aftermarket transmission oil coolers for
> example). The amount of fluid in a clutch is pretty small so a small
> leak quickly kills the clutch function.
>
> Intermittent cooling system problems are nearly always related to
> thermostat function or lower hose collapse at high RPM.
>
>
> ---
> avast! Antivirus: Outbound message clean.
> Virus Database (VPS): 0660-0, 12/19/2006
> Tested on: 12/19/2006 9:43:14 PM
> avast! - copyright (c) 1988-2006 ALWIL Software.
> http://www.avast.com
>
>
>

Re: 2000 JGC V-8 overheating/ occasionally only !!
 

you can find almost exact statement in the service manul

SnoMan wrote:

> On Sun, 17 Dec 2006 17:45:10 -0500, philthy <dbrider@cac.net> wrote:
>
> >spin the fan while it is cold and if there is a drag on the fan then it is ok
>
> Not alway true, all it does tell you if the fluid has leaked out of it
> because it leaks in to clutch area normally when it sits overnight
> after gettting warm. It does not tell you if the bimetal coil is
> working properly for your tempature conditions.
> -----------------
> TheSnoMan.com

Re: 2000 JGC V-8 overheating/ occasionally only !!
 

you can find almost exact statement in the service manul

SnoMan wrote:

> On Sun, 17 Dec 2006 17:45:10 -0500, philthy <dbrider@cac.net> wrote:
>
> >spin the fan while it is cold and if there is a drag on the fan then it is ok
>
> Not alway true, all it does tell you if the fluid has leaked out of it
> because it leaks in to clutch area normally when it sits overnight
> after gettting warm. It does not tell you if the bimetal coil is
> working properly for your tempature conditions.
> -----------------
> TheSnoMan.com

Re: 2000 JGC V-8 overheating/ occasionally only !!
 

you can find almost exact statement in the service manul

SnoMan wrote:

> On Sun, 17 Dec 2006 17:45:10 -0500, philthy <dbrider@cac.net> wrote:
>
> >spin the fan while it is cold and if there is a drag on the fan then it is ok
>
> Not alway true, all it does tell you if the fluid has leaked out of it
> because it leaks in to clutch area normally when it sits overnight
> after gettting warm. It does not tell you if the bimetal coil is
> working properly for your tempature conditions.
> -----------------
> TheSnoMan.com

Re: Re: 2000 JGC V-8 overheating/ occasionally only !!
 

On Wed, 20 Dec 2006 18:56:16 -0500, philthy <dbrider@cac.net> wrote:

>you can find almost exact statement in the service manul


Service manual is not the gosphel and one reason why there are so
mnay TSB's and updates on them because they are not always 100%
correct. Spinning it will just tell you if there is still fluid in it,
not if it is calibrated properly
-----------------
TheSnoMan.com