Mike Romain

Have a close eyeball at the heater hoses guys!

On both my CJ7 and my Cherokee I has really shitty heat. The Cherokee
was even worse than the CJ!

In both of my cases, the heater hoses ran above the level of the fluid
in the rad.

This makes for one sneaky air lock.

I dropped them down so they run below the fluid level in the rad and no
more troubles, I have all it can give and then some in the CJ7.

In the CJ7 I put a monster GM blower motor from a 73 Blazer, 350, 4x4
with AC. It fits right in and the fan fits right on. Word of caution,
one parts supplier in the US seems to have the wrong blower motor
listed. The shaft is too long, so it is best to take yours with you so
you get the right one. Here is a link on the upgrade:

http://www.off-road.com/jeep/tech/body/heater.html

And before you go ripping dashes off to get to it, run a garden hose
through it to see if it is actually plugged up or not. Try both heater
core hose nipples, the in and out so it gets back flushed.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

"Pablo Riofrío G." wrote:
>
> I am having the SAME problem on my CJ-7. Do you guys know if I have to take
> the dash completely off to access the heater core?
>
> Thanks
>
> --
> - Pablo
>
> 1981 CJ-7 Laredo 360 V8
> 2000 WJ Laredo V8 QuadraDrive
> 2003 TJ Rubicon
>
> "lee" <mrlee727@hotmail.com> wrote in message
> news:21fdf96c.0310210841.43e9c04b@posting.google.c om...
> > Hi I have an 89 YJ that is pumping cold air but the temp gauge is
> > reading 210 degs. I just change the thermostat hoping to fix the
> > problem but still having the same issue.
> >
> > I think that there is either a clog or air lock but I'm not sure how
> > to test it or fix. I was thinking of flushing the system but have
> > never done that on this vehicle before. I've run the car with the
> > radiator cap off and did not see any circulation of fluids. I also
> > noticed that the hoses going and coming out of the firewall are cool.
> >
> > Any help is appreciated.

Mike Romain

Have a close eyeball at the heater hoses guys!

On both my CJ7 and my Cherokee I has really shitty heat. The Cherokee
was even worse than the CJ!

In both of my cases, the heater hoses ran above the level of the fluid
in the rad.

This makes for one sneaky air lock.

I dropped them down so they run below the fluid level in the rad and no
more troubles, I have all it can give and then some in the CJ7.

In the CJ7 I put a monster GM blower motor from a 73 Blazer, 350, 4x4
with AC. It fits right in and the fan fits right on. Word of caution,
one parts supplier in the US seems to have the wrong blower motor
listed. The shaft is too long, so it is best to take yours with you so
you get the right one. Here is a link on the upgrade:

http://www.off-road.com/jeep/tech/body/heater.html

And before you go ripping dashes off to get to it, run a garden hose
through it to see if it is actually plugged up or not. Try both heater
core hose nipples, the in and out so it gets back flushed.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

"Pablo Riofrío G." wrote:
>
> I am having the SAME problem on my CJ-7. Do you guys know if I have to take
> the dash completely off to access the heater core?
>
> Thanks
>
> --
> - Pablo
>
> 1981 CJ-7 Laredo 360 V8
> 2000 WJ Laredo V8 QuadraDrive
> 2003 TJ Rubicon
>
> "lee" <mrlee727@hotmail.com> wrote in message
> news:21fdf96c.0310210841.43e9c04b@posting.google.c om...
> > Hi I have an 89 YJ that is pumping cold air but the temp gauge is
> > reading 210 degs. I just change the thermostat hoping to fix the
> > problem but still having the same issue.
> >
> > I think that there is either a clog or air lock but I'm not sure how
> > to test it or fix. I was thinking of flushing the system but have
> > never done that on this vehicle before. I've run the car with the
> > radiator cap off and did not see any circulation of fluids. I also
> > noticed that the hoses going and coming out of the firewall are cool.
> >
> > Any help is appreciated.

Mike Romain

Have a close eyeball at the heater hoses guys!

On both my CJ7 and my Cherokee I has really shitty heat. The Cherokee
was even worse than the CJ!

In both of my cases, the heater hoses ran above the level of the fluid
in the rad.

This makes for one sneaky air lock.

I dropped them down so they run below the fluid level in the rad and no
more troubles, I have all it can give and then some in the CJ7.

In the CJ7 I put a monster GM blower motor from a 73 Blazer, 350, 4x4
with AC. It fits right in and the fan fits right on. Word of caution,
one parts supplier in the US seems to have the wrong blower motor
listed. The shaft is too long, so it is best to take yours with you so
you get the right one. Here is a link on the upgrade:

http://www.off-road.com/jeep/tech/body/heater.html

And before you go ripping dashes off to get to it, run a garden hose
through it to see if it is actually plugged up or not. Try both heater
core hose nipples, the in and out so it gets back flushed.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

"Pablo Riofrío G." wrote:
>
> I am having the SAME problem on my CJ-7. Do you guys know if I have to take
> the dash completely off to access the heater core?
>
> Thanks
>
> --
> - Pablo
>
> 1981 CJ-7 Laredo 360 V8
> 2000 WJ Laredo V8 QuadraDrive
> 2003 TJ Rubicon
>
> "lee" <mrlee727@hotmail.com> wrote in message
> news:21fdf96c.0310210841.43e9c04b@posting.google.c om...
> > Hi I have an 89 YJ that is pumping cold air but the temp gauge is
> > reading 210 degs. I just change the thermostat hoping to fix the
> > problem but still having the same issue.
> >
> > I think that there is either a clog or air lock but I'm not sure how
> > to test it or fix. I was thinking of flushing the system but have
> > never done that on this vehicle before. I've run the car with the
> > radiator cap off and did not see any circulation of fluids. I also
> > noticed that the hoses going and coming out of the firewall are cool.
> >
> > Any help is appreciated.

Richard M. Hinchliffe

"JimG" <jimg@cj7.com> wrote in message news:<gQdlb.13195$Qx7.6514@news01.roc.ny>...
> > I just change the thermostat hoping to fix the
> > problem but still having the same issue.
>
> Yep, the thermostat would control how hot your heater might get, but would
> not keep it from producing some kind of heat.
>
> > I think that there is either a clog or air lock
>
> Yep, could even be a bad heater core.
>
> > I was thinking of flushing the system but have
> > never done that on this vehicle before.
>
> No time to learn like the present. Your local auto store sells flush kits
> with directions.
>


With a flush kit, won't the water just take the path of least
resistance? Going out the other end (radiator) and not unplugging
the heater core?
If the heater core is plugged wouldn't you need to put your hose right
up to the heater core inlet?
RMH

Richard M. Hinchliffe

"JimG" <jimg@cj7.com> wrote in message news:<gQdlb.13195$Qx7.6514@news01.roc.ny>...
> > I just change the thermostat hoping to fix the
> > problem but still having the same issue.
>
> Yep, the thermostat would control how hot your heater might get, but would
> not keep it from producing some kind of heat.
>
> > I think that there is either a clog or air lock
>
> Yep, could even be a bad heater core.
>
> > I was thinking of flushing the system but have
> > never done that on this vehicle before.
>
> No time to learn like the present. Your local auto store sells flush kits
> with directions.
>


With a flush kit, won't the water just take the path of least
resistance? Going out the other end (radiator) and not unplugging
the heater core?
If the heater core is plugged wouldn't you need to put your hose right
up to the heater core inlet?
RMH

Richard M. Hinchliffe

"JimG" <jimg@cj7.com> wrote in message news:<gQdlb.13195$Qx7.6514@news01.roc.ny>...
> > I just change the thermostat hoping to fix the
> > problem but still having the same issue.
>
> Yep, the thermostat would control how hot your heater might get, but would
> not keep it from producing some kind of heat.
>
> > I think that there is either a clog or air lock
>
> Yep, could even be a bad heater core.
>
> > I was thinking of flushing the system but have
> > never done that on this vehicle before.
>
> No time to learn like the present. Your local auto store sells flush kits
> with directions.
>


With a flush kit, won't the water just take the path of least
resistance? Going out the other end (radiator) and not unplugging
the heater core?
If the heater core is plugged wouldn't you need to put your hose right
up to the heater core inlet?
RMH

c

"Richard M. Hinchliffe" <hinchlif@neuro.usc.edu> wrote in message
news:d3dde951.0310211843.31ef7ae5@posting.google.c om...
> "JimG" <jimg@cj7.com> wrote in message
news:<gQdlb.13195$Qx7.6514@news01.roc.ny>...
> > > I just change the thermostat hoping to fix the
> > > problem but still having the same issue.
> >
> > Yep, the thermostat would control how hot your heater might get, but
would
> > not keep it from producing some kind of heat.
> >
> > > I think that there is either a clog or air lock
> >
> > Yep, could even be a bad heater core.
> >
> > > I was thinking of flushing the system but have
> > > never done that on this vehicle before.
> >
> > No time to learn like the present. Your local auto store sells flush
kits
> > with directions.
> >
>
>
> With a flush kit, won't the water just take the path of least
> resistance? Going out the other end (radiator) and not unplugging
> the heater core?
> If the heater core is plugged wouldn't you need to put your hose right
> up to the heater core inlet?
> RMH

OK, I need to chime in here (again). The flushing kits you can buy in the
stores are just about useless. they will remove the sludge and crud that is
laying in the radiator or heater core, but they do nothing to remove the
calcium and mineral deposits in these things. If you can't get water to flow
through the heater core, just replace it. the core openings are so much
smaller than a radiator core and they will scale up faster than a radiator.
The radiator shops use a very diluted muriatic acid solution to attempt to
remove the scale with the core or radiator removed from the vehicle, but the
success rate is low. Again, the best way to prevent this is to use distilled
water in your antifreeze mix. It should also be changed at least every other
year. This is when the store bought flushing kits can be a small benefit.

Chris

c

"Richard M. Hinchliffe" <hinchlif@neuro.usc.edu> wrote in message
news:d3dde951.0310211843.31ef7ae5@posting.google.c om...
> "JimG" <jimg@cj7.com> wrote in message
news:<gQdlb.13195$Qx7.6514@news01.roc.ny>...
> > > I just change the thermostat hoping to fix the
> > > problem but still having the same issue.
> >
> > Yep, the thermostat would control how hot your heater might get, but
would
> > not keep it from producing some kind of heat.
> >
> > > I think that there is either a clog or air lock
> >
> > Yep, could even be a bad heater core.
> >
> > > I was thinking of flushing the system but have
> > > never done that on this vehicle before.
> >
> > No time to learn like the present. Your local auto store sells flush
kits
> > with directions.
> >
>
>
> With a flush kit, won't the water just take the path of least
> resistance? Going out the other end (radiator) and not unplugging
> the heater core?
> If the heater core is plugged wouldn't you need to put your hose right
> up to the heater core inlet?
> RMH

OK, I need to chime in here (again). The flushing kits you can buy in the
stores are just about useless. they will remove the sludge and crud that is
laying in the radiator or heater core, but they do nothing to remove the
calcium and mineral deposits in these things. If you can't get water to flow
through the heater core, just replace it. the core openings are so much
smaller than a radiator core and they will scale up faster than a radiator.
The radiator shops use a very diluted muriatic acid solution to attempt to
remove the scale with the core or radiator removed from the vehicle, but the
success rate is low. Again, the best way to prevent this is to use distilled
water in your antifreeze mix. It should also be changed at least every other
year. This is when the store bought flushing kits can be a small benefit.

Chris

c

"Richard M. Hinchliffe" <hinchlif@neuro.usc.edu> wrote in message
news:d3dde951.0310211843.31ef7ae5@posting.google.c om...
> "JimG" <jimg@cj7.com> wrote in message
news:<gQdlb.13195$Qx7.6514@news01.roc.ny>...
> > > I just change the thermostat hoping to fix the
> > > problem but still having the same issue.
> >
> > Yep, the thermostat would control how hot your heater might get, but
would
> > not keep it from producing some kind of heat.
> >
> > > I think that there is either a clog or air lock
> >
> > Yep, could even be a bad heater core.
> >
> > > I was thinking of flushing the system but have
> > > never done that on this vehicle before.
> >
> > No time to learn like the present. Your local auto store sells flush
kits
> > with directions.
> >
>
>
> With a flush kit, won't the water just take the path of least
> resistance? Going out the other end (radiator) and not unplugging
> the heater core?
> If the heater core is plugged wouldn't you need to put your hose right
> up to the heater core inlet?
> RMH

OK, I need to chime in here (again). The flushing kits you can buy in the
stores are just about useless. they will remove the sludge and crud that is
laying in the radiator or heater core, but they do nothing to remove the
calcium and mineral deposits in these things. If you can't get water to flow
through the heater core, just replace it. the core openings are so much
smaller than a radiator core and they will scale up faster than a radiator.
The radiator shops use a very diluted muriatic acid solution to attempt to
remove the scale with the core or radiator removed from the vehicle, but the
success rate is low. Again, the best way to prevent this is to use distilled
water in your antifreeze mix. It should also be changed at least every other
year. This is when the store bought flushing kits can be a small benefit.

Chris

Mike Romain

"Richard M. Hinchliffe" wrote:
>
> "JimG" <jimg@cj7.com> wrote in message news:<gQdlb.13195$Qx7.6514@news01.roc.ny>...
> > > I just change the thermostat hoping to fix the
> > > problem but still having the same issue.
> >
> > Yep, the thermostat would control how hot your heater might get, but would
> > not keep it from producing some kind of heat.
> >
> > > I think that there is either a clog or air lock
> >
> > Yep, could even be a bad heater core.
> >
> > > I was thinking of flushing the system but have
> > > never done that on this vehicle before.
> >
> > No time to learn like the present. Your local auto store sells flush kits
> > with directions.
> >
>
> With a flush kit, won't the water just take the path of least
> resistance? Going out the other end (radiator) and not unplugging
> the heater core?
> If the heater core is plugged wouldn't you need to put your hose right
> up to the heater core inlet?
> RMH

Yes, preferably the outlet though so you can back flush it.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's