FIXED: Little to no cabin heat 1998 Grand Cherokee

Inlet hose to firewall VERY HOT.... outlet hose from firewall COOL.. Pulled off both hoses at the front of engine and blew compressed air 1st in one hose (dumping the gunk out) then reversed and used a funnel to pour in WARM water then forced the compressed air the other direction (hose). Cabin nice and toasty now !

Also note there is a VERY THIN vacuum "T" just to the right of the engine coolant overflow bottle. If this comes loose, you lose the ability to choose where air comes from inside the cabin. Just an FYI if this happens to you.

On Mon, 27 Jan 2014 08:59:05 -0800 (PST), ndccpf1 >
wrote:
> Inlet hose to firewall VERY HOT.... outlet hose from firewall
COOL.. Pulled=
> off both hoses at the front of engine and blew compressed air 1st
in one h=
> ose (dumping the gunk out) then reversed and used a funnel to pour
in WARM =
> water then forced the compressed air the other direction (hose).
Cabin nice=
> and toasty now !


> Also note there is a VERY THIN vacuum "T" just to the right of the
engine c=
> oolant overflow bottle. If this comes loose, you lose the ability
to choose=
> where air comes from inside the cabin. Just an FYI if this happens
to you.

Yep, that heater core can build up a lot of crud over the years.
Especially if at any time the system has had any anti-leak stuff put
in it
or if the local area has hard water. My 93 still can drive me out of
the cabin.

It is a good idea to check all the hoses and hard-lines, they seem to
develop cracks about the same time.

DougW wrote:

> Yep, that heater core can build up a lot of crud over the years.
> Especially if at any time the system has had any anti-leak stuff put
> in it
> or if the local area has hard water. My 93 still can drive me out of
> the cabin.
>
> It is a good idea to check all the hoses and hard-lines, they seem to
> develop cracks about the same time.
>

I'm "lucky" enough to have an 88 MJ with the !@#$%^ closed coolant system.
On that one I can run a water hose in one side (bypass the vacuum valve!)
and out to a short dump hose on the other. Amazing how much crud comes out
if I do it once every couple of years!

Be careful with any of the pressure cleaning methods. The flow is what does
the work and you risk rupturing the heater core with anything over 20-25 psi
whether it's water or air pressure. My street-side water pressure is right
at 90 psi and I recall seeing one guy hook his heater up and just crank the
water wide open with that kind of pressure. Talk about a mess...

--
Will Honea

Doug,

My ex managed to get a leak in a freeze plug of the 72 Charger (400/ 2bbl,
T-Flite, 3.23 axle) we had and one of her boyfriends (yep, now you know why
she's my "ex") dumped some stop leak in.

I ended up recoring the radiator, replacing the freeze plug and the heater
core.

And she got the car in the divorce.

Will,

Check with Jeg's and Speedway and you can convert your system to an open
type and probably eliminate overheating or get a 98 radiator which has a
pressure cap.

I converted it on my son's 88 XJ with Speedway parts back when I had it and
will be doing it, probably with a junk yard radiator, on my 89 before I get
the AC converted to R134.

The 88 runs the mechanical fan only with no AC condenser in front of the
radiator and hasn't overheated in 100+ degree heat.

--
Budd Cochran

Need proof that we need less government?

They can't run a website that could have

been built with WYSIWYG5!


"Will Honea" > wrote in message
...
: DougW wrote:
:
: > Yep, that heater core can build up a lot of crud over the years.
: > Especially if at any time the system has had any anti-leak stuff put
: > in it
: > or if the local area has hard water. My 93 still can drive me out of
: > the cabin.
: >
: > It is a good idea to check all the hoses and hard-lines, they seem to
: > develop cracks about the same time.
: >
:
: I'm "lucky" enough to have an 88 MJ with the !@#$%^ closed coolant system.
: On that one I can run a water hose in one side (bypass the vacuum valve!)
: and out to a short dump hose on the other. Amazing how much crud comes
out
: if I do it once every couple of years!
:
: Be careful with any of the pressure cleaning methods. The flow is what
does
: the work and you risk rupturing the heater core with anything over 20-25
psi
: whether it's water or air pressure. My street-side water pressure is
right
: at 90 psi and I recall seeing one guy hook his heater up and just crank
the
: water wide open with that kind of pressure. Talk about a mess...
:
: --
: Will Honea
:



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Budd Cochran wrote:

> Check with Jeg's and Speedway and you can convert your system to an open
> type and probably eliminate overheating or get a 98 radiator which has a
> pressure cap.
>
> I converted it on my son's 88 XJ with Speedway parts back when I had it
> and will be doing it, probably with a junk yard radiator, on my 89 before
> I get the AC converted to R134.
>
> The 88 runs the mechanical fan only with no AC condenser in front of the
> radiator and hasn't overheated in 100+ degree heat.
>

I rebuilt the AC on mine - it has the aux electric fan - and made something
like 15 trips to South Texas in the summer a few years back. It got warm
just going up Ute Pass before the first trip as I hadn't flushed the
radiator in several years but once I flush out the crud it ran just fine in
110 degree sunshine with the closed system. I did turn an adapter on the
lathe to replace that crappy plastic cap that came on the bottle. That got
me a brass screw on adapter with a standard cap on it - the plastic one
wasn't holding pressure. That solved the heating problem.

I had to completely rebuild the compressor to get R134 to work with mine,
BTW. Gaskets + separator + lube ran me something like $45.

--
Will Honea

"Will Honea" > wrote in message
...
: Budd Cochran wrote:
:
: > Check with Jeg's and Speedway and you can convert your system to an open
: > type and probably eliminate overheating or get a 98 radiator which has a
: > pressure cap.
: >
: > I converted it on my son's 88 XJ with Speedway parts back when I had it
: > and will be doing it, probably with a junk yard radiator, on my 89
before
: > I get the AC converted to R134.
: >
: > The 88 runs the mechanical fan only with no AC condenser in front of the
: > radiator and hasn't overheated in 100+ degree heat.
: >
:
: I rebuilt the AC on mine - it has the aux electric fan - and made
something
: like 15 trips to South Texas in the summer a few years back. It got warm
: just going up Ute Pass before the first trip as I hadn't flushed the
: radiator in several years but once I flush out the crud it ran just fine
in
: 110 degree sunshine with the closed system. I did turn an adapter on the
: lathe to replace that crappy plastic cap that came on the bottle. That
got
: me a brass screw on adapter with a standard cap on it - the plastic one
: wasn't holding pressure. That solved the heating problem.

My closed system pressure cap on the 89 isn't holding well anymore and it's
only 3 years old!

Which is why I'm doing the conversion.

On the 88's open system, I removed the pressure cap innards and refit the
bottle as my overflow tank.

The closed system seems, from what I've read, very sensitive to anything not
within specs while an open system is far more dependable.
:
: I had to completely rebuild the compressor to get R134 to work with mine,
: BTW. Gaskets + separator + lube ran me something like $45.

Where did you find them? I can do the rebuild and my middle son is
automotive AC certified.
:
: --
: Will Honea
:



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Budd Cochran wrote:

> Where did you find them? I can do the rebuild and my middle son is
> automotive AC certified.
>

I found an outfit down in Phoenix that carried all the parts. Take the
compressor model you have and do a Google search on "J(xxxx) compressor
parts". Quicker than me looking it up ;-) but holler if you can't find them
and I'll dredge thru old emails for it.

BTW, I also found a compatible compressor in the junk yard complete with
what looked like new hoses and fittings. Guys want $40 for the whole thing
but my old one was working like a champ until a hose split so I passed.
Just make sure the compressor rotates freely with no grinding you can feel
if you go that way.

--
Will Honea

"Will Honea" > wrote in message
...
: Budd Cochran wrote:
:
: > Where did you find them? I can do the rebuild and my middle son is
: > automotive AC certified.
: >
:
: I found an outfit down in Phoenix that carried all the parts. Take the
: compressor model you have and do a Google search on "J(xxxx) compressor
: parts". Quicker than me looking it up ;-) but holler if you can't find
them
: and I'll dredge thru old emails for it.
:
: BTW, I also found a compatible compressor in the junk yard complete with
: what looked like new hoses and fittings. Guys want $40 for the whole
thing
: but my old one was working like a champ until a hose split so I passed.
: Just make sure the compressor rotates freely with no grinding you can feel
: if you go that way.
:
: --
: Will Honea
:
I'll check it out as soon as I can see something other than white stuff on
the ground, which I didn't order, btw.

I like rain ... you don't have to shovel it.


--
Budd Cochran

Need proof that we need less government?

They can't run a website that could have

been built with WYSIWYG5!



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Budd Cochran wrote:

> I'll check it out as soon as I can see something other than white stuff on
> the ground, which I didn't order, btw.
>
> I like rain ... you don't have to shovel it.
>

This recent weather is starting to look more like what I grew used to in the
years I spent up here in the 60's thru the 90's - if you don't like the
weather wait 20 minutes and it will change. You may recall that last summer
we had floods here after a 10 year drought - Ft. Carson had one 24 hour
total of nearly 12 inches OF RAIN! Tomorrow's high temp is forecast to be 6
degrees. I need an oil change but that will have to wait for the thaw just
like yours.

If you are planning ac work and don't have the gauge manifold, watch the
Harbor Freight adds - they have a pretty good one at the best price I've
seen. I a cheapy little compressor to pull a usable vacuum since the air
here is usually dry enough that you don't need the long pumpdown to clear
the system like we did in Texas. A 28 inch vacuum held 4-5 hours is more
than enough while the Gulf coast usually needed a hard 29 inches for 12
hours or more once the system had been opened.

--
Will Honea

"Will Honea" > wrote in message
...
: Budd Cochran wrote:
:
: > I'll check it out as soon as I can see something other than white stuff
on
: > the ground, which I didn't order, btw.
: >
: > I like rain ... you don't have to shovel it.
: >
:
: This recent weather is starting to look more like what I grew used to in
the
: years I spent up here in the 60's thru the 90's - if you don't like the
: weather wait 20 minutes and it will change. You may recall that last
summer
: we had floods here after a 10 year drought - Ft. Carson had one 24 hour
: total of nearly 12 inches OF RAIN! Tomorrow's high temp is forecast to be
6
: degrees. I need an oil change but that will have to wait for the thaw
just
: like yours.
:
: If you are planning ac work and don't have the gauge manifold, watch the
: Harbor Freight adds - they have a pretty good one at the best price I've
: seen. I a cheapy little compressor to pull a usable vacuum since the air
: here is usually dry enough that you don't need the long pumpdown to clear
: the system like we did in Texas. A 28 inch vacuum held 4-5 hours is more
: than enough while the Gulf coast usually needed a hard 29 inches for 12
: hours or more once the system had been opened.
:
: --
: Will Honea

Hmmm ... I have this little 12V compressor that will pump up 60 psi pretty
quick maybe I'll see what vacuum it'll pull.

Harbor Freight is fine as long as you don't buy the super cheap stuff.

Go up a price level or two and you usually get pretty good stuff.

We're going to see about the same high as you but we're both in the
foothills.

But sometimes this cozy little valley stays warmer than the rest of the
state ... which is why the Native Americans loved it for wintering.

<VBG>


--
Budd Cochran

Need proof that we need less government?

They can't run a website that could have

been built with WYSIWYG5!



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