98 Grand Cherokee 4.0 Overheating Problem

On Tue, 2 Sep 2008 18:55:30 -0700 (PDT), PhilB >
wrote:


>This weekend I"ll change, or just remove the thermostat altogether.

That is the first step I would take, but if you are waiting for the
weekend don't drive the vehicle until then. You might get away with
one good overheat but don't press your luck,

>
>But....when I shut the car, I heard a hissing sound. Upon some
>exploration, it seems to be coming from below/behind the water pump,
>below the head. The hissing sound continued for awhile after the car
>was shut down, like something was depressurizing or re-pressurizing.
>
Probably just the a/c. Keep an eye on the water level once you start
driving it just to be sure.

>Anyone recommend a shop on the east coast specializing in Jeep
>rebuilds....if I'm gonna do the head, I may as well have the entire
>thing looked after I suppose.
>
You are being courted by the she devil known as "might as well".
Might as well will cost you a fortune on a job like this if you don't
keep her in check. Doing the top end, might as well do the bottom
end. Cooling system is open, might as well replace the radiator and
water pump and all the hoses. Look at all these old rubber lines,
might as well replace them all. Watch out for this temptress...

Steve B.

PhilB wrote:
> Let's just say it's the head gasket. I haven't done that much work on
> a motor since I tore down a Boss 302 Ford engine when I was a teenager
> (not a very long time ago but long enough). I learned a lot, but I
> also had a summer full of time, no job, house, wife, kids, etc.
>
> I assume given the vehicle is a 1998 with 160,000+/- miles on it, it
> wouldn't make sense to have the dealer perform the operation as the
> cost would be prohibitive. I assume the local service station would
> be costly as well. Is it feasible to change the head gasket (and I
> assume recondition the head while I'm at it) in my own garage? Are
> there special tools or techniques needed, or is this just the removal
> and re installation of a lot of parts?
>

You couldn't ask for an engine that's much easier to do a head gasket on
than a Jeep 4.0. Fortunately both the head and block are cast iron, so
its much more tolerant of overheating than an all-aluminum or and
aluminum-headed engine.

The most sophisticated tool it would require is a torque wrench.

On Sep 3, 10:31*am, Steve B. > wrote:
> On Tue, 2 Sep 2008 18:55:30 -0700 (PDT), PhilB >
> wrote:
>
> >This weekend I"ll change, or just remove the thermostat altogether.
>
> That is the first step I would take, but if you are waiting for the
> weekend don't drive the vehicle until then. *You might get away with
> one good overheat but don't press your luck,
>
>
>
> >But....when I shut the car, I heard a hissing sound. *Upon some
> >exploration, it seems to be coming from below/behind the water pump,
> >below the head. *The hissing sound continued for awhile after the car
> >was shut down, like something was depressurizing or re-pressurizing.
>
> Probably just the a/c. *Keep an eye on the water level once you start
> driving it just to be sure.
>
> >Anyone recommend a shop on the east coast specializing in Jeep
> >rebuilds....if I'm gonna do the head, I may as well have the entire
> >thing looked after I suppose.
>
> You are being courted *by the she devil known as "might as well".
> Might as well will cost you a fortune on a job like this if you don't
> keep her in check. *Doing the top end, might as well do the bottom
> end. *Cooling system is open, might as well replace the radiator and
> water pump and all the hoses. Look at all these old rubber lines,
> might as well replace them all. *Watch out for this temptress...
>
> * * * * * * Steve B.

Ok, we seem to be good. The hissing was the a/c. The overheating was
the thermo, I removed it this evening, I had another gasket on hand
but not another thermo, so I just pulled the thermo out, cleaned the
goose neck, re-gasketed and put the goose neck back on. Ran it for
20 minutes or so and everything was cool. We'll see what the next few
days bring.

Thermo was only a year old, and very rusted. Don't understand why, I
run with 100% Prestone, no water. So I'm sure there are other
issues. Still weighing my options with this Jeep.

Thanks everyone for your help, and encouragement.

Phil

hey Phil you live in an area that gets cold in the winter? and if you do ,
do you run straight anti-freeze in the winter as well?




"PhilB" > wrote in message
...
On Sep 3, 10:31 am, Steve B. > wrote:
> On Tue, 2 Sep 2008 18:55:30 -0700 (PDT), PhilB >
> wrote:
>
> >This weekend I"ll change, or just remove the thermostat altogether.
>
> That is the first step I would take, but if you are waiting for the
> weekend don't drive the vehicle until then. You might get away with
> one good overheat but don't press your luck,
>
>
>
> >But....when I shut the car, I heard a hissing sound. Upon some
> >exploration, it seems to be coming from below/behind the water pump,
> >below the head. The hissing sound continued for awhile after the car
> >was shut down, like something was depressurizing or re-pressurizing.
>
> Probably just the a/c. Keep an eye on the water level once you start
> driving it just to be sure.
>
> >Anyone recommend a shop on the east coast specializing in Jeep
> >rebuilds....if I'm gonna do the head, I may as well have the entire
> >thing looked after I suppose.
>
> You are being courted by the she devil known as "might as well".
> Might as well will cost you a fortune on a job like this if you don't
> keep her in check. Doing the top end, might as well do the bottom
> end. Cooling system is open, might as well replace the radiator and
> water pump and all the hoses. Look at all these old rubber lines,
> might as well replace them all. Watch out for this temptress...
>
> Steve B.

Ok, we seem to be good. The hissing was the a/c. The overheating was
the thermo, I removed it this evening, I had another gasket on hand
but not another thermo, so I just pulled the thermo out, cleaned the
goose neck, re-gasketed and put the goose neck back on. Ran it for
20 minutes or so and everything was cool. We'll see what the next few
days bring.

Thermo was only a year old, and very rusted. Don't understand why, I
run with 100% Prestone, no water. So I'm sure there are other
issues. Still weighing my options with this Jeep.

Thanks everyone for your help, and encouragement.

Phil

On Sep 6, 7:04*am, "rob" > wrote:
> hey Phil you live in an area that gets cold in the winter? and if you do ,
> do you run straight anti-freeze in the winter as well?

Yes, NYC - freeze/thaw. I run straight anti freeze winter/summer.
Although, come to think of it, the Prestone container I think says "do
not add water, 50/50 mix". I have to check, I may be confusing it in
my mind with the coolant I use for another car.

Thanks.

On Sat, 6 Sep 2008 06:19:05 -0700 (PDT), PhilB >
wrote:

>On Sep 6, 7:04*am, "rob" > wrote:
>> hey Phil you live in an area that gets cold in the winter? and if you do ,
>> do you run straight anti-freeze in the winter as well?
>
>Yes, NYC - freeze/thaw. I run straight anti freeze winter/summer.
>Although, come to think of it, the Prestone container I think says "do
>not add water, 50/50 mix". I have to check, I may be confusing it in
>my mind with the coolant I use for another car.
>
>Thanks.

You shouldn't run antifreeze any higher than a 70/30 ratio. 50/50
gives you protection to -34. 70/30 gives you protection to -84.
Straight antifreeze freezes at -8 and it doesn't carry away the heat
as well as properly mixed antifreeze which can cause overheating
problems.

Steve B.

phil, not having a thermostat in it my really hurt your fuel milage .
computer thinks it s cold all the time and runs rich

----------------------------------------------------------------
http://www.minibite.com/america/malone.htm

On Sep 6, 9:05*pm, wrote:
> * phil, not having a thermostat in it my really hurt your fuel milage .
> computer thinks it s cold all the time and runs rich
>
> ----------------------------------------------------------------http://www.minibite.com/america/malone.htm


Thanks, intend on putting a new thermo in, just didn't have one on
hand to run this test. It's a PIA to change with that fan shroud in
the way, but if I keep the Jeep I need to do plugs, oil etc, so I'll
deal with it all in one sitting.

Thanks.

On Sep 6, 10:59*am, Steve B. > wrote:
> On Sat, 6 Sep 2008 06:19:05 -0700 (PDT), PhilB >
> wrote:
>
> >On Sep 6, 7:04*am, "rob" > wrote:
> >> hey Phil you live in an area that gets cold in the winter? and if you do ,
> >> do you run straight anti-freeze in the winter as well?
>
> >Yes, NYC - freeze/thaw. *I run straight anti freeze winter/summer.
> >Although, come to think of it, the Prestone container I think says "do
> >not add water, 50/50 mix". *I have to check, I may be confusing it in
> >my mind with the coolant I use for another car.
>
> >Thanks.
>
> You shouldn't run antifreeze any higher than a 70/30 ratio. *50/50
> gives you protection to -34. *70/30 gives you protection to -84.
> Straight antifreeze freezes at -8 and *it doesn't carry away the heat
> as well as properly mixed antifreeze which can cause overheating
> problems.
>
> * * * * *Steve B.

Np. It's the 50/50 mix, I checked the container last night.. So I
think I'm covered. Am starting anew thread, went and took a new
Wrangler and Grand Cherokee for a test drive yesterday.....

Phil

PhilB wrote:

Don't understand why, I
> run with 100% Prestone, no water.

Why do that? You realize that straight glycol has significantly less
heat transfer capability than a 50/50 mix, don't you? And also the
corrosion inhibitors are intended to work WITH water, not without it.