> Overheating In Traffic (Stop and Go, Low Speed Driving)
> Overheating in traffic and low speed driving has one common cause: the
> fan. During stop and go, low speed "creeping" and low speed driving, there
> is not sufficient flow of air through the radiator. Therefore, the engine
> has a fan to draw air through the front of the car. This fan operates off
> of a viscous fan clutch. Basically, the fan clutch is mounted between the
> fan and the engine. As cold air flows over it, the clutch loosens up,
> allowing the fan to freewheel on the shaft of the engine. The fan then
> hardly turns. As the air flowing over the clutch heats up (as the engine
> transfers more heat to the radiator) the clutch tightens up, spinning the
> fan faster and drawing more air through the radiator. The cycle continues
> as long as the car is running. Over time, this fan clutch can wear out,
> causing the fan to freewheel whether it is hot or cold. This causes
> reduced airflow through the radiator, and therefore high operating
> temperatures during low speed driving. This theory is easy to test,
> because once you get on the highway the car will cool right down.
> Testing the fan clutch is pretty easy. Simply start the car and allow it
> to warm up to normal operating temperature. Shut it off, then give the fan
> a good flick with your hand. If it rotates more than about 1.5 turns, then
> odds are the fan clutch is worn. However, I have found this test to be a
> very bad indicator of the true condition of the clutch. A much better test
> is to simply pick another one up and swap it on. If this solves your
> problem, then the fan clutch was obviously the culprit.
>

I took it in to the place where I had the fan clutch replaced, and the owner
said that he has owned several Jeep Grand Cherokees, and that they all run
hot. He said that as long as I am not getting above the 235 mark I should
be ok. Is there anybody out there who has owned a 1993 V8 Jeep Grand
Cherokee that can confirm that it can get that hot when running the AC while
it is 100 degrees outside?

 

I can confirm it though not a 1993 - I have the 1997 w/ v8 - was the next
notch up last week while driving in 90+ heat a little over 100 w/ heat index
in stop and go Philly driving for about 3 hours. I was worried for a bit,
since the all the xj(s) I've owned never went above 210 (unless you count
when the electric fan went)... but it never went above the next notch, just
stayed there all day...

Paul

> I took it in to the place where I had the fan clutch replaced, and the
> owner said that he has owned several Jeep Grand Cherokees, and that they
> all run hot. He said that as long as I am not getting above the 235 mark
> I should be ok. Is there anybody out there who has owned a 1993 V8 Jeep
> Grand Cherokee that can confirm that it can get that hot when running the
> AC while it is 100 degrees outside?
>

 

I can confirm it though not a 1993 - I have the 1997 w/ v8 - was the next
notch up last week while driving in 90+ heat a little over 100 w/ heat index
in stop and go Philly driving for about 3 hours. I was worried for a bit,
since the all the xj(s) I've owned never went above 210 (unless you count
when the electric fan went)... but it never went above the next notch, just
stayed there all day...

Paul

> I took it in to the place where I had the fan clutch replaced, and the
> owner said that he has owned several Jeep Grand Cherokees, and that they
> all run hot. He said that as long as I am not getting above the 235 mark
> I should be ok. Is there anybody out there who has owned a 1993 V8 Jeep
> Grand Cherokee that can confirm that it can get that hot when running the
> AC while it is 100 degrees outside?
>

 

I can confirm it though not a 1993 - I have the 1997 w/ v8 - was the next
notch up last week while driving in 90+ heat a little over 100 w/ heat index
in stop and go Philly driving for about 3 hours. I was worried for a bit,
since the all the xj(s) I've owned never went above 210 (unless you count
when the electric fan went)... but it never went above the next notch, just
stayed there all day...

Paul

> I took it in to the place where I had the fan clutch replaced, and the
> owner said that he has owned several Jeep Grand Cherokees, and that they
> all run hot. He said that as long as I am not getting above the 235 mark
> I should be ok. Is there anybody out there who has owned a 1993 V8 Jeep
> Grand Cherokee that can confirm that it can get that hot when running the
> AC while it is 100 degrees outside?
>

 

I can confirm it though not a 1993 - I have the 1997 w/ v8 - was the next
notch up last week while driving in 90+ heat a little over 100 w/ heat index
in stop and go Philly driving for about 3 hours. I was worried for a bit,
since the all the xj(s) I've owned never went above 210 (unless you count
when the electric fan went)... but it never went above the next notch, just
stayed there all day...

Paul

> I took it in to the place where I had the fan clutch replaced, and the
> owner said that he has owned several Jeep Grand Cherokees, and that they
> all run hot. He said that as long as I am not getting above the 235 mark
> I should be ok. Is there anybody out there who has owned a 1993 V8 Jeep
> Grand Cherokee that can confirm that it can get that hot when running the
> AC while it is 100 degrees outside?
>

 

On Fri, 22 Jul 2005 14:10:34 GMT, "YouGoFirst"
<yougofirst@hotmail.com> wrote:

>I took it in to the place where I had the fan clutch replaced, and the owner
>said that he has owned several Jeep Grand Cherokees, and that they all run
>hot. He said that as long as I am not getting above the 235 mark I should
>be ok. Is there anybody out there who has owned a 1993 V8 Jeep Grand
>Cherokee that can confirm that it can get that hot when running the AC while
>it is 100 degrees outside?
>

We have a '93 JGC Limited with 90,000 miles. With ambient running 100
to 105 lately, the Jeep runs at almost 210 degrees while moving at
least 40 mph. If I do a lot of stop and go driving, it will go over
the 210 mark. I let it sit and idle yesterday for about 10 minutes
with my wife in the car, and when I returned it was just below the red
line. As soon as I got the car moving above 40 mph, it came back down
to 210. My thermostat is less than 6-months old. Original water
pump. Seems like it has always run pretty hot. I have had to turn
the A/C off when in Phoenix at about 115F. The engine pinged so back
I thought it would blow up. Turning off the A/C stopped the pinging,
but darn near melted us.

----

 

On Fri, 22 Jul 2005 14:10:34 GMT, "YouGoFirst"
<yougofirst@hotmail.com> wrote:

>I took it in to the place where I had the fan clutch replaced, and the owner
>said that he has owned several Jeep Grand Cherokees, and that they all run
>hot. He said that as long as I am not getting above the 235 mark I should
>be ok. Is there anybody out there who has owned a 1993 V8 Jeep Grand
>Cherokee that can confirm that it can get that hot when running the AC while
>it is 100 degrees outside?
>

We have a '93 JGC Limited with 90,000 miles. With ambient running 100
to 105 lately, the Jeep runs at almost 210 degrees while moving at
least 40 mph. If I do a lot of stop and go driving, it will go over
the 210 mark. I let it sit and idle yesterday for about 10 minutes
with my wife in the car, and when I returned it was just below the red
line. As soon as I got the car moving above 40 mph, it came back down
to 210. My thermostat is less than 6-months old. Original water
pump. Seems like it has always run pretty hot. I have had to turn
the A/C off when in Phoenix at about 115F. The engine pinged so back
I thought it would blow up. Turning off the A/C stopped the pinging,
but darn near melted us.

----

 

On Fri, 22 Jul 2005 14:10:34 GMT, "YouGoFirst"
<yougofirst@hotmail.com> wrote:

>I took it in to the place where I had the fan clutch replaced, and the owner
>said that he has owned several Jeep Grand Cherokees, and that they all run
>hot. He said that as long as I am not getting above the 235 mark I should
>be ok. Is there anybody out there who has owned a 1993 V8 Jeep Grand
>Cherokee that can confirm that it can get that hot when running the AC while
>it is 100 degrees outside?
>

We have a '93 JGC Limited with 90,000 miles. With ambient running 100
to 105 lately, the Jeep runs at almost 210 degrees while moving at
least 40 mph. If I do a lot of stop and go driving, it will go over
the 210 mark. I let it sit and idle yesterday for about 10 minutes
with my wife in the car, and when I returned it was just below the red
line. As soon as I got the car moving above 40 mph, it came back down
to 210. My thermostat is less than 6-months old. Original water
pump. Seems like it has always run pretty hot. I have had to turn
the A/C off when in Phoenix at about 115F. The engine pinged so back
I thought it would blow up. Turning off the A/C stopped the pinging,
but darn near melted us.

----

 

On Fri, 22 Jul 2005 14:10:34 GMT, "YouGoFirst"
<yougofirst@hotmail.com> wrote:

>I took it in to the place where I had the fan clutch replaced, and the owner
>said that he has owned several Jeep Grand Cherokees, and that they all run
>hot. He said that as long as I am not getting above the 235 mark I should
>be ok. Is there anybody out there who has owned a 1993 V8 Jeep Grand
>Cherokee that can confirm that it can get that hot when running the AC while
>it is 100 degrees outside?
>

We have a '93 JGC Limited with 90,000 miles. With ambient running 100
to 105 lately, the Jeep runs at almost 210 degrees while moving at
least 40 mph. If I do a lot of stop and go driving, it will go over
the 210 mark. I let it sit and idle yesterday for about 10 minutes
with my wife in the car, and when I returned it was just below the red
line. As soon as I got the car moving above 40 mph, it came back down
to 210. My thermostat is less than 6-months old. Original water
pump. Seems like it has always run pretty hot. I have had to turn
the A/C off when in Phoenix at about 115F. The engine pinged so back
I thought it would blow up. Turning off the A/C stopped the pinging,
but darn near melted us.

----

 

> We have a '93 JGC Limited with 90,000 miles. With ambient running 100
> to 105 lately, the Jeep runs at almost 210 degrees while moving at
> least 40 mph. If I do a lot of stop and go driving, it will go over
> the 210 mark. I let it sit and idle yesterday for about 10 minutes
> with my wife in the car, and when I returned it was just below the red
> line. As soon as I got the car moving above 40 mph, it came back down
> to 210. My thermostat is less than 6-months old. Original water
> pump. Seems like it has always run pretty hot. I have had to turn
> the A/C off when in Phoenix at about 115F. The engine pinged so back
> I thought it would blow up. Turning off the A/C stopped the pinging,
> but darn near melted us.
>

Thanks, I guess the mechanic wasn't full of crap.