Jeep: Intermittant problem

For what it's worth, my '96 Cherokee with the 195 F thermostat often creeps
over the the 100 C mark (hot day in traffic, pulling the boat in traffic,
.... ) at which point the electric fan comes on, all of which is normal, my
understanding. Not familiar with the '93 but could that be what you describe
as "begins to overheat"? I also understand that the blades on the waterpump
may deteriorate with time giving a pump that works, but not as well as it
used to, especially at idle causing overheating.
 

On Fri, 08 Jul 2005 03:10:51 GMT, "YouGoFirst"
<com> wrote:
 

Under what specific conditions does it start to overheat and how hot
does it get? (if you don't have a gauge in the thing - go get one!)

A good, professional flushing of the radiator may be in order as I
once had thermostat gasket material break loose and really plug up a
radiator.

Also, I'm not too familiar with the location of the thermometer in the
V-8 model but I know on the I6 if you don't drill a tiny hole in the
top edge of the thermostat you can get trapped air around the
thermostat's "pellet" and it will open too late on a regular basis
causing an overheat condition. Even if you don't have that design you
may still have trapped air somewhere causing trouble.

I would check that viscous clutch too. The easiest way I've found is
to drive the vehicle until it's warm, pop the hood and watch the
clutch/fan and turn the engine off (or have someone else do it). The
fan should pretty much jerk to a halt with the engine, not continue
coasting.

Also is your aux fan coming on when it should?


Drifter
"I've been here, I've been there..."

> Under what specific conditions does it start to overheat and how hot 

It almost redlined the first time. The next time, I was driving on the
freeway, so it didn't get as hot. But, once I stopped, the temperature
crept up higher than normal and boiled out a little bit of fluid.
 

I don't think that is the problem, the thermostat and gasket were replaced
less than 2 weeks ago. I would expect a blockage to cause a consistent
problem.
 

Since that is a regular problem, I don't think that is what is going on. My
problem seems to be random. The day after the first time I took my car into
the dealership, and they couldn't get it to overheat.
 

That sounds simple enough. If it is the viscous clutch, should I be able to
easily turn it by hand, or should it be relatively stiff? Do you know of
any other checks to make sure that the viscous clutch is working properly,
or do you know about how long one should last.
 

Aux fan? I don't think I have an aux fan. Do they cost much, and are they
hard to install?

"Bowgus" <com> wrote in message
news:com... 

I don't think it is the water pump because I had the dealership take a look
at it a couple of weeks ago when I wasn't sure if my water pump was gone or
if the thermostat was gone. They said that they checked it out and the
water pump was fine.

I guess I should have clarified the overheating better. If I was to sit and
idle, my car would have overheated, but since I was moving, and didn't let
it get too hot before shutting down it didn't.

"YouGoFirst" <com> wrote in message
news:29wze.400364$ops.worldnet.att.net...
 

My guess if this did not happen at all before the thermostat was replaced is
that you could have a defective thermostat installed now. Maybe opens at
the wrong temperature; maybe it sticks. It happens. This is using the
logic of what is different now than before.
Hope this might help,
Tomes

"Tomes" <net> wrote in message
news:Gkzze.6558$news.atl.earthlink.net... 

I have never heard of a thermostat sticking. Is that something that will
eventually be "broken in" and stop sticking? I would think that if it was
sticking, it would show up consistantly, not randomly. Since I have never
seen or heard of that I don't know for sure.

"YouGoFirst" <com> wrote in message
news:kBzze.1104041$ops.worldnet.att.net... 
replaced 
at 

It is one of those fluke in the universe things, but I had it happen to me
once a while ago. These things are mass-produced and they can't all be
perfect. Don't know if it would clear up on its own. Think of a door that
sticks sometimes and other times does not. I swapped in a new one then (it
was easy on that car) and all was then fine. You might want to try it as an
easy attempt at fixing it.

"Tomes" <net> wrote in message
news:GVDze.19679$news.atl.earthlink.net...

<snip>

In the meantime, don't let your engine overheat. When it begins to
overheat, kick on the heater full blast and see if the temperature goes
down. If it does, you have water circulating. If it doesn't, you don't. I
know it sucks in the summer but just roll the windows down and sweat a bit.

-Bill