googlegroups@gersic.com proclaimed:

>>IS there a layer of brownish red scum (or any other color) in the expansion
>>tank?
>
>
> No, but there was back when I bought the car. I flushed the coolant
> using one of those garden-hose adapter things, and cleaned the overflow
> tank about two years ago. I wouldn't eat off of it or anything now, but
> it's reasonably clean.
>

Connectors on the wiring to that sensor all crudded up?

 

googlegroups@gersic.com proclaimed:

>>IS there a layer of brownish red scum (or any other color) in the expansion
>>tank?
>
>
> No, but there was back when I bought the car. I flushed the coolant
> using one of those garden-hose adapter things, and cleaned the overflow
> tank about two years ago. I wouldn't eat off of it or anything now, but
> it's reasonably clean.
>

Connectors on the wiring to that sensor all crudded up?

 

googlegroups@gersic.com proclaimed:

>>IS there a layer of brownish red scum (or any other color) in the expansion
>>tank?
>
>
> No, but there was back when I bought the car. I flushed the coolant
> using one of those garden-hose adapter things, and cleaned the overflow
> tank about two years ago. I wouldn't eat off of it or anything now, but
> it's reasonably clean.
>

Connectors on the wiring to that sensor all crudded up?

 

The girl that owned the WJ before me allowed her quickie-lube to add
Prestone Universal (DexCool) to the system.

It turned the coolant into brownish red sludge

The sensor is pretty much a float but the float gets stuck when it is full
of sludge.


"Lon" <lon.stowell@comcast.net> wrote in message
news:WdOdndOAabAX2WHZnZ2dnUVZ_qidnZ2d@comcast.com. ..
> googlegroups@gersic.com proclaimed:
>
>>>IS there a layer of brownish red scum (or any other color) in the
>>>expansion
>>>tank?
>>
>>
>> No, but there was back when I bought the car. I flushed the coolant
>> using one of those garden-hose adapter things, and cleaned the overflow
>> tank about two years ago. I wouldn't eat off of it or anything now, but
>> it's reasonably clean.
>>
>
> Connectors on the wiring to that sensor all crudded up?

 

The girl that owned the WJ before me allowed her quickie-lube to add
Prestone Universal (DexCool) to the system.

It turned the coolant into brownish red sludge

The sensor is pretty much a float but the float gets stuck when it is full
of sludge.


"Lon" <lon.stowell@comcast.net> wrote in message
news:WdOdndOAabAX2WHZnZ2dnUVZ_qidnZ2d@comcast.com. ..
> googlegroups@gersic.com proclaimed:
>
>>>IS there a layer of brownish red scum (or any other color) in the
>>>expansion
>>>tank?
>>
>>
>> No, but there was back when I bought the car. I flushed the coolant
>> using one of those garden-hose adapter things, and cleaned the overflow
>> tank about two years ago. I wouldn't eat off of it or anything now, but
>> it's reasonably clean.
>>
>
> Connectors on the wiring to that sensor all crudded up?

 

The girl that owned the WJ before me allowed her quickie-lube to add
Prestone Universal (DexCool) to the system.

It turned the coolant into brownish red sludge

The sensor is pretty much a float but the float gets stuck when it is full
of sludge.


"Lon" <lon.stowell@comcast.net> wrote in message
news:WdOdndOAabAX2WHZnZ2dnUVZ_qidnZ2d@comcast.com. ..
> googlegroups@gersic.com proclaimed:
>
>>>IS there a layer of brownish red scum (or any other color) in the
>>>expansion
>>>tank?
>>
>>
>> No, but there was back when I bought the car. I flushed the coolant
>> using one of those garden-hose adapter things, and cleaned the overflow
>> tank about two years ago. I wouldn't eat off of it or anything now, but
>> it's reasonably clean.
>>
>
> Connectors on the wiring to that sensor all crudded up?

 

I would start by cleaning the plug and socket on it with a good spray
contact cleaner.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

googlegroups@gersic.com wrote:
>
> Hi All,
>
> I have a 1997 Jeep Grand Cherokee Laredo 4x4. For the last year or so,
> every so often (a few times a week), I get the message "Coolant Sensor
> Bad" in the center console (the area that shows "miles to service" and
> when doors are open and such). According to various sources, the
> coolant sensor in question is the coolant level sensor in the overflow
> tank. The other coolant sensor that is in the engine block throws a
> "check engine light" error code if it's having problems (I've verified
> that by unplugging it), so I'm reasonably certain that that's not the
> one causing the problem.
>
> Now, I'm sure most of you are thinking, "why don't you just replace the
> coolant level sensor?" I did that right away last year when it first
> started happening. It didn't have any affect on the problem whatsoever.
> I've also brought the car to the Jeep dealer, and surprise, surprise,
> it didn't happen while the car was there, so I got to pay the
> diagnostic fee and go home.
>
> One interesting thing is that the "coolant sensor bad" message didn't
> occur all winter, so it does appear to be affected--at least to some
> degree--by temperature.
>
> Anybody have any ideas on how either to fix the problem with the
> coolant sensor, or to at least get it to stop telling me about it? I
> don't particularly care if there's a problem with the coolant level
> sensor...I'm perfectly capable of lifting the hood to look at the
> overflow tank, but the beeping from the console is kind of annoying.
>
> Thanks,
> Tom

 

I would start by cleaning the plug and socket on it with a good spray
contact cleaner.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

googlegroups@gersic.com wrote:
>
> Hi All,
>
> I have a 1997 Jeep Grand Cherokee Laredo 4x4. For the last year or so,
> every so often (a few times a week), I get the message "Coolant Sensor
> Bad" in the center console (the area that shows "miles to service" and
> when doors are open and such). According to various sources, the
> coolant sensor in question is the coolant level sensor in the overflow
> tank. The other coolant sensor that is in the engine block throws a
> "check engine light" error code if it's having problems (I've verified
> that by unplugging it), so I'm reasonably certain that that's not the
> one causing the problem.
>
> Now, I'm sure most of you are thinking, "why don't you just replace the
> coolant level sensor?" I did that right away last year when it first
> started happening. It didn't have any affect on the problem whatsoever.
> I've also brought the car to the Jeep dealer, and surprise, surprise,
> it didn't happen while the car was there, so I got to pay the
> diagnostic fee and go home.
>
> One interesting thing is that the "coolant sensor bad" message didn't
> occur all winter, so it does appear to be affected--at least to some
> degree--by temperature.
>
> Anybody have any ideas on how either to fix the problem with the
> coolant sensor, or to at least get it to stop telling me about it? I
> don't particularly care if there's a problem with the coolant level
> sensor...I'm perfectly capable of lifting the hood to look at the
> overflow tank, but the beeping from the console is kind of annoying.
>
> Thanks,
> Tom

 

I would start by cleaning the plug and socket on it with a good spray
contact cleaner.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

googlegroups@gersic.com wrote:
>
> Hi All,
>
> I have a 1997 Jeep Grand Cherokee Laredo 4x4. For the last year or so,
> every so often (a few times a week), I get the message "Coolant Sensor
> Bad" in the center console (the area that shows "miles to service" and
> when doors are open and such). According to various sources, the
> coolant sensor in question is the coolant level sensor in the overflow
> tank. The other coolant sensor that is in the engine block throws a
> "check engine light" error code if it's having problems (I've verified
> that by unplugging it), so I'm reasonably certain that that's not the
> one causing the problem.
>
> Now, I'm sure most of you are thinking, "why don't you just replace the
> coolant level sensor?" I did that right away last year when it first
> started happening. It didn't have any affect on the problem whatsoever.
> I've also brought the car to the Jeep dealer, and surprise, surprise,
> it didn't happen while the car was there, so I got to pay the
> diagnostic fee and go home.
>
> One interesting thing is that the "coolant sensor bad" message didn't
> occur all winter, so it does appear to be affected--at least to some
> degree--by temperature.
>
> Anybody have any ideas on how either to fix the problem with the
> coolant sensor, or to at least get it to stop telling me about it? I
> don't particularly care if there's a problem with the coolant level
> sensor...I'm perfectly capable of lifting the hood to look at the
> overflow tank, but the beeping from the console is kind of annoying.
>
> Thanks,
> Tom