low coolant

Hello,

I have a '96 Saturn with 120k on it. The coolant indicator light come
on and goes off intermittently. I had an OBD read and it reported a
problem stating something like "low coolant sensor". Is there a
sensor that monitors coolant level? If so, where is it--I don't see
anything in the overflow reservoir tub. This sensor obviously reports
back to the computer. Could this sensor error prevent the drive-cycle
from taking place. I disconnected my battery about 4 weeks/400mi ago
and my computer is reporting no codes which is preventing me from
getting an NYS (New York) inspection.

By the way, the temp sensor is working fine and the car does not
overheat.

Thank you for your help,
Rob

 

Rob,

You need to look closer. There is indeed a small sensor located in the
bottom of the plastic coolant reservoir. If it comes on intermittently,
then you are probably low on coolant and the solution is most likely to add
a 50 mix to get you to the full cold line.

It might also be a good time to flush and refill the system since this is
supposed to be done every two years. If you do, then remove the coolant
recovery reservoir and clean it thoroughly with hot soapy water. Make sure
you also use the correct coolant (Saturn's use special coolant) and add the
2 crushed leak-stop pellets as well. The coolant and pellets are available
from the dealer.

Bob

 

Thank you for the tip. You're are correct I didn't look that closely. I
plan to remove the reservoir tank and do a more thorough search. The level
in the reservoir is fine, it reads properly for both the cold and hot
levels. Flushing it also a good suggestion. Perhaps the sensor is bad or a
dirty reservoir is preventing proper operation.

Would this flaky sensor prevent a drive cycle from taking place, thus
preventing the computer from generating codes. I disconnected the battery a
while ago and the state's NYS inspection computer is telling my mechanic
that there are no codes to report. He told me to drive the car for a while
to get the computer to generate codes. I've driven the car for 4
wks/400miles and the computer is still in the same state.

 

You should also check the wires going from the sensor all the way to the
harness.

When my Saturn started flashing the low coolant indicator it turned out
to be that the sensor wires had been chewed up. I fixed it, and then it
did it again. It appears that a small animal out here favors yellow wires.

Now I park the Saturn in my garage.


JM

 

It is dependent on the number of ignition (starts) cycles. I think it
requires 40 or 50 cycles to turn off/reset that history flag.

Good luck.

Bob

 

I am not sure about the Saturn, but other GM cars requires the eng
temp to raise more than 40° before it considers one ignition cycle
completed. GM dealers have a proceedure to follow, to reset the
history so it will pass inspections.

James