Coolant Reservoir and Coolant Light Fix 2003 Saturn Ion

I drive a 2003 Saturn Ion 3.  I'm not flashy and don't need to be.  Its paid for and I'm washed-up remember?

Over the past few years off and on I started noticing the Saturn going into a high idle on the first startup of the car.  This is pretty normal on cold mornings as the car idles high in order to warm itself.  When its the middle of the summer it does not need to high idle for entire commutes to and from work.

Summary:  Took the car to a shop with a reputable mechanic and he said the "temperature sensor" was pretty dirty which probably meant that the sensor was "gunked" up (his words) and not reading the temperature properly thus causing a high idle on the car.  He cleaned it off but not 3 months later it began happening again.

Along with the high idle problem we have been suffering, we started having the coolant light pop up on the dash every time the car is started.  I did some investigating and reading some of the Saturn forums.  It appears that Saturn or GM decided to build a coolant reservoir that has a sensor built inside of it that detects your coolant level.  When this sensor goes defective or begins acting up, the coolant light will start popping up as well.

After reading some success stories around the internet, I decided to attempt this myself.

Result: Coolant light has gone and the high idle went with it.

Parts:

AC Delco Temperature Coolant sensor: $9
http://www.amazon.com/dp/B001W0FSMM/ref=pe_175190_21431760_M3T1_SC_dp_1

AC Delco Coolant Reservior: $42.90
http://www.amazon.com/ACDelco-10368831-Radiator-Tank-Assembly/dp/B000K040LA/ref=sr_1_1?ie=UTF8&qid=1349145793&sr=8-1&keywords=ACDelco+10368831+Radiator

Hose clamp pliers: $33
http://www.amazon.com/OTC-4525-Cable-Type-Flexible-Pliers/dp/B000F5JM0O/ref=sr_1_1?ie=UTF8&qid=1349145896&sr=8-1&keywords=OTC+4525+Cable-Type+Flexible+Hose+Clamp+Pliers

Fluid Extractor: $5
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_battery-filler-1-piece-autocraft_6283624-p?searchTerm=battery+tools

Host pliers, reservoir, coolant temp sensor

To fix the coolant sensor:
Behind the engine block on the driver's side lives the sensor.  Pop off the connector to it that reads the temperature.  Use a 3/4 inch deep socket to remove sensor.  Quickly swap out the sensor with the new one including the ring provided with the coolant sensor.  Partially thread it with your fingers and then tighten it down with the 3/4 in socket.  Reconnect the sensor.  Done.

Coolant Temperature Sensor

To fix the coolant reservoir:
Remove the coolant from the reservoir using  a siphon or a fluid extractor like the one listed above.  If you don't care about the fluid you can allow it to run out but be sure to refill the tank to the fill line once this is completed.  I used this extractor and made the job cleaner, faster, and much easier.

The coolant reservoir is connected by 2 10 mm bolts.  Loosen the bolt on the front left side of the car and the one that is next to the fuse box.  After these were removed, disconnect the sensor from the bottom of the reservoir.  Then, use a mini crow bar (bout 10 inches long) or screw driver to pry up the fuse box corner and the reservoir's corner.  Remove the reservoir corner.  There is a hose on the top that connects to the reservoir and a large hose on the bottom.  Both of these are securely fastened with hose clamps.

Coolant Reservoir

These clamps can be nasty if you do not have the hose clamp pliers.  I first wrestled these with a pair of channel lock pliers.  I lost more than a few pieces of skin wrestling with these.  That's when I decided to get the above mentioned pliers.  These make the job 100x easier and can do it in 1/4 of the time.  Place the clamp pliers on the clamps and squeeze down on the handles to open the clamps.  The pliers will lock into position allowing you to let go of the pliers and continue working.  Once the clamps have opened, slide the clamps backwards with a heavy screw driver or the small crow bar.  Be careful to not damage or puncture the hose.

Bottom of Reservoir Hose Clamp 

The hose on the bottom is going to be the largest challenge as the hose clamp is located on the bottom facing the ground.  Extremely difficult to impossible with a pair of pliers (10/10 difficulty).  With the hose clamp pliers it made this a 2/10.  Once the clamp has been loosened, slide the clamp back from the reservoir to the point where the hose curves to give enough room for the hose to come off of the reservoir tank.  Now firmly twist, turn, force the reservoir off of the hose.  Use a screw driver, etc.

Slide the new reservoir into place and follow the steps backwards to complete the job.  With the correct tools and parts this took me about 30 minutes.  I also topped off the coolant was finished as I had lost a small amount from the fluid extractor.