I drive a 2007 Saturn ION with just under 84,000 miles. I was out and about last Friday and left the vehicle parked for about 1 and a half hours. Started up -no problems. Yet when I looked at the temp gauge I noticed that instead of reading cold the needle was on the first quarter mark. That has never happened before. OK so I drive it -the needle goes to the mid mark where it should be. I go somewhere else and park it for the same amount of time. Again I came out the same thing-needle at the quarter mark. So that evening after I let it sit for a while I went to check on it -turned the key there it was at the quarter mark. So I took a road trip and the vehicle ran smooth good pickup & no issues with the gauge. In fact I had gotten stuck in traffic for 15-20 minutes due to road repairs. The needle of course goes up a small bit but the fan came on and it went back to the middle. Is this a problem I should be concerned with ? The car runs well but I have issues with the power windows, the drivers seat headliner and outside trim. The typical stuff for a 15 year {built in late Oct 2006-sold in 2007} $15,000 GM sedan. It still has the original radiator hoses, serpentine belt. I have gone through 2 thermostats. The first replaced about 50,000 miles the mechanic (Triple AAA garage) that I had been going to 4-5 years for oil changes hosed me for $300! The gave me BS about having to reset the codes ! They lost my business and earned my ire. I have been going to a nearby Mavis location and so far so good. Guess what -the first replacement thermostat had to be replaced because it failed- something about the rubber gasket around the thermostat which I kept. It did need replacing because the gauge indicated a problem. You live & learn. I had the coolant changed ( used GM recommended anti-freeze) on 01/03/17 at 63197 and the second thermostat on 11/30/18 with 71,992 miles and the original thermostat replaced by the rip off Triple AAA garage on 03/22/14 at 49,269 miles . I did 22,723 miles between the 2 thermostats . Thank you and BTW I have had the usual Saturn ION repairs, stabilizer links and front wheel bearings also the struts. The ABS is shot and I am not going to fix that. The sensor is attached to a rear wheel bearing ( smart engineering-right?) and for what the age & vehicle is worth it doesn't pay . I have a transmission service question for which I enter another post. Thank you very much for taking the time to read my inquiry and look it over. BTW - as of late sometimes the key gets stuck in the ignition switch which is the replacement one through the recall notice. I doubt that this has anything to do with the problem but I thought you should know. If I play with it I can get it out and turn off the engine. There is no problem inserting it. Oil changes every 3500 miles last oil change on March 9 2020- I just reaching for have gone slightly passed the 3500 mile mark so I am going to change the oil very soon. No warnings have come on the dash for anything so far including the coolant warning light
I would not worry about that temperature gauge as long as the car drives fine and does not overheat. Odds are that the temperature sensor has some issues which I don't think it is a big deal.
Hi Yaser,
I appreciate your taking the time to answer. I checked on the part at an OEM site for GM and the part is not too expensive . The coolant temperature sensor is listed at $22.71 and the sending unit @ $19.71. I suppose that both are available as an after market part from another source. I know that you would of course have to actually see the vehicle but do you think that it is both or just 1? I figure that both go together.. I remember that on my last Saturn an SL level 2 sedan a sensor went and though I did not have an OEM part installed it was a lot more than these parts are listed for. I do not remember the type but it was inexpensive
It is most likely the sending unit only.
Temperature sending unit.
Hi Doc,
I appreciate both you and Yaser taking the time to answer my question. I have follow-up -how long can I drive with this situation? Thank you
It's probably OK to drive it. Over time, the sending unit brass body plug sometimes cruds up and corrodes and makes the gauge wacky. This would be my first choice as I have seen this many times. I have on several occasions just run the brass part of the unit on a wire wheel to clean it up and it worked just fine. Hardest part of the job was draining part of the coolant, refilling it and burping the system. The parts available from the local, discount parts places work just fine.