Cooling System Problem?

[kyasarin]

I have a 1998 SL2. About 2 or 3 months ago, my service engine soon light came on and when I had it checked I was told that I probably had a bad sensor on the engine temperature. I can't remember what the technical name for it is. It will cost me about $100 that I don't have right now to have it fixed. Since I have owned the car, for about a year now I have always had to keep a check on the oil level and top it off about every week or so, but I heard that this is common for saturns to burn through oil. Well, the engine temperature gage on the dash inside of the car is reading normal and I don't know if this data comes from that sensor that is bad or if that is something seperate. Tonight, my car stalled out on me. I cranked it back up fine and didn't have any problems on the way home, but I noticed that the rpm gauge needle jumped a few times, which worries me. There is something going on with the engine and I think that it may be running too hot because when I checked the oil level, it was down again and I just filled it up a week ago. I mean it was almost all the way down on the oil stick. It is not leaking oil. I changed the oil 3 months ago and the oil is black now. Also, the ambient temperature around the engine felt much hotter than usual, and I also smelled a bit of a burnt smell. I need help. I have not checked the engine coolant level yet, because the engine was still too hot, so I will do that in the morning. Is is possible for me to replace that bad sensor myself?

[adventureoflink]

Dude, first off, you can save yourself ~90% of what the garage wants to replace your ECTS (which is the name of that sensor, btw) by doing it yourself. It's REDICULOUSLY easy to replace, read the how-to section for more information. Replacing that ECTS can help resolve your stalling/flooding issues. and BTW, the ECTS is around $10 or so at Auto Zone, get the BRASS TIPPED variety. While you're in there, check your ECTS connector for corrosion, bad splicing, and a bad connector in general, it can also affect your vehicle's proper operation, even with a brand spanking new sensor.

Next, your RPM gauge jumping around is probably your IAC valve. Replace or clean it.

Also, yes, that sensor on your engine (ECTS) does control your temp gauge readings. A bad ECTS will cause these wonky readings and lots of other oddities.

[kyasarin]

I just watched richpin's youtube video on how to replace that sensor and now I am outraged at how much they were going to charge me! You are right, that looks very easy to do. The temp gauge is reading normal, just a little over the 2nd line. Could it still be a bad sensor? I forgot to mention that the red light that appears to be a cooling tank level warning light keeps blinking. I checked the coolant level back when it first started happening at the level was fine. I will check it again in the morning just to be sure. Any idea why the oil looks burnt up after only 3 months? Also, I have been getting pretty crappy fuel mileage lately. Could these be connected?

[adventureoflink]

Originally Posted by kyasarin

I just watched richpin's youtube video on how to replace that sensor and now I am outraged at how much they were going to charge me! You are right, that looks very easy to do.

Yes, you should be outraged. $10 sensor + $10 for a gallon of coolant (in the event that you'll need new coolant, when I did mine I accidentally forgot to take off the reservior cap, and all my coolant escaped. whoops lol) + ~$80/hr for labor, when give or take it'll take 30 mins, TOPS.

Originally Posted by kyasarin

The temp gauge is reading normal, just a little over the 2nd line. Could it still be a bad sensor?

Yes, still could be a bad sensor. Also, what do you mean the 2nd line? If you're talking about the 1/4 line (line above the C line), that's abnormal. Your car should be operating at ~195 degrees F (or about the 3/8th line.)

Originally Posted by kyasarin

I forgot to mention that the red light that appears to be a cooling tank level warning light keeps blinking. I checked the coolant level back when it first started happening at the level was fine. I will check it again in the morning just to be sure.

Stuck float/sensor. You can either flush your cooling system yourself (either using a garden hose or 3 gallons of distilled water+1 tablespoon of electrosol, run a gallon of distilled water and electrosol, run for 10 minutes, drain, lather rinse repeat, without electrosol the 2nd and 3rd times), and/or whack your reservior with a ratchet or something.

Barring that, water pump/radiator replacements may be in order for your car, they tend to go out after 10-12 years.

Originally Posted by kyasarin

Any idea why the oil looks burnt up after only 3 months?

No idea so far. Someone else can chime in on this.

Originally Posted by kyasarin

Also, I have been getting pretty crappy fuel mileage lately. Could these be connected?

the fouled ECTS can cause bad fuel economy, yes.

[kyasarin]

So the temperature gauge needle should be at the 1/2 line?

[kyasarin]

In this video, he says that it should be somewhere between the 2nd and 3rd line.

Skip to about 2m13sec in the video.

http://www.youtube.com/watch?v=YS8zGRfMzqs

[BarnOwl]

The sensor is a known weak point on these cars. I really don't care what your temp gauge is reading. If you have the old sensor, your car needs repair in my book.

Normal temp reading for that year is a little over 1/4. That's no reason to assume you don't need a new sensor.

[surprisinguy]

Originally Posted by kyasarin

somewhere between the 2nd and 3rd line.

He's right. Change the ECTS 1st and foremost. Check to see if you need a thermostat afterwards. You can do that by starting a cold engine and grasping the top right radiator hose. If it heats up as the car warms up your thermostat is bad. You can change that too yourself. More than likely the ECTS swap will fix most problems you're having.