Another cooling problem

[newmanw10]

So I know this has been discussed before but I cannot seem to figure out what is wrong.

I own a 97 SC2 and about a year ago I notice a drop in gas mileage. At the same time I noticed my temp gauge was at 1/4 all the time, when it used to stay at 1/2.

I thought my thermostat might be stuck open so I decided to change it. After changing it the temp was still slways at 1/4.

After that I also noticed that when idling the temp would go above 1/2 before the fan came on. The fan did come on so the car did not overheat but I have never seen my temp go above 1/2 before.

Yesterday I read some posts about the temp sensor (ETCS) and it sounded like that would solve my problem.

I changed it today and the temp was still to low, but it did move over 1/4 "a little". It still goes to 1/2 and above after idling fo a while. But this is only during idle, once I start moving again the temp drops back to around 1/4.

My gauge was always at 1/2 before, what happened? Why is it running to cool, and at idle what seems to be to hot?

Please help!

[Cat Fuzz]

Check the ECTS connector for green gunk disease. If it looks corroded, replace it with a new one from the dealer.

[newmanw10]

Sorry forgot to mention, ETCS connector looks brand new, no green gunk or signs of corrosion. Although i may replace it anyway as a last resort.

I wonder if the problem is with my coolant. I did lose a little in the etcs replacement and added in water and the temp changed a little? just a thought, i know i am probably reaching.

[Cat Fuzz]

The new thermostat could be stuck open. I've had defective thermostats right out of the box before.

[drew300]

With my '99 SW1, the temp guage has always been just over 1/4 when fully warmed. It's been though 3 (?) emission checks, and passes by a huge margin, so I don't think it's defective. The car gives very good mileage also. (if driven VERY CAREFULLY, I can just break 50 mpg.
Also, I check any new thermostat against know good ones, and with a cooking thermometer. I've had new bad ones also.

[newmanw10]

I am wondering if I should replace the connector to the temp sensor. I don't see any corrosion, but I guess you never know. Anyone know of a good way to clean the connector, I could try that before replacing it. Also if I do replace it whats the best way to seal the spliced wire connection, I know that electrical tape sucks.

I also noticed that when I replaced the temp sensor the coolant was green (previous owner). I bought some flush and the correct antifreeze at autozone (dex-cool) and flushed the fluid. I was hoping that would fix things but no luck. At least its running with the correct coolant.

Also could it be my coolant cap. I.E. maybe its leaking and not providing the PSI it should. Anyone else changed the cap with any luck?

[Cat Fuzz]

IMO the green coolant is better. The Dex-cool stuff can cause major problems if not used properly.

[newmanw10]

I am confused

I thought that GM cars should only use dex-cool. The manual and several posts have suggested problems with using other coolants with GM aluminum radiator.

I have seen several posts suggesting that using anything other than dex-cool could cause a build-up in the radiator.

Oh well either coolant did not change my car condition.

I appreciate your help and replies thus far!!!!!

[sierrap615]

a bad cap is possible, also keep in mind it is winter, ambient temps will cause you engine to run colder.

about coolant. by itself, regular old coolant will eat away at aluminum, 30 years ago no problem, almost everything was iron or steel. now for several reasons(mostly light wieght) more parts are moving to aluminum(both the engine and radiator for saturns). additives are added to coolant to reduce the corrision, you must make sure whatever coolant you use meets all of GM requirements for anticorrision additives, which should be cleary listed on the bottle.most coolants do have the additives needed these days, and Dexcool has been anticorrision since day one. dexcool was introduced in 96 and was used on all GM cars by the end of 97. Dexcool in GM's trademark for their own extended life coolant, which most manifactiors have their own verison. for GM cars that use Dexcool the radiator cap is pink or red(unless the cap has been changed of course) some cars can interchange green and extended life coolant with a flush. if you are not sure what type of coolant to use. check out Peak's Global Anti-freeze, its an extened life coolant thats designed to be compatible with every make and model, no matter what the orginal coolant was.

[newmanw10]

Thanks for the coolant info!

I am still frustrated with the cooling system and here is why.

I have read a lot of posts by a lot of saturn owners saying that saturns should run between 1/4 and 3/4 especially the S series. This is not true! I have owned my saturn for over 5 years and up until about a month ago my temp was always at 1/2 NO MATTER WHAT! Winter/Summer, idling/driving 80 on highway once the car warmed up with a few minutes of driving the temp gauge would sit at 1/2.

All car engines have a normal operating temp. This is the temp in which the car is supposed to run. I have never owned a car other than my saturn that has not run at the mid way point on gauge. Yes I realize its just a gauge, but when my gauge says 1/4 and my mpg dropped from 36 to 25 I know that there is something wrong.

I have changed the thermostat (twice) thats not the problem. I have also changed the temp sensor. The connector looks brand new. Coolant has been flushed and changed.

Hopefully someone has had this problem before an actually fixed it such that the gauge once again always reads 1/2. Although it seems that most saturn owners just make up the excuse that the gauge at 1/4 is ok. That is wrong ask the dealer it should run at 1/2, mine did for 5 years 1/4 is not normal!

Anyone else have any ideas?

Thanks!

[drew300]

Well, when I road-tested my Saturn SW1 before buying it, as it was warming up, I asked where the needle sits. The sales rep sad they sit aound the 1/4 mark. It's been there ever since, except it does climb when I get stuck in parked traffic, and I think at just above 1/2, the cooling fan kicks in. At least 3 other vehicles I've had, "normal" was less than 1/2. And some had numbers on them, and corresponded with the thermostat pretty well.
My car has passed about 3 emission tests with flying colors, and gives very good mileage, and runs well. Maybe my guage is out, but I think "if it ain't broke, don't fix it" applies here. At least it tells when it's cold, warm, normal, hot and getting hotter.

[4minc]

Originally Posted by newmanw10

Thanks for the coolant info!

I am still frustrated with the cooling system and here is why.

I have read a lot of posts by a lot of saturn owners saying that saturns should run between 1/4 and 3/4 especially the S series. This is not true! I have owned my saturn for over 5 years and up until about a month ago my temp was always at 1/2 NO MATTER WHAT! Winter/Summer, idling/driving 80 on highway once the car warmed up with a few minutes of driving the temp gauge would sit at 1/2.

All car engines have a normal operating temp. This is the temp in which the car is supposed to run. I have never owned a car other than my saturn that has not run at the mid way point on gauge. Yes I realize its just a gauge, but when my gauge says 1/4 and my mpg dropped from 36 to 25 I know that there is something wrong.

I have changed the thermostat (twice) thats not the problem. I have also changed the temp sensor. The connector looks brand new. Coolant has been flushed and changed.

Hopefully someone has had this problem before an actually fixed it such that the gauge once again always reads 1/2. Although it seems that most saturn owners just make up the excuse that the gauge at 1/4 is ok. That is wrong ask the dealer it should run at 1/2, mine did for 5 years 1/4 is not normal!

Anyone else have any ideas?

Thanks!

Mine is doing the same thing. Drop in mpg. Use to get 30'ish but now am around 25. However, my coolant light flashes every so often. I have already replaced the temp sensor in the engine. temperature is more consistant, but light still flashes. When it warms up some outside I am going to pop off the coolant tank and see if there is any sensor in there.

[hueroloco]

my saturn ran at half all the time once it warmed up after I changed the sensor and the connector. I replaced the thermostat and flushed the coolant at the same time and i put in green coolant. It was all good after that.

GM has an ongoing class action lawsuit for their DEXCOOL crap. Anytime a car comes to our shop with that stuff I recommend flushing it out! I just read a great article in a magazine called "Cool Profits" about the sludge build up and gasket wrecking that DEXCOOL stuff causes.

[RC1488]

CLARIFICATION:

'91-'95 S-series cars have an operating temperature reading of 1/2 on the guage. About 1-2mm before the needle hits the red zone the fan will turn on. THIS IS NORMAL

'96 - '02 S-series cars have an operating temperature reading of 1-2mm above 1/4 on the guage. When the needle reaches 3/4 on the guage, the fan will turn on. THIS IS NORMAL. Anything different from this is wrong.

OP: Your car was running hot for the last 5 years. It is now running up its correct temperature.

[RC1488]

Originally Posted by 4minc

Mine is doing the same thing. Drop in mpg. Use to get 30'ish but now am around 25. However, my coolant light flashes every so often. I have already replaced the temp sensor in the engine. temperature is more consistant, but light still flashes. When it warms up some outside I am going to pop off the coolant tank and see if there is any sensor in there.

Clean your resiviour tank. The sensor is very sensitive and sometimes dirt can get into it. Its a float sensor that is part of the resiviour. The entire thing needs to be replaced if the sensor is bad, however a good cleaning should be all that is needed