Question about my saturn not shifting

scolls · 06-13-2007, 03:46 AM

My saturn is a 94 SC2, with the 1.9L twin cam engine and an automatic transmission. when the engine is cold, it shifts into 4th gear but runs at a higher rpm then when it's warmed up. at about 55 mph when it's cold my rpm's are at around 2600 vs. about 2300 when it's warm. it shifts smoothly, and when i manually shift it from 4th to 3rd, it does downshift. my question is, is the car not shifting into overdrive when it's cold, or does this car just run at higher rpm's when the engine is cold? is this something that is common with these cars? the car does have 146,000 miles and i checked the trans fluid and it is full and does look or smell burnt.

**Ssicarman** · 06-13-2007, 04:21 AM

Check your PCM coolant temp sensor. The trans torque converter will not engage until the engine reaches a certain temp. If the sensor is skewed and sending the wrong temp reading the converter lock up may be getting delayed.

scolls · 06-13-2007, 04:43 AM

Quote:

Originally Posted by Ssicarman

Check your PCM coolant temp sensor. The trans torque converter will not engage until the engine reaches a certain temp. If the sensor is skewed and sending the wrong temp reading the converter lock up may be getting delayed.

i'm not mechanically inclined per say, but how would i go about checking it, and where is it located?

scolls · 06-13-2007, 04:59 AM

is this the part you are reffering to? http://autozone.com/R,APP222734/vehi...ductDetail.htm if so for that price i would just replace it.

**Ssicarman** · 06-13-2007, 05:10 AM

It is on the back lower middle of the cylinder head. It has a two wire connector going to it.

scolls · 06-13-2007, 10:01 PM

i have been searching this forum and noticed this sensor seems to be a common problem, so for $11 i'll just replace it. also from my searching i noticed when it's warm outside and the car has been sitting, it is hard to start and it seems this sensor was recommended as a solution. also after looking underneath, i checked my oil and i'm half a quart low after about 1200 miles. i noticed some fresh oil on top of the engine so i think the valve cover gasket is leaking, so i'll probably replace that, and put on some new plugs and wires while i'm at it. anybody got recommendation for good spark plugs to use?

scolls · 06-15-2007, 12:12 AM

i also notice this car runs pretty warm at high speeds. the fan is working, the coolant looks good, no leaks, so could this also fix my overheating problem? the car runs past halfway at 70 mph, and it cools back down at 55. this weekend i plan to replace the ects so hopefully that cures everything.

PurdueGuy · 06-15-2007, 02:57 AM

yes, you may see a difference in how your temp gauge reads with a new ECTS, since it is what sends the signal to the PCM and the temp gauge on your dash.

brad_bb · 06-15-2007, 09:42 PM

Saturn engines are notorious for losing oil. Personally from my observations I think a lot of the loss is through the PCV which runs into the intake. There's also been some consensus that burnt oil from the PVC gums up the piston rings (mine were at 130K miles) which allows further oil burning (oil control ring not working properly).
Yes that temp sensor is a cheap one to replace. the replacement should be all brass. The plastic ones were prone to failure. Dealer only sells the brass ones now. On my car I also had a problem with the connector wires to that sensor. The dealer sells a repair kit for that connector which consistes of the connector and the two wires which you cut off the old connector and splice to the remaining wires.

scolls · 06-15-2007, 10:51 PM

well started the engine up, removed the oil cap and there is a lot of air pressure coming out which iirc indicates blow by. it also has some bluish/white puffs of smoke on start up. i did replace the pcv valve, but the valve cover gasket is leaking so that is part of my oil lossage.