Uh Oh Trouble

96 sl2 lately it has been lagging alot, it won't accelerate like it used to. Usually not tell I am around 3500 rpm, and the a.c. has also seemed to get hotter, it doesnt stay as cool, and when it does cool it doesn't stay cool unless youa re at 3000 rpm.

any one know

it can be a few things

basic checks: air filter, coolant, belt, spark plugs, throttle body(carbon buildup), fuel pressure, electric fan(should turn on with A/C on), radiator/condensor and intake for restrictions

is the lag only when the A/C is on?

one possible theory: the ECT (Engine coolant temp sensor) is a known trubblesome part for the S-series, when it fails, typicily the SES light will not set, and the computer will beleave the engine is colder then it actually is, then computer will then enrichen the fuel mixture to help get it up to temp(dispite the fact the engine may already be at temp). this can in fact cause the engine to overheat, but the computer wont know it.(its a little bit like a thermostat stuck open). running overly rich will cause a loss of power as well as hurt fuel economny. then with the engine overheating, in turn the trickle effect will increase radiator temp, then increasing condensor temp, which increase the A/C high side pressure, possiblely to the point the pressure cut-off switch is set. this is more likey if the system is overcharged.

but thats assuming the two problems are related. does this theory sound possible to you?

it can be a few things

basic checks: air filter, coolant, belt, spark plugs, throttle body(carbon buildup), fuel pressure, electric fan(should turn on with A/C on), radiator/condensor and intake for restrictions

is the lag only when the A/C is on?

one possible theory: the ECT (Engine coolant temp sensor) is a known trubblesome part for the S-series, when it fails, typicily the SES light will not set, and the computer will beleave the engine is colder then it actually is, then computer will then enrichen the fuel mixture to help get it up to temp(dispite the fact the engine may already be at temp). this can in fact cause the engine to overheat, but the computer wont know it.(its a little bit like a thermostat stuck open). running overly rich will cause a loss of power as well as hurt fuel economny. then with the engine overheating, in turn the trickle effect will increase radiator temp, then increasing condensor temp, which increase the A/C high side pressure, possiblely to the point the pressure cut-off switch is set. this is more likey if the system is overcharged.

Yes the lag is all the time, and is the ECT something that I can change, or does it have to be changed somewhere. I have all the basic mechanic skills, anything on caarburator I can do but the new stuff is tricky. Let me know.

but thats assuming the two problems are related. does this theory sound possible to you?



Yes the lag is all the time, and is the ECT something that I can change, or does it have to be changed somewhere. I have all the basic mechanic skills, anything on caarburator I can do but the new stuff is tricky. Let me know.

i'm not a big fan of throwing parts at a problem, but like i said it is a known problem and is easier to replace then test. the sensor itself cost no more then $20 at a dealership, and in the chance the connectior is also bad(visual check) its only a little more.

http://www.saturnfans.com/forums/showthread.php?t=24003
http://www.saturnfans.com/forums/showthread.php?t=37884

could this maybe be a problem with the fuel filter also. JW

its possible, have you changed it in the last 2years/30,000miles?

its possible, have you changed it in the last 2years/30,000miles?


Well my fiance bought it in August has put about 10000 on it so I have know idea. I got under there and it looks as if it is a saturn filter. So maybe I will also try that, I went and got the ects and it was 9 bucks so I will put that on and see if it works if not then I will try the fuel filter. Could it be anything else?

did you run thru the basic checks i listed? that covers all of the common problems i can think of.