1998 Saturn SL2 Question for serious answerers only?

Question

I have a 1998 Saturn SL2. It starts up normal, sounds normal, no noise at all while in idle or while driving on road. Problem is that when I stop at a stop sign, or slow down to turn somewhere (store, or whatever) my RPM's drop to below 100. It usually sits just slightly above 100 in idle. I've already replaced the battery, just had the oil changed last week, checked spark plugs, wiring, etc. But for some reason, it continues to do this. It's at the point that I hate knowing I have to drive it to work (25 minutes away) in case in breaks down and I'm stuck at work.

Could it be as simple as a dirty fuel injector filter? Or is it my battery (which is only 6 months old and top of the line)? Again, there's no noise, car doesn't sound like it's laboring, just the RPMs drop way too low, almost to the point of conking out. More frustrating than anything and causing me concern since I need this car, especially as a single-mom with 2 kids.

Serious answers only please!!

More info: Not a bad guage, and yes my car idles at 100 rpms. I've owned it for 5 years now, therefore I think I know what is "normal" for my car and what isn't. I'm not here looking for people to tell me what I do not know, but what I can do to narrow down the problems so I can have it fixed. I would like to go into the garage with some sort of knowledge so I don't get screwed out of money which I've been paying out for nothing to the garages thus far.

Please again, do not tell me I don't know my vehicle. Same with anyone else who's owned their car or truck, you know when something is wrong and when it isn't. I may not be a mechanic, but I'm not completely stupid either.

Thanks to those who answer with some sort of knowledge rather than bad mouthing me about my car due to the fact that I'm female.

Answer 1

i own a repair shop,and it sounds like it may have a dirty gas filter on it,and also a air filter will cause one to loose rpm,s like that ,if you have noticed any hesitation in it ,,id have the fuel filter replaced on it,that's a cheap price to pay to get it repaired if it still does it after the filter is put on it,you may have to have it checked out,but i think a new filter should help it a lot,,good luck,i hope his help,s.

Answer 2

Is this a new car for you? How long has this problem been going on? Saturn's of that era have what was called back then a "fuzzy logic" computer controlling the engine and transmission and idle. That computer attempts to anticpate braking and accelerating habits of the driver for smoother shifting and better fuel economy. Because of the nature of the computer's control of the idle it will fluctuate up and down based on its analysis when you are braking, if you are coming to a complete stop or just slowing down before you press the accelerator again. It also adjust the idle or is supposed to when the air conditioner compressor kicks on which would other wise pull the idle down.

It is more likely that your generator or the part of it that regulates flow of electricity to the engine is going bad. This happened on my Saturn and produce idle fluctuation as well. You said that you checked your sparkplug wires so I did not mention it but on my Saturn two of my sparkplug wires had deteriorated around 110, 000 miles and so that at less speeds not enough electricity was being pushed through to actually power all of the cylinders properly at lower rpms until one day I stalled out completely. When the wires were replaced the problem went away.

A fuel injector, possible but it would have symptoms of an interrupt or "stutter" on acceleration from a stop, but it could be. If your car starts, your battery is most likely fine. If you start your saturn, turn on the lights, and then remove the terminals from your battery you can get and idea if your generator is failing. If the car dies when the battery terminals are removed the generator is the culprit, if the car idle changes or the lights become noticeably dimmer the generator is weak and may need to be replaced.

Answer 3

There's no such thing as a car that idles at 100rpm. If it's idling smooth and you're just looking at the gauge, it's a bad gauge. Don't fix it if it ain't broke. Get cheap device that measures rpm by hooking around a spark plug wire.

Answer 4

well defenatly not your battery or your oil but it could be a number of diferent items such ascold start injector, idle air control map or baro or mass air flow sensor orr just a 02 sensor may be the culprit ... best thing to do is have some one check the computerfor certain problem codes ..

Answer 5

if your battery was going dead the car would not run at all,it could be something as simple as the tach not reading right,next time it does this stop by a shop and have them hook up a scan tool to check the rpm,it will be cheaper that continuing to buy batteries.

Answer 6

I had the same problem with my car, but it was to the point it shut off when i came to a stop. It was my idle air control sensor.

Answer 7

unless you are a mechanic, give it up! it still could be a hundred things...
take it to a pro or play the parts changing game. sounds like you already wasted a bunch to no avail...now let a pro fix it or carry some walking shoes with you.