What's wrong with my car?

Question

Okay, so it's a 2000 Saturn L100. Recent oil change and air filter. Now it's all of the sudden starting to jolt when I'm at idle. At that point, it just between .5 RPM to .7RPM then down to .4 RPM then back to .5RPM. Driving steadily, or even accelerating, it's fine, no hesitation. Also, oil temp is normal, half a tank of gas (filled up Sunday), AC is fine. Please help, I'm begging!!!

Answer 1

If your engin light is on it could very well be the O2 sensor, sounds like you also need sparkplugs/tuneup, and sears has a three part fuel injection cleaner to. two out of three cars i've worked on that had that problem it was the spark plug, third was the fuel pump so you could probable get that checked out too. Air intake could be leaking, either from a damaged hose or lose or diconnected hose. All of these answers are pretty good answers.

Answer 2

Your problem is called "hunting idle". It can be caused by an intake vacuum leak as someone said, but I'm inclined to think your EGR valve (for your emission control system) or your throttle position sensor are at fault. These are the most common things we replace on the cars my shop works on. However, I have limited experience with Saturns. I would take your car to an experienced Saturn mechanic for a proper diagnosis.

Answer 3

Likely to have dirty fuel injectors. Two ways to go about fixing.
1. Go to the parts house and ask for an additive
2. Take it to the garage for a fuel injector clean up.

The first way is cheapest. I would try that first. Since the car only has problems at idle, the problem is not due to the high voltage ignition system (wires, plugs) because they fail under acceleration.

Good luck,

Answer 4

If it started after you got the gas on Sunday, then it may just be some bad gas. Put in a gas additive, found at any Wal-mart or automotove store. Next time fill up with a bit of premium.

Good luck!

Answer 5

I like the details in your question.

One of two things:

1) Stuck E.G.R. valve. (that's a shop repair)

2) vacume leak at the intake manifold. (you could do this)
Listen for a sucking sound with the engine running. You may have to feel around the back side of the intake manifold to locate a hose that may have come off.

It could be something else, but those are the most common.

Answer 6

treat cheap first; possible fuel or air filter change. injector cleaner. bad gas; high content rubbing alcohol (75%) put in tank plus prem fuel. plus injector cleaner. Then, try to use same gas from same station from reputable dealer. Discounts are not good when it comes to performance. I know. Finally, have it checked.

Answer 7

possibly the IAC (Idle air control) motor. Don't attempt this yourself. Some cars require certain preparations before installing a new one. Take the car in

Answer 8

i am no expert, but you could have the timing checked, and the idle guage checked. also, there could be water in the gas or just moisture. there is a bottle of gas treatment you can buy at any local auto parts store, even walmart, if you think it could be the gas. it happens, especially in poor gas stations that need to have their tanks cleaned or repaired.
best bet though, is to take it to a qualified mechanic.

Answer 9

You neglected to mention how many miles are on her. Try running a can of fuel injector cleaner next time you fill up!

Answer 10

Sounds like bad spark plugs or wires. If you don't know how to check them, ask a guy friend of yours to do it. If the spark plugs are fine, the IAC might be dirty.