SL2 Won't Start - Common Issue? Help!

[JustinWB]

Not sure it's related but the car is idling a little high, the normal, then back to high etc... While in park.

I'm low on oil too.. gonna go get some now.


Justin

[fdryer]

Update your stats to reflect what you're driving, year and model. Without some car history about maintenance done, parts replaced, its all guessing.

Since you found a partially dead battery won't allow the starter to run and several starts finally got this engine to run, there are some questions to ask in addition to supplying more info. Saturns before '01 have the infamous faulty round nosed coolant sensor causing hard starting, flooding, rich running, overheating. Remove yours and see if its the round nosed one. If it is, replace it immediately with the flat nosed brass one. This will correct many starting and running problems.

The fluctuating idle may be the alternator charging the battery while supplying all the electricity for the car. Ignore it for now if nothing else is wrong.

[JustinWB]

It's a 98 SL2 with about 120,000 miles now. I just purchased it 4 months ago so a lot of the history is unknown to me. However, it was definitely kept in great shape.

What is the part that I need to replace?

[fdryer]

The engine coolant temperature sensor. See below. Its on the driver's side of the engine nearby but below and to the left of the egr valve, connected to a two wire connector.

[TomM96]

> The engine coolant temperature sensor.....
drivers side engine (EGR valve has heavier wires, looks like half a beer can)
The ECTS is small , almost hidden beneath the valve cover (below the overhang of the head), skinney wires.

[JustinWB]

Update:

Drove to work and back today after adding oil. Ran about 80 miles without issue.

I'm still uncomfortable that the issue is 100% fixed since I didn't really seem to fix anything. I am finding it hard to believe that my car stalled out and the key got stuck in the ignition due to a low battery.

I am going to change out the part suggested but does anyone have any seemingly final solution or explanation to this very strange issue?

[jasenpeters]

Originally Posted by JustinWB

It's a 98 SL2 with about 120,000 miles now. I just purchased it 4 months ago so a lot of the history is unknown to me. However, it was definitely kept in great shape.

Above may be a clue to your recent question...

Unfortunately a lot of things in life are rarely maintenance free for long periods.

4 months is plenty of time to "hide" some intermittent issues.
Weather, bumpy roads, style of driving, etc. can cause hidden problems to arise.

No history other than it's in great shape, whatever that means.

Key Sticking
-----------------------
I had my car for over 5 years with no problems with the key. Then it seemed to get stuck more frequently. Sometimes it was steering being locked. Sometimes it was the key getting worn. A combination of getting a new key every now and then, using some graphite on the lock, jiggling or articulating the key in different directions, turning it slow, etc, worked.

Short of replacing the ignition lock and key, I had to change my behaviour and be patient and keep trying and using what worked. I can't remember the last time I've had an issue with the key, or what I did, but I'm ready to try those things again when the time arises.

Starting & Stalling
-----------------------
This could be a combination of things that your car WILL experience from time to time, intermittently and unpredictably.

Cranking:
Battery, Starter and solenoid, alternator, loose connections....

Starting/Idle/Running/Accelerating/Stalling:
- Spark plugs, gaps and wires, Ignition Control Module, Crank Position Sensor, fuses, loose connections.....
- Bad gas, fuel line pressure, Fuel pump, fuel filter, pipeline clog, regulator, injectors, fuses, loose connections....
- Intake Air Temperature sensor, Engine Coolant Temperature sensor, Throttle body related sensors (MAP, IAC, etc.)...
- Compression leaks at Intake manifold, valves, head gasket, piston rings, etc.

etc. means I don't know for sure, but there could be and probably are more items to consider.

I think in your case, you coincidentally had different issues at the same time.
The only thing common that comes to mind is the recent change in weather.
Look at the recent forum posts, complaining of no starts, stalling and idle issues.
Even I had an issue a few weeks back (spark gaps were to large).
Never had this for a long time, but it happened.

Now, if you haven't yet heard about that little bugger, the ECTS, you can find plenty of "my car is possessed!!!" posts on this forum, where owners can't understand why suddenly their car has trouble starting, idle, acceleration, etc.
The pros here know the precise history and models that apply, but as I understand it the original design was a teflon "capsule" shaped cover over the sensor. The replacement and improved version is made of brass, which can withstand the heat and glycol exposure for much longer time. With a damaged ECTS, the PCM gets mixed signals and incorrectly adjusts the fuel air mixture, which will cause your car to sporadically misbehave.

I would replace it ASAP.

Other possibilities, may be, you need a "tune up".
Plugs, gaps, spark wires, filters, etc. things that need replacing on a regular "maintenance" basis.

Catastrophic things or things that tend to last for longer periods of time, from the mild, like fuses, battery, alternator; to the drastic, like head gasket, valves, timing chain, etc., still need to be considered, but the symptoms will likely indicate so.

Buying a used car is going to take learning curve patience and maintenance as the issues WILL continue to pop up as it gets older.

This forum will keep you running. Hang in there.