having auto probs, your opinions please.

[redbone]

auto: 1996 saturn sl2 1.9l.
probs: over the last few weeks when i start the car in the morn it sputters and idles hard. spits black smoke. then it will idle normally [if it starts] and will be fine as long as it is warm.
i figured possibly bad plug wire(s). remove plug wires and sure enough find a broken one. i figure problem solved.
car sits for a day unused.
go to use it for work mon morn and the same old prob exists, but i get it going and take it to work only to have the same prob at end of the day.
get the car home, remove sparks plugs. they look good (they were actually replaced in june) with the exception of one cylinder. the electrode part of the plug (where it sparks) was o.k. but the rest of the threads were covered in oil.
as best as i can see into the cylinder, it looks like there is oil laying on top of the piston.
again, as long as the car is warm there is no prob, when cold there is a prob.
so...what do you all think??
redbone

[XS1100 Newbie]

Being fuel injected, i would look at the cold start valve, or whatever the Saturn uses for it's cold start feature. It works as a choke sort of.

[TopCatGr58]

Hmmmm,

Oil on the plug end and piston, sounds like you might have a leaky valve seal, engine compression, heat, etc., doesn't allow much to leak down into the cylinder once it's running...probably an exhaust valve....hard to start due to excessive oil in cylinder. Once you turn off the engine, oil in head drips down around valve past seal and into cylinder.

Or could be a head gasket weakening, and you're getting some oil leakage from the oil channels getting into the cylinder.

You could try some of that engine seal conditioner additive to see if it might help the valve seal, easy and not too expensive to try before possibly tearing into the engine!? JAT!

T.C.

[BA80]

auto: 1996 saturn sl2 1.9l.
probs: over the last few weeks when i start the car in the morn it sputters and idles hard. spits black smoke. then it will idle normally [if it starts] and will be fine as long as it is warm.
i figured possibly bad plug wire(s). remove plug wires and sure enough find a broken one. i figure problem solved.
car sits for a day unused.
go to use it for work mon morn and the same old prob exists, but i get it going and take it to work only to have the same prob at end of the day.
get the car home, remove sparks plugs. they look good (they were actually replaced in june) with the exception of one cylinder. the electrode part of the plug (where it sparks) was o.k. but the rest of the threads were covered in oil.
as best as i can see into the cylinder, it looks like there is oil laying on top of the piston.
again, as long as the car is warm there is no prob, when cold there is a prob.
so...what do you all think??
redbone

There will be a intake air temperature sensor either in the air intake hose or in the manifold. Also a coolant temperature sensor in the engine itself. These tell the PCM the engine temp and intake air temp, obviously, so it knows how much fuel to feed the engine according to running conditions. A colder engine will need more fuel and if the sensor is reading inaccuatly it might be thinking it's at operating temp when it's actually cold.

The only way to actually tell is with a scan tool.

Is the check engine light on?

[DGXSER]

Just asking, but are you sure its oil and not excess fuel? The runnign like crap cold and then not when warm would tend to say it is fuel / enrichment / choke related. It would be very unusual for only one cylinder to have that bad fo valve seals and the others show no sign of it. Could also be a weak coil, do not know the saturns that well, but do they have individual coils for each cylinder?

[bikerphil]

If you go to Autozone, they'll hook up the code scanner for free and diagnose.

[BA80]

Just asking, but are you sure its oil and not excess fuel?

when i start the car in the morn it sputters and idles hard. spits black smoke. then it will idle normally [if it starts] and will be fine as long as it is warm.

The black smoke indicates too much fuel. That means I was probably backards on my guess too. I have run into a few that the temp sensor, either coolant or intake air, showed -50º and was dumping the fuel to the engine.

I've seen a bad O2 sensor do the same thing.

One way to tell is unplug the sensor and that will force the PCM into limp home mode and default to a preset median parameter. In other words, if that component is causing the problem it will smooth out.

As I said, the only good way to tell is with a scan tool.

[Brent]

sparkplug

If I had run for a while with a broken plug wire, then found that the plug there was dirty or fouled, I would clean or replace it. Broken plug wire could lead to dirty plug. plugs are cheap enough, or cleaning & regapping may due it to.

Free code reader may tell you MORE

Good luck wrenching

[redbone]

thanks all, here's an update.
some folks from the saturn forum gave me the heads up and a couple of you guys were on the rite track.

evidently the coolant temp sense is most likely the prob. it thinks the engine is warm all the time.
the other prob is most likely just the valve cover gasket. oil is leaking into the spark plug cavity (they're those real deep ones) and when i pulled that plug, all the oil that was laying in the cavity poured onto the plug threads and rite into the cylinder. i had forgotten that the oil was on the socket as well.
now all i need is a saturday to fix it.
thanks to all.

[Jerry]

Have been a past member on the Saturn forum, some good info there. I had a similar problem on my '91, was also the coolant sensor. Not a hard fix, but seem to recall there were 2 versions or sensor, and you want to get the later one. (Probably all the early ones are gone by now, its been a few years!)
You neeed a deep dish socket (14mm?) and don't have to drain the coolant to change, but it will leak a small bit when you remove the old unit.

[cywelchjr]

If you go to Autozone, they'll hook up the code scanner for free and diagnose.

Depends on where you are. Here in Ca they have made it against the law for them to do that because the repair shops all complained that it was taking away their business.

[redbone]

update to all:
the guys on the saturn forum were dead on. it was the coolant temp sensor.
changed that, and no more probs. amazing how that little sensor can cause headaches.
thnaks again to all who responded,
redbone