SERVICE ENGINE light coming on

[Ducaire]

I've always heard not to worry when the service engine soon light comes on in Chevi's, because they're the doin'st trucks in the world about that. As long as I've had my S10, every now and then when I'd been driving for about 5 minutes, the SE light would come on, and after several minutes, go back off.
Well, about a week ago, it's started coming on like that every time I've driven, and just earlier today, it came on and stayed on! When I turn the key on, that light comes on instantly. I've still got a thousand miles or so to go before my next oil change, and I got my air filter changed about 3'500 (highway) miles ago; my oil pressure, engine temp. gauge and battery gauge look normal on the dash.

Could it be the transmission filter making it come on? I haven't changed it yet, and I've noticed when accelerating, my truck has this 'dirty' sound to it when the engine runs. It does not make this noise when it is in neutral, park, or on idol.

[jackass#1]

ses light is usually a emission fault. autozone will scan your computer for the fault code and let you know what it is for free.
any number of sensers (faulty) will make it sound and/or run like crap. when the ses light comes on there has been some sort of malfunction to trip it, then it leaves a code stored in the computer of that certain malfunction.

[Crasen]

What year S-10 is it? If it is a 96 or newer you need a scanner to get trouble codes. However if it is a 95 or older you can use a jumper wire on the diagnostic link connector and the check engine light will flash, you count the flashes and that will tell you the trouble code. You can also go to Auto Zone or Advance Auto Parts as already had been suggested

[MT-2500]

If it is your 90-S10
Jump A to B on your diagnoist connector and turn key on and count them flashes longs and shorts and post back what you get.
Or if you go to AZ here is some tips.
Use Caution when getting the free code checks please.
Some parts places do offer free code checks. And also free repair advice. But beware. Just get the code no and post it back here and someone will help you.
They offer the free code checks in the hope of increasing there parts sales.
Almost all of them will also offer mechanical advice and some know what they are doing.
But just remember most of them are parts people pulling codes for free.
Not trained professional tech/mechanics. Even if they pull a 02-sensor code or another sensor related code it does always mean to replace that sensor and your problem will be fixed.
Please just get the code no and post it back here and we will help you.
MT

[srbianats]

When was the last time you had the plugs, wires, cap and rotor replaced? When the SES light started comming on, did it ever start flashing quickly then go to a solid light? My guess would be a plug or wire going out. Especially noticeable when eccelerating. Just get the codes and come back here like the others have said.

[Ducaire]

Thanks for your replies.

No, the light doesn't flash when it comes on. This morning, it came on for about 3 seconds, and then went back off. It's never come on and went off that quick before. I'm no genius when it comes to automotive, so bear with me.

[MT-2500]

You need the code to know which direction to go.
And remember the code does not say replace the sensor it says check it out.
Go for the code check and post back code no.
And someone will help you.
MT

[RahX]

if it ONLY comes on and goes off after like 3ish seconds when you first start or turn the key on its the bulb check and is completely normal. but it sounds like somethin is actin up and then makes itself disappear. i hate those obdI systems sometimes >< the only way youre probably gonna get the code is if you have a scantool hooked up when it does it and youre recording a snapshot. but you might get lucky, go to autozone and get the guy to pull the code for ya. YOU CANT TURN THE KEY OFF, those systems when you turn the key off the code is lost. if autozone doesnt do it you might try an independent shop. it probably wont be free but at least if you get your girlfriend or another female to do it youll probably skate away without paying just send her up there alone and tell her to put on her best helpless puppy dog look anyway, all you want is the code and no bs so listen but dont. does that makes sense? anyway hit us back with the code.