Engine light...wierd

[TdotAlero]

Hey, I have recently fixed (almost) everything in my Alero. Out of 5 warning lights on the dash, I had only the service engine light. Anyway somewhere, someone told me it was the gas cap that was causing the light to go on. Anyway so I picked up a gas cap from a junk yard (what looked like a better condition cap than mine at least) and replaced it. The light was still on so I though eff it, I don't have time now. About 4 days ago my battery has died overnight and after boosting the car the engine light was gone. I though whatever it will be back in 5 minutes like always when battery dies. It didn't come back on. I drove to work and back (80kms). Next day same story, no light. After work though I start the can and the light is back on.... afte a day and a half and making 150kms, the light comes back on. I checked the gas cap and figured that was not the problem. I guess it couldn't be faulty sensors cause the light wouldn't take so long to come back on.... I'm out of ideas.. what can cause it to come back on after such long time ? Thanks..

[Redog]

Gotta get it scaned.

If they scaned it and it was the gas cap, it's code P0442

[Nate's Alero]

and the code is?

[TdotAlero]

Gotta get it scaned.

If they scaned it and it was the gas cap, it's code P0442
Tbh I don't remember the code name. I work in a car shop but we don't have a computer to scan cars. I will (hopefully) go to neighbours tomorrow and check it out. What got me thinking is why would it come back after driving for 150kms..

[Nate's Alero]

Tbh I don't remember the code name. I work in a car shop but we don't have a computer to scan cars. I will (hopefully) go to neighbours tomorrow and check it out. What got me thinking is why would it come back after driving for 150kms..

EVAP, BBEVAP, something stupid and useless

[TdotAlero]

EVAP, BBEVAP, something stupid and useless
I think more likely evap. I wouldn't care much about it, but I am planning to sell the car in spring next year, and customers liek to nag about warning lights :p

[Nate's Alero]

why does everyone want to sell their alero's !?

[TdotAlero]

why does everyone want to sell their alero's !?
The reason I "want" to sell the Alero is I want to upgrade to a coupe with manual transmission and lower mileage.

[Nate's Alero]

The reason I "want" to sell the Alero is I want to upgrade to a coupe with manual transmission and lower mileage.

another alero?

good man. :p

[smokey]

why does everyone want to sell their alero's !?

because the V6s are nothing but trouble, i wish i had the manual coupe

[Vella's Alero]

when the light was going off and on did you fill the has tank between that?

[JLw7123]

because the V6s are nothing but trouble, i wish i had the manual coupe
yes the 3400s have a lot of problems but when u fix them the engine is fine.

[TdotAlero]

when the light was going off and on did you fill the has tank between that?
I have, using the same grade gasoline, however I filled it up about 50kms before the light went on.

And the V6 motors are good motors as long as you do basic maintenance.. :rolleyes2:

[Vella's Alero]

If it was 50km before the light went on then this might not apply but I have the same light on and when I got my mechanic to replace my head gaskets I asked him about it and he asked me if I changed teh gas cap and I told him that I did.

I asked what it could be and he told me that it is one of the most useless codes because it is not specific enough. It could be the gas cap, the fuel sensor, the pump that pressurises the fuel tank, or a sensor in the engine bay.

Apparently, after the fuel sensor detects that a certain amount of gas is out of the tank it starts to pressurize the tank so the fuel won't evaporate. The sensor measures the pressure by a bladder that expands and contracts and if it starts to crack because it gets old then it can't read the bladder correctly and turns the light on because it doesn;t think the tank is pressurized.

Now if it is not that it could just be a sensor in the engine bay just not reading what the sensor's is sending, a wire that connects the systems that is faulty, the pressurization pump for the fuel tank, the pressure bladder, the sensor in there, or about another 2 or 3 things that I can't remember he told me about.

That is what I remember from 2 months ago. If you want more info I can talk to him again and see what he says. Basically that is the only light on on my dash as well and I just decided to live with it.

If you can make heads or tails of that...props to you...lol:haha: