Since Sept, my check engine light has come on a total of 6 times. Every time, I bring it into the dealership to get it fixed. The first time, they told me it was a loose gas cap. The next couple times they said that different codes were coming up, and they continually fix something (they’ve changed the sensor in the gas tank, changed the filter in the front and the back of the car), but nothing seems to do the trick. This last time, I got the car back right before Halloween, and the light came on on Thanksgiving. Any ideas to what the problem could be?
That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.
It sounds as if the dealer itself may be the real problem.
What are these front and rear filters that got replaced? Fuel filters?
Is your car out of warranty?
Have you been paying for any of these repairs?
What codes are you getting?
It sounds like you might have an evap problem.
Get with the service manager at that dealer and tell him you’re losing confidence in their ability to repair this problem.
Have you been a lucrative customer to that place? If so, tell him they’re going to lose you as a customer if they don’t get this handled ASAP. The prospect of losing a “cashcow” may motivate them to put their best guy on it.
Can you apply the lemon law? Has it been there enough times unsuccessfully for the same problem?
Just a bunch of ideas . . .
The warranty expired in October, but because I brought it in in September for this problem, it’s covered.
I’m looking at the papers from the dealer that explain what was done - none of the codes are on them, so I’m not sure what the codes are.
There was an internal leak in the valve cover - they replaced that. They replaced the mass air flow sensor. They replaced the pre cat 02 sensor (apparently it had a malfunction). The first time, they just reset the light because apparently it was a gas cap code.
This time they called me and basically said they had some ideas, but were not sure because the light went off before I brought it into the dealer. It was on for a week. I brought the car in on Thursday afternoon, and as of now, it’s still there.
Do you add gas after the pump handle shuts off? If so, you are getting raw gas into your charcoal canister and that is causing the CEL. As the canister purges itself and dries out, the CEL will go out.
That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.
@Keith - I don’t do that.
The CEL doesn’t come on after filling up the tank. This last time, it didn’t come on until the gas tank was about a 1/2 empty.
It sounds like it’s a EVAP code, but post it/them here. Your last bit of information strongly suggests this.
I don;t have access to the documents for your particular car, but I’ll post my own just for illustration of my points.
The gas tank is designed to be able to breathe in and out through a charcoal canister. The canister catches hydrocarbon molecules. The emissions system has a pressure sensor that measures vacuum in the gas tank. A slight vacuum is maintained to prevent hydrocarbon molecules from escaping. If that vacuum gets too high or too low, the pressure sensor tells the ECU and a Check Engine Light illuminates. The fault codes stored in the ECU then tell the tech that the EVAP system has a problem and gives him an idea what it might be. The idea is that he’ll diagnose from there. The problem is that far too many techs don’t understand the EVAP systems well and don;t want to work on them. So they attribute every leak to a “bad gas cap”.
The tech should be able to access for your car an on-vehicle inspection protocol for the system, similar to the one I’ve attached. Don’t be afraid to ask him.
In the meantime, if you’ve been “topping off” your tank, it would be a good idea to discontinue this practice. In some older vehicles, fuel can get into the charcoal canister and prevent the system from breathing on as the gas is pumped out.
http://tijil.org/Scion_Docs/Scion_06_misc_docs/2007sciontc_ncf%20Folder/2azfeemi.pdf
http://tijil.org/Scion_Docs/05_tC_Shop_Manuals/Repair%20Info/Repair%20Manual/Emission%20Control/Emission%20Control%20System/onvein40.pdf
You need to contact the dealer and have them dig up those previous fault codes. Insist on it, because you’re concerned that they’re not getting a handle on the problem.
Ask them to physically look in their files.
Keep meticulous documentation, just in case they “fix” it, only to have the exact same problem occur a month later.
If they do tell you they’ve fixed it, ask them if they let the monitors run to completion after clearing the code(s). Don’t let them just clear the code(s) and hope for the best.
If there was/is an evap problem, ask them to show you that the car passed an evap service bay test, if applicable. I’m not sure if the Mini scan tool has this feature.
Have you checked for rodent damage to wires and hoses? Mice have attacked my Mini four times now…wiring harness, evaporative hoses, fuel pump, radiator, connectors…you name it.