medjunkie

The dreaded check engine light is on. Not blinking. What could be wrong? Will call tomorrow morning!

Bob Z.

iTrader: (1)

Check your gas cap....

medjunkie

I haven’t even put gas in it so far! Only 140 miles so far

Bob Z.

iTrader: (1)

And that is exactly why you should check it...salesman probably did not tighten it when they filled it up for you!

medjunkie

Ok just checked it. It was closed. I redid it and will drive and see if it goes off. Will report back.

Bob Z.

iTrader: (1)

If that was the problem it will take a few cycles for it to clear. I read that is the most common reason by far for a CEL. Or stop by one of the auto parts stores that will read your CEL for free.

medjunkie

light didn’t go off. I will cycle it a couple more times and see. Hopefully it’s nothing big. How many cycles did it take for your light to go off? I haven’t seen any change in performance of the engine such as higher revs or anything else. The onboard computer is oblivious to anything going on either.

Bob Z.

iTrader: (1)

If it was the cap that should have taken care of it, sorry.

streborx

A good reason to buy an OBDII scanner -- even a low priced one will do. When you visit an auto parts store to get a free scan ask what they stock and recommend.

medjunkie

Took it to dealership. Being told it was something to do with the the “evaporator system”. Possibly gas cap related. Couldn’t find anything else. Hopefully stays this way.

300SE1993

That tells me they may have overfilled the gas tank and soaked the evap system. Just a thought. No CEL on mine in over 1K miles.

medjunkie

So check engine light came on again! I got an OBD2 scanner and it could not find any modules giving out errors. I tried resetting the light but it wouldn’t do that either. So I’m stuck without options other than taking the car in to the dealership again, wasting 2-3 hours and being told that nothings wrong. Any suggestions on what I can do? I got an Ancel OBD2 scanner from Amazon. Thanks!

hard top

Take it back and tell them the problem isn't fixed.
Typically, OBD2 scanners can check some codes across all brands as part of an industry standard. But there are proprietary areas and PIDS in the vehicle that either require additional software with a software license to access or a hacked version of that software. Hopefully that is not your issue. Either way, make the stealer fix it.

streborx

What's wonderful about the OBDII "standard" is how many there are. Have the dealer give you a new gas cap. Maybe yours has a bad/damaged seal.

Festertester

Guys, it s new vehicle- instead of trouble shooting just take it to the dealership workshop under warranty

Jassa105

Guys,

I got a 2021 g63 with 600 miles
and second time engine light has come due to cylinder misfire?

Theyre reaching out to germany for next steps any insight on this?

medjunkie

Dropped it off at the dealership again today. Turns out it’s not the gas cap. Rather there is an emissions leak and they need to figure out where. Gremlins! Will keep y’all posted on how it goes

medjunkie

Update: replacing purge valve... whatever that is.

Hodog16

Good info thanks. Hopefully this fixes it!

medjunkie

After changing the purge valve and the charcoal canister, the frickin light went off again! Took it back in and now they will change the fuel tank.. they can’t seem to find any other leaks. Thoughts?

streborx

Is the service manager using a genuine Ouija Board for diagnosis or a cheap Chinese knockoff known to be unreliable? Seriously, how are they troubleshooting this - changing out one component at a time hoping to get lucky?

medjunkie

LOL! Sounds like a Ouija board. The error code is the same each time. My honest feeling is that it’s a bad sensor.

Floobydust

The dealer needs to put away his Ouija board and do a smoke test on the truck. This will pinpoint exactly where the leak is rather than just randomly replacing things. There are three active components to the evap system (purge valve, the canister vent valve, and tank pressure sensor) and four passive ones (gas cap, charcoal canister, vapor/fuel lines, and the tank). A smoke test (with the Star system to cycle the valves) will diagnose all of them except for the pressure sensor, which would a diagnosis by exclusion of all the others.

streborx

Changing out the fuel tank is not an "enjoy an espresso in our customer lounge while you wait" service procedure. Have all the other usual suspects been ruled out, or is this just another shot in the dark? I agree with the smoke test diagnostic - it's the only way to locate a leak if it exists.

medjunkie

so they did the smoke test which is how they discovered the purge valve. Before they change the fuel tank, I’ll ask them to check for a leak again. They weren’t able to identify leaks anywhere else.