jctevere

Ok, this just happened 5 minutes ago... I haven't started my car in about 4 days. It started fine when I left my house. If anything it somewhat sounded like a weak battery and it rolled over one time more than normal if at all. But I got gas (turned off the car) and filled it up with premium at a station that I frequent. But when I went to turn it back on. The car startedvery badly. And the rpm needle was jumping up and down and the car was shaking to the point of where I felt it in my seat. I was like WTF. Anyway, I pulled away hoping it would go away and the check engine light began to blink (I thought it was suppossed to be steady on). I turned off the car and started it right back up. Everything was fine. Does anyone know what might have happened? Should I ignore it? My car has never done it before. It has had some tough starts where it seems like the starter apps turning over prematurely. And the engine starts delayed and weak at first. But idles normally 2 seconds later. Basically, what the he'll happened?

NuMBS500er

It usally happen after refueling, it has to do with the vapor pressure in the gas tank that cause the computer the put the check engine light on. Of that is the case, you can just unloosen the gas cap and retighten it that would shut the check engine light off.

ohlord

check engine light off now?
Check your gas cap is on properly.
Don't top off your tank if that is a habit.
If the cel blinks again better get the codes read as a blinking cel indicates possible engine damage if you ignore it.

jctevere

Thanks for the quick feedback guys! The check engine light was blinking, and when I turned off the car and restarted it, it never came back on. I wonder if I go to the dealer if the check engine light will be stored in some type of memory bank as past error codes thrown?

Thinking back, I did start the car pretty fast, in fact, the gas cap might not have even been put on all the way yet... The engine was puttering, bouncing anywhere from 500-900 rpm, and the check engine light was blinking. I thought that if there was an error, the check engine light would just stay on. This is very bizarre and has never happened to me before. I think I might just go into the dealer and tell them my experience.

Why is it that you say topping off the car is a bad thing? It clicked at $39.65 and he filled it up to $40. I usually always top off like that...

EDIT: After doing a little bit of research, my symptoms plus the fact that the CEL was flashing sounds like my cam and crank were out of sync. Any reason why this would randomly happen and then stop? I'm going to go to call the dealer tomorrow and see what I should do.

C300Sport

I would visit the dealer at the first opportune time and ask them to pull the codes. Better to know what was going on that to hope everthing is fine.

jctevere

Ok, I spoke to my service advisor. He pretty much said that it happens when you start in cold weather starts and that it is common for an engine to misfire in the cold, especially when you get gas?... I think he is just BSing me, but it hasn't happened again. If he is right, that is ridiculous, any other car I have ever had has had misfire because of cold weather like that... From cadillac, infiniti, honda, hyundai, mercedes, etc... I wouldn't be so worried if it wasn't so violent, my car was literally having a seizure, and I was shaking pretty violently in my seat. If it did it in 40 degree weather when its left for 3-4 days, what will happen if I go to start it after a 2-3 week vacation in the dead of winter...

RLE

Better stop by the dealer for a stored code check. A few weeks ago my check engine light was on and off all day through numerous starts during which the idle was a tiny bit rough.

Turned out it was the left exhaust camshaft solenoid which was replaced and all is now well.

OneOfaKindTrini

Or instead of getting robbed by the dealer take it to Autozone and have them scan for the codes and then find out what it is. I haven't been a CEL blink before.. I have heard of it, but not seen it.

Petmerctech

CEL blinks when the engine is misfiring on hard acceleration under load.

C300Sport

To simplify, a steady on CEL means you should have the car checked out at some point. A blinking CEL means you should pull over and turn the car off.

noka

2009 User's Manual mentions nothing about blinking CEL, only whether it comes on or not while driving. Where did you get the information?

Petmerctech

I should clarify. A flashing CEL usually occurs under acceleration and means one or more of the cylinders is misfiring enough to damage your catalytic converters.

dcjwlee

Sounds like a misfire. Pull the codes to be certain. Had this happen in a loaner, probably because people out ****ty gas in and run it like a race car. is your c a cpo?

A blinking cel signifies a mechanical problem that you need to pull over and shut down asap. A solid cel can mean a variety of mechanicas and electrical issues

jctevere

The c-class was brand new. I always put premium in it. Mobil or Shell, but lately I have been using USA premium. The car runs much better and better gas mileage.

The error was a engine misfire. I think it had something to do with I just started as soon as the gas was done and before the cap was probably closed --- oops. But I was freezing and wanted the heat on ASAP. It hasn't happened again, I just dismissed it off as normal, and if it happens again I will pressure the dealer for more than an answer of "it happens".

That being said, I do run my car pretty hard. Why not, thats what they are used for. After 20,000 miles the car still runs like new... I wish I could have said the same for my older g37 coupe...

dcjwlee

Gas, spark, or timing and its not the gas. They should be able to tell you what the problem us before it happens again.

encoder

To answer those who asked -- a blinking CEL is universally (across all makes and models) an indication that very bad things are being detected and you should stop the car and turn off the engine as soon as is safely possible.

In most cases of an O2 sensor (loose gas cap, etc) it will come on solid. That means "meh."

Blinking means "oy".

BlackjackM

I thought I read somewhere a blinking CEL is a loose gas cap- I'm sure I've seen that?

edit- it's a blinking low fuel light I was thinking of