Today I moved my car in the garage from left to right to get access to my snow blower. About 4 hours later my wife went to start it to move it back and it wouldn't start. Then when it finally did start it was close to stalling and the idle was down around 250 rpm. It also smelled terrible, like rotten eggs (sulfur). I tried to ramp up the rpms towards 700 which it got to and the dash lights returned to normal (they were sort of flashing). But then it promptly cut out.

So I restarted and everything seemed fine.

My questions are if anyone has experienced this and if anyone might know what the cause is?

I drove it around for about 5-10 minutes and it seemed to behave just like normal.

Thanks.

 

Maybe there was something that got into the gas.

 

+1... Sounds like some bad gas or moisture in the tank. Add a can of dry gas. It can't hurt...

 

perhaps it was the gas? Come to think of it my wife did refill the tank the night prior (about 1/2 a tank).

I'll drive it today. Hopefully it'll be OK.

 

well I drove the car the last two days. It runs fine. But at startup there is still a hint of rotten egg smell. Is this from moisture? Or just high sulfur content in the gas I got?
Or could this be due to lower octane fuel, and spark retardation?

 

What octane are you using? Its recommended you go at least 91, I go 94 personally. High ethanol also isnt too good either. Rotten egg smell wise, there could possibly be something stuck at your exhaust like plastic bag as it has happened to someone's mustang on another forum.

 

I'm using 93 or 91 octane. I'm concerned that my wife filled up a few gallons of 89 octane by accident since we put that in the van.

 

Ah quite possible with wifeys. The knocksensors were prob goin crazy with the difference of octane after it settled overnight (mixing is better) but yeah won't kill the engine but just let it burn it all up and then put back in the proper stuff.

 

Rotten eggs is a bad sign. In the old days it simply meant that there was lead in the gas which cased the cat converter to fail. Now it means that the trim levels or the fuel/air ratio is at fault. Most likely the ECU is getting a faulted sensor reading from one or both of the upstream O2 sensors and is causing the cold start valve to function incorrectly.

It could be gas that has a very high ratio of alcohol ( too much ethanol ) causing the system to fail. That's a simplistic explanation of very complex system.

Bottom line, if you haven't the skills to work or properly dx the system, its time for a service visit!

 

So you think I should take it in?

There was still a faint smell of rotten eggs this morning. Nothing like what happened when it stalled though. That was terrible.

So do you think it's just bad gas then? Or a combination of bad gas causing the ECU issues?

Edit: would this be covered under warranty?

 

OK. I called our service dept. I was told that this happened because I ran it shortly and turned it off. Due to the rich mixture during startup and then prompt shutoff it flooded the system.

I was also told that as long as there isn't a check engine light I should be OK. It will take a few days for the excess gas to work it's way out of the cat converter. If I still smell it after a few days then I should check back with them.

Interesting.

 

sounds right, i mean retarded ignition would possibly push gas into the exhaust (which will happen with lower octane is used I believe)

 

Yes, like I said, "the trim (fuel/air ratio) levels" are the issue. But what you did should not flood the system unless something else is not functioning right. Depending on the mileage you have, make sure you're using a good grade detergent fuel. 89 vs 91 octane isn't the issue either. I'm placing my money on either a faulty O2 sensor or cold start valve. They could be dirty. Try a different gas company and keep your receipts. If it happens again, go to the dealership with your receipts. The dealer may have had other complaints about that station.

Good luck!

 

As you said: Interesting.

"- get access to my snow blower.” means that you are using the GLK in a cold environment. Then F18BENs comment with regard to moisture in the tank is a reminder: It’s good practice to keep the tank (well) filled all times during cold conditions, to prevent condensation, which may occur driving in the cold / parking in a temperate garage. I am aware of the fuel consumption of the 350s!

The smell of rotten eggs is "strenghtened" by the catalytic converter needs time to reach its operating temperature.

Hope it works out for you.

 

On a second thought: Did you check Vehicle Status Message Memory menu of the Multifunction Display for any malfunction - or warning messages?
I guess the issue is not shown there, as messages for the owner are not very detailed. A comprehensive readout can be done by the M-B Service department.

 

I didn't check the Vehicle Status Message Memory. I'll have to remember to do that. The tank has been kept well filled. Usually it doesn't get past halfway, so I doubt that should be an issue. It's been filled every 3-4 days.

I guess the issue as I was told, was that I started it, ran it for about 20-30 seconds and then shut it off. I spoke to two different service advisors over the phone and they both said the same thing. Now, perhaps they checked with each other while I was on hold but they were at least consistent.

Their basic explanation is that the fuel air mixture was very rich due to the cold weather. And then not letting the engine run for more than a short time left excess fuel in the system.

Mileage on the car is very low, only like 3k.