MaroonC63

Long story short, i just got my car back after a month long wait and was on the hway and sped from 60-120 ( i dont need lectures, the road was completely empty) and when i slowed down the car kept slowing down untill it went to a complete stop, i kept pressing the gas and it wouldnt accelerate. Anyone know why this happened? Just seems weird that it happened out of nowhere when the car was running fine for the two days i had it.

cls55

Was it tuned ?when you say complete stop,did the engine die?more details please.

MaroonC63

Yes its been tuned since 2012. Engine didnt die, it just kept slowing down till 0 so i put it in park and turned it off. When i try to turn it on it struggles while its cranking then just stops cranking.

m a x i m u s

Maybe the cops in your area have some new technology to stop speeders. Jk. That sux. Sounds electrical. Maybe a bad alternator?

cls55

Was the car responsive to the gas peddle before you shut it down?check engine light?

sloanbj

You are lucky to be alive! Perhaps the motor overheated.

MaroonC63

Nope it wasnt responsive but a check engine light did come up. Wasnt overheating thats for sure, the gas peddle just wouldnt work and i barley got over to the emergency lane.

jellis102.com

Catalytic converter can cause this issue, I've experienced these symptoms way in the past, (just a suggestion)?

khmergod

Scary situation. Glad you're safe.

aamirani

Go down to Autozone or something, or use an OBDII reader to figure out what the CEL code was.

MaroonC63

Well i am catless. Could that be it?

MaroonC63

Thanks buddy!

aussie e55

hi do u have elec. power dash light up/headlights/horn ? does it crank over ? this should yell u if battery at fault. just yesterday stopped for fuel & car would not crank over had all lights turned out to b ignition switch was told common problem on c class

tfthach13

If your engine wouldn't turn over, I think it's the crank position sensor. I've had that happen on my parents' S430.

As for the engine not responding and slowing down on the freeway, I'm not sure. I've had an instance where I was coming to a stop from some spirited driving on the freeway and the traction control/stability control malfunctioned. At this point the engine was still on but I couldn't accelerate; as if the gear was in neutral. It also felt like the brakes had locked up. I turned the engine off and back on and everything was back to normal.

Not sure if this pertains to your situation, but I help this helps. :/

jvanbrecht

If you want, I have an OBD reader, and I see your car often enough in Balston where I work, usually at Pot Belly or Chipotle.. Your welcome to borrow it.. its a basic model, will give the codes, you will have to look them up.

I just got my car back from the Dealer on Wed.. They practically replaced the entire fuel system (sensors, rails, pumps for the second time), steering column (apparently the car stopped working at the dealership, I did not drop it off for that), drivers side tail light and associated harness and wiring, and a few other things, they had my car for 2 weeks (thankfully it was warrantied)

MaroonC63

No lights came on, just the CEL and check tire pressure lights. The gas peddle wasnt responsive at all, it just slowed down like i had my foot off the gas gradually and luckily it made it to the emergency lane right before it stopped. It does crank, like its so close to turning on and then splat. Nothing.

MaroonC63

Hey thank you very much! I wish i could say the same about seeing your car ( congrats on getting it back, its a great feeling) we need to strengthen the amg community around here. I go to school in ballston so im there on the daily lol. My car is now at the shop and will be looked at tomorrow! Ill update you all with whats going on once i find out! Thanks all for the replies

jvanbrecht

I usually park on the side where you have to reverse in at the Qwest building where Pot Belly is.. you can tell it is my car, steel grey with smashed fog light, cracked lower mesh grill, and a bunch of paint chips in the hood Driving through DC every day takes it's toll.. Not fixing the aesthetic stuff till I change contracts and have a shorter drive.

ryanC63AMG

Could it be the fuel pump?

CoolBDPhenom03

I heard about the S-Classes having issues with shutting off under hard braking. It was an electrical flaw, but it would start again, so it doesn't sound like the same issue.

G55AMG

I think is the Throttle Position Sensor.
JV

roadtalontsi

wow great internet diagnosing.... throttle position sensor has 2 sensors in it so it has a failsafe which will be delayed but will still work. crank sensor will allow the car to crank but not start. never heard of the s-class dieing under hard braking sounds like an isolated issue. fuel pump sounds possible. could be rats eating away at your car while you sleep too.

tfthach13

If you read back to what I posted, you will see that I was addressing the part where the engine was not turning over. Not the engine dying on the freeway. It could be a multitude of issues with the OP's car; not just one.

People are merely chiming in because they may have some experience with it. What makes your "internet diagnosing" any better than ours, Mr. Auto-WebMD?

CoolBDPhenom03

Happened to my buddy's R8. Cost him $1k.

MaroonC63

It was the fuel pump! They replaced the crank sensor's also. cant wait to have it back! Thanks guys, ill keep rat poision all over my driveway