Unbelievable...

I was driving home this afternoon after picking up the kiddies, going through a slow area with lots of stop signs. At one of the stops, I heard a horrible sound. I looked behind me and remarked to the kiddies, "Oh my gosh! That guy behind us has some SERIOUS problems with his car!" It sounded like back in the day when if you turned the key to start with the engine running you'd hear that loud, grinding, screech from the starter, but LOUDER!

At the next stop sign, the eco stop kicked in and the sound stopped. A few seconds later it was my turn to go and when the engine started back up, so did the screech. Then I saw a construction guy looking at me like I was some kind of monster. The faster I went, the higher the pitch went. I suddenly thought, "There's no way that sound is coming from my new Benz (1914kms)."

It was.

I stopped to figure out what the ... was going on. Looked under the car, in the wheel wells, at the exhaust, and didn't see a thing. I got in the car and revved the engine (in park), but the sound was gone. I tried it in reverse, drive, a few times, but it didn't come back. The sound from the engine seems to be slightly louder, though. It's not as smooth and quiet as it always was.

I have an appointment tomorrow with the dealer, but would appreciate any ideas... (I have never heard anything so terrifying! I thought the guy behind me was going to drop his engine in the middle of the road. But it wasn't him. IT WAS ME!!)

 

Sounds like a loose belt. Hopefully.

 

Thanks, but perhaps my description wasn't optimal.

It sounded as if someone was holding an empty aluminum can against the alternator fan. It changed speed directly related to engine RPMs. I've heard loose belts plenty of times and this was different. It was very much a metallic grinding sound.

 

Sounds BAD. Pump? The rpm dependence thing makes me still think of something driven by the belt or a busted turbo ..... let us know. Unlike the guy with the check engine light your problem is one I wouldn't even run the engine never mind the car. Sounds like a tow ride to the dealer is in order.

 

Well, I drove her home (about 15 minutes) and plan to drive the 15 minutes to the dealer this morning...

Wish me luck.

Btw, I was thinking turbo, too, but this being my first car with turbo, don't know what to listen for.

 

I forgot to mention...

There was no error message at any time. Hopefully the dealer will be able to find one.

 

A screeching metallic noise that varies with rpms.........

 

Yes. That's how I feel.

Of course, I'm at the dealer now and they can't find anything wrong...

 

Yes. That's how I feel.

Of course, the dealer couldn't find anything wrong...

I am, of course, kicking myself because I had the audio turned off on my car cam. I can clearly see where/when it happened but can't hear anything.

 

Hey, there's no codes how could anything be wrong????
Mechanics are getting worse all the time.
Hopefully it was nothing serious. Maybe a stuck foreign object that made its way out by itself.

 

Yeah, there were no codes. I made them check everything a second time, they still came up empty. I'm guessing the foreign object explanation to be the most logical.

Anyway, she's driving fine now. Hopefully it will remain a mysterious anomaly. If not, I'll have video WITH audio evidence.

Appreciate your support, c4404matic.