sorry for bringing up an old thread but my car seems to only have this metalic sound (when hot) as soon as the starter releases and the motor fires. (a couple of milliseconds).
i was hoping that people that have had this problem will chime in.
thanks

 

I have the same problem as well. On startups where the engine has sat for more than 12 hours, immediately after the starter fires the engine makes this same rattle. Took it to the dealer; they stated the oil dripped off the lifters and it was "normal". It stops immediately after the engine starts to idle after the initial revs.

 

I had the exact same noise. It was a screech. a metallic, annoying, i hope nobody notices me, loud screech. Diagnosis: you need a new starter motor. Just to inform you, mine did not depend on long term parking, or hot or cold weather. It did it say...one time every 10-15 startups. (About 1-2 days worth for me). Then more often, and more often... yada yada yada... EVERY DAMN TIME I STARTED THE CAR!!! I would actually wait for people around me to be out of sight before i turned the engine over because it was, well... embarassing as hell!!! I had mine changed for the uh-hum reasonable price of $457.00 (price/labor). It took my guy about 4-6 hours. No engine removal needed, but he showed me where the part is and to be quite honest, it looks as if it would be easier to do the job with engine removal.
Anyways, now I can hear only the beautiful startup purr than only a p-car can make. No more screeching noise. Good luck

Peter

 

thanks guys.
i can confirm the following.
- the car has stood for about 4 hours and i went to start it. no noise...
cranked it about 5 times in succession and i can hear the noise comming back.

- i dont think it is lifter noise and it is not a belt "shriek"

sure it is starter related....

oh..it does it all the time when hot.

 

$5K to change a starter in this car!? That's Ferrari-esque!

That alone convinces me tol get a zero deductable full coverage extended warranty for this car before the factory runs out...

 

I assume you have ruled out the LIC plate banging sometimes at startup?

 

On 3 occasions, I noticed a light puff of white smoke in my exhaust for a few moments after starting the car. On all three occassions, the car had been sitting idle for a week or more.

On another occassion, I shut the car down while it was still hot from a session on the track. I NEVER did this to my car before (I always took a cool-down lap before killing the engine) but a unique set of circumstances caused me to do it this time. After the engine ran for a few minutes, all signs of the smoke disappeared.

So my questions are simple.

1) Is it normal to see white smoke in the exhaust in these circumstances?
2) What exactly is causing the smoke?
3) Is it possible to damage the engnie by shutting in down while it's still hot from a track session? If so, why?

 

Thats completely ridiculous. You dont need to drop the motor to do starter. It is a bit of a chore to get to but its almost just as bad with the engine in. I wouldn't go back to that shop again.

 

On Mercedes engines a metallic rattle at start up is from the cam chain tensioner slightly collapsing. The chain briefly rattles until oil pressure builds and tightens the tensioner. Sometimes if the engine stops with a valve lifter part way up a cam lobe, it will put tension on the chain and will tend to collapse the chain tensioner more. I think my turbo sometimes does the same thing. I don't think it's a problem.

 

I get a knock or two when starting the engine when its warm. I assume that the knock sensor is not online yet (no sense messing with the cam timing when starting the engine is a priority) and there's some detonation. It stops in less than a second.