Engine Rattle at Startup

Dec 18, 2007 | 12:33 PM

walker29

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Joined: Dec 2007

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From: OC - USA

2023 EQS 450+

Engine Rattle at Startup

I just picked up a C300 Sport about two weeks ago. The engine has about 800 miles on it so far, and I'm wondering if it's normal to hear the engine rattle for a few minutes on cold startup. Is this normal with MB engines? Is it just because it’s a new motor? Once the car is warm it runs smooth as silk.

The car is parked in the garage, and I live in California. We're not talking freezing cold by any means.

Dec 18, 2007 | 12:35 PM

howie

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Joined: Nov 2007

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From: 954

01 CLK 55 AMG

something loose on the exhaust maybe??? Bracket or hanger or something?!?!

Dec 18, 2007 | 12:43 PM

walker29

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From: OC - USA

2023 EQS 450+

It sounds more like it's coming from the motor. It goes away when its warm and isn't there when I start the motor after I've driven it.

Dec 18, 2007 | 01:31 PM

CarGuru

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Joined: Aug 2007

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'08 C 300 Sport, '01 SL 500 & '08 Nissan Frontier SE Crew Cab 4WD

Quote:

Originally Posted by walker29

It sounds more like it's coming from the motor. It goes away when its warm and isn't there when I start the motor after I've driven it.

Our C300 Does it too, goes away as soon as the T-Stat opens. I think it's normal. Equally weird is how the exhaust sounds like a small block chevy with aftermarket mufflers for the first 15-20 seconds from a dead cold start.

-Ryan

Dec 18, 2007 | 01:46 PM

walker29

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Junior Member

Joined: Dec 2007

Posts: 29

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From: OC - USA

2023 EQS 450+

Quote:

Originally Posted by CarGuru

Thanks Ryan,

How many miles do you have on your car?

Dec 18, 2007 | 02:13 PM

Lakerz4sho

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Joined: Sep 2007

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c300 sport

i noticed this in my c300 as well (~1100 miles)..

when i start it up in the morning, i notice that the enginge rumbles a little bit, and even shakes/vibrates the car gently for a few seconds, until the rpm drops and then it runs smooth the rest of the day.

Dec 18, 2007 | 03:08 PM

MBTex

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Joined: Jul 2007

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From: San Antonio

2008 C350

I have the same little noise at start up. 2200 miles now and it has always done it. Going to take it in for the "check up" servicing and I'll ask about it, but I believe it is normal.

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Dec 18, 2007 | 03:49 PM

walker29

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From: OC - USA

2023 EQS 450+

Thanks for the replies. Looks like this a common issue.

I was starting to wonder if I needed to hit the Slick50 or not

j/k

Dec 18, 2007 | 09:05 PM

#10

nyca

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this is somewhat common in newer cars as the emissions systems struggle to get temperature into the catalytic converters as quickly as possible.

Dec 18, 2007 | 09:28 PM

#11

rb23lb

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LOADED 08' C350 & 14' GLK-350 Diamond White (P1, MM, AMG Pkg, Ln Trkng, Htd Sts, Keylss Go)

Quote:

Originally Posted by CarGuru

noticed same thing on my c350, seems normal after a few seconds, nothin to worry about right?

Dec 19, 2007 | 02:49 AM

#12

dion

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From: Upland, CA

08 C300, 04 Sienna XLE LTD AWD, 00 BMW M Roady, 98 SVT Contour

I already took my wife's c300 in for first service (3100 miles) and I've noticed it from day 2. I mentioned it to my SA, tech checked it out and stated it's normal.