C36, C280 clatter on cold start up

[Three Point 6]

Got a question to all fellow M104 engine owners. How would you all rate how loud your motor is when you start up cold in the morning. Mine sounds like a diesel sometimes and I heard it was normal. Whats yalls experience??

[vas2vas]

yeah it runs like that at cold start up... fan runs at full speed first minute or so and delayed trasmission upshifts till the cat has warmed up... it's all part of the car's programming...

[Andrew C280]

-25 out today my C280 just hums a way, you can even hear it so quiet.

[pnsji]

everytime i start the engine (cold start), It start just like when it is warm.... not sure what you are hearing....

[davis449]

I hear it when I start mine every morning, warm or cold. Sounds kinda wierd...like a diesel, yeah.:D Oh well, it gets the job done.

[Three Point 6]

It only lasts for 1-2 seconds, but I heard it is due to all the valvetrain up top. Quiet & smooth running after 2 seconds though.
Davis449, Glad to hear I'm not the only one w/ that opinion

[MRP Motorsports]

Originally posted by Three Point 6
It only lasts for 1-2 seconds, but I heard it is due to all the valvetrain up top. Quiet & smooth running after 2 seconds though.
Davis449, Glad to hear I'm not the only one w/ that opinion

It is the hydralic lifters making noise. It can be from too heavy oil for winter driving? Also check the oil pressure.

[martattack]

Mine doesn't really make any noise other than the smog pump for the first 10 seconds or so.

[JBENZ]

i hear the same thing every time i warm it up, makes me wonder if there is something wrong with the engine, but upon hearing from some you guys i guess it normal.

[C280 JR]

my car begins to wistle as soon as i turn it on, and then it fades away, mabye its because i turn the heat on right away so that the car can worm up for me a little bit before i get in it

ELvir

[J Irwan]

I am not sure by "diesel sound" you guy referring to...?

My car doesn't have diesel engine sound even when startup in a very cold morning


all it does is it make high-pitch whine (it always do that the first 20 sec it startup in the morning in winter or sumer time).


And I always drive the car at least about 15 sec after the whine is gone..



Regardz,

[kameraguy]

I don't hear any clatter when I start my engine....just sounds normal as when warm. I do hear the high-pitched whine that J referred to. I just let the car idle for about a minute until it goes away and drive off.

On idle, the engine does make a SLIGHT clatter, but it's not noticeable unless you are really listening for it.

Maybe it's the same noise?

[jnolte]

Yeah on my ole C36 i would get a Diesel sound sometimes, but when i chaged the oil to a thinner consistancy it wasent so noticable. I also had the hi pitch whine at start up

[martattack]

Originally posted by J Irwan



all it does is it make high-pitch whine (it always do that the first 20 sec it startup in the morning in winter or sumer time).


And I always drive the car at least about 15 sec after the whine is gone..

I'm almost 100% positive that is your smog pump that is pumping air into the exhaust to help burn the unburned fuel on startup. It is perfectly normal.

Martin

[jnolte]

I was thinking it was the Vacum pump

[Dan The AMG Man]

My C 36 sounds like a diesel as well.. running 10-30 and temps are 5 degrees now.. -10 or so with windchill.. the rest of the day it is better..

[cian36n]

I know just what you guys are talking about, the quiet diesel sounding noise. I've heard from a few guys (besides this thread) that its normal, so I'm not worried.

[hocky]

Mine is only the smallest brother here a Euro C180 and the 4cys do make a noise on start up especially when cold. The noise quietens a few minutes later, but it certainly does not hum along smoothly like a C220 I tried last year. That one was smooth humming even from cold starts and sounded so luxury class. Mine sounds diesel like even though its not. Makes more noise when I take off a bit hard. If I take off slowly it is quieter. The first gear change from cold is always very disappointing unless I try to anticipate it by driving slower instead of stepping on it. Very disturbing and friends wander if its going to breakdown.