gpace1

We leased a C300 two weeks ago. Has about 450 miles on it. Since it was new, it has a cold start noise that is troubling. Like it's low on oil. Not really a tappet noise though, more like a bearing noise. Noise sounds "throatier". Goes away in about 3-5 seconds. Only happens in the morning after she sits overnight. Oil level is correct. No other symptoms. We are south Texas so it is hot. Garage gets over 100 degrees regularly. Could it be the timing chain?

oblu

Mine sounds like a diesel when it first starts up after sitting overnight, doesn't matter if it's cold or warm. Mine's leased also, and my dealership service dept seems to have the attitude that if it isn't physically broken then there's nothing wrong so I'm leaving it alone.

Germancar1

Normal sound with DOHC, multi-valve engines. It goes away after the engine is warm, if not then it may be a problem, but I seriously doubt it.

M

oblu

Uh, not on any of me previous six cars, or my other current car. All dohc 4 valve variable timing. All started and idled smoothly cold or warm. This one sounds like a tractor engine.

Maybe this is normal for mercedes engines? I know for a fact it's not for other manufacturer engines.

narky

Mine doesn't make a strange noise at start or idle (yet), but it occasionally (1 out of 4 times) makes a disturbing shudder when I shut off the engine. It kinda sounds like the engine is "puttering" to death. Like a Ford truck, maybe? Nice.

I hope that's normal too...

jrct9454

Well, once again, I don't know what's going on, I guess - ours starts quickly and sounds like every other gasoline engine I've owned over the past 45 years. It idles smoothly and shuts down smoothly. Assuming you're not using inferior fuel, I'm mostly clueless about these issues - the shutdown shudder might be understandable considering these are 90 degree V6s that depend on balance shafts to keep the shakes at bay, and you CAN trip them up at shutdown if the pistons are in just the wrong phase when ignition is cut.

Ours continues to be the best car we've owned, and I've had 50+ cars since 1962. Idle smoothness can't be compared to a straight 6, but I have no complaints about the way it behaves.

QQQ

Agree. Nothing is silky smooth as a straight 6. I miss my old C280.

keith100

I've now started mine at -20C and plus 32C and it just quietly starts and goes-and I park it outside. Garage is too full

If you start up in a "hard walled" (brick or concrete) garage you get all sorts of reverberation noises. I park in an underground garage at work and all three of the last cars I owned made weird noises as I went down the ramps, close to concrete walls.

If it is something else take to the dealer.

schvamf

Mine does this too first thing in the morning but only lasts for about 1-2 seconds during start. Not really worrying about it since my's a lease.

maninblack

this is not right , you may want to change dealership or get the service manager to look into it if the advisor is not helping you . it is not normal to have that kind of noise during start up

gpace1

Thanks for the replies. I took "Ethel" to the dealer yesterday. "Clean bill of health". As an ex typewriter repairmen, I am well aware of intermittent problems. As such, the advisor requested I leave the car overnight so they can replicate the symptom. I passed. He suggested if it gets worse, to bring it back. At least it's recorded. CYA

On another note, does anybody know if this car has a compass. It has P1. No MM package.

One thing continues to rise to the top with this car. It's intuitive. Seems like whenever we reach for something, it's there. Except for the turn signal.

ISPEEDM3

Yep , took mine to the dealer and left it overnight as well.. they said nothing was wrong with it and didnt find anything at all... hummmm weird


to the post up top, yes the P1 pkge does have a compass, you just have to mess with the stearing wheel buttons to get it to show.

RLE

Do you mean, a deep knock-knock-knock until the oil pressure comes up (using your imagination since there is no gauge)?

I won't go further until I hear more.

gpace1

Yes, kinda. 3 to 5 seconds.

CarGuru

The only weird "cold-start" things ours does is first thing in the morning for the first 10-15 seconds the exhaust sounds like an SBC expelling grasses through a tru-dual exhaust. I actually hate to warm the car up because then the cool throaty sound goes away just as the choke opens up a few moments later. Think I'm crazy start your car up cold from sitting over night and immediately run to the back of the car, sounds like there is 500 hp under the hood for a few seconds. It was so noticible my wife & I were visiting my folks on a cold January evening, when we left my folks came outside to see us off and my mom actually said "did you change out your pipes"? I said no it makes that sound for a few seconds then goes away. Also there is a metallic spinning sound that goes on for a few moments then fades away. I've actually heard the same sound on another W204 so I'm not worried. Good luck with the dealer, the noises the OP described do sound un natural to the W204 though, get that looked at for sure.

-Ryan

itcrashed

I get the same thud-thud-thud as I start it - only after it has been parked overnight. It goes away after 3-4 "thuds" I never really thought it was a bad sound. I let my car sit for about 15-20 seconds until the fluids are all kicked around...then I drive normally thereafter.

gpace1

Thanks for the replies folks. Really loving this car. It belongs to the wife. Mine is a GMC Sierra 2500 Duramax/Allison. I took her (the car) out to the Texas hill country yesterday. She can really straighten those curves. I really hope the engine noise is just a quirk. I have heard several instances of folks having to replace cracked cylinder heads. Symptoms of heavy oil leaks.

I am not having much luck finding the compass. Does anybody have any more info on where to find this in the menus. RTFM is no help.

Thanks

webada

i think its normal, bmw does the same as well, for a few second... then again, we are only going by your description. if you are unsure of what a "normal" merc should sound like, go back to your dealer and try on a test drive c300 and if the sound is reproduced.

RLE

You replied: Yes, kinda. 3 to 5 seconds.

Ah ha. My C300 started doing this at about 4000 miles (now 5700) and my '01 C320 (M112 engine) did the same thing from about 1000 miles up until 65000 miles when I traded it.

It is the sound you usually hear after an oil change (by you) when the oil pump has drained and before it primes itself and you normally don't hear until the next oil change. If we DID have an oil pressure gauge, we would hear it go away as pressure comes up. But, my C320 did this 90% of the time when starting, hot or cold. And it never increased or decreased in volume.

There is a check valve on the output of the oil pump (I looked at the parts microfiche showing the pump) to prevent drainback after shutdown and I think my C320's was stuck open, so it took a few seconds to pressurize the system again.

Since I had never heard it until recently, I thought that I wouldn't hear THAT noise again, but here we go again.

I intend to discuss this with the MB service manager with a thought to replacing that check valve under warranty.

BTW, it's a rod knock and based on the 65K miles in the C320, I guess it's harmless, but annoying.

Germancar1

Most DOHC, multi-valve engines do this, some are noticeable some are not. Without hearing the sound we're all guessing here. Mercedes engines do tend to sound kinda gruff at time upon startup. It could be bad gas, or a number of things. You should let the dealer keep it overnight if it really bothers you that much.

M

oblu

I wish I could afford to leave my car at the dealer permanently.

I did bring it up with the dealer though. Answer: normal operation.

Doesn't really bother me, it's a lease and I only drive it to-from work now ... and if I have to wait for a tow on the way to work, I won't be heart broken ... just adding to the thread that mine sounds thrashy and "diesel-y" when it first starts.

But I'm also pretty sure I just have a cursed car anyway.

Les-10

I'm experiencing the exact noises in Tidewater VA with my 500 mile C300 Lux. Concerned there might be crank clearance issues. Unfortunately, I'm not leasing though.

Mercho82

I bought my c 350 2 weeks ago and stated noticing a rattle noise coming from the engine when I started it. Took it to the dealership and they said it was a sensor that was kind of losen. The fixed and now it seems ok.

Krytech

I also have been experiencing this sound when starting the engine. Seems to always happen when starting cold and even happens sometimes when starting it 'warm'. It doesn't happen when I shut the car and restart it after 5-20 minutes.

The sound only lasts for 2-5 seconds and sounds like bearings or a rattling sound.

theraj2

All the people on the east coast and/or west coast should go to one dealer... and flood them with the cars that are giving this problem... so that we can show them that were not crazy, and there really is a noise