frozenfish

Just got a brand new C300 in Canada 3 weeks ago, never owned an European car before, was driving entry-level Japanese cars like Civic for years. So to me European car engines, when comparing to Japanese cars, especially Mercedes, European engines must mean only quieter and smoother...

Which no doubt it does, or I should say, 99% of my 3 weeks ownership of C300, the engine of this baby is quieter and smoother...

But when driving in C-mode in the range between 60 to 100 km/h, then applying breaks to decrease the speed by 10 to 20 km/h, during this speed decreasing, sometimes I can hear engine higher-pitch 'whistling', it sounds more like it is doing down-shifting and RPM jumps by 100-200 RPM. I understand RPM jumps is normal when down-shifting, what my concern is, since the RPM is always less 2000 RPM during this speed decreasing, this high pitch whistling sound more like coming down from high RPM, although I don't know what this baby high RPM sound like yet... I don't mean the whistling is loud, but it is just as loud as my previous civic, and in a higher pitch sound, which is easily noticeable by passengers.

I will definitely bring this up in my next visit to the dealer, but before going, since I am new to Mercedes, just wanna see if this is normal or not... or maybe I am just too sensitive..

Benzagain

I am having this same issue from new only it is quite loud. It is doing this at 120, 70, 40 and 20 kmh on deceleration.
It's not normal so they are going to replace my transmission.

frozenfish

Just came back from Mercedes, their service manager took my car and drove around, he did also hear the whistling around 70km/h and other speed too during deceleration. He kept trying by switching gears in different speed, the whistling can still be heard.

He told me that this is definitely not normal, but he had no clue what this is, he said he will check with their bulletin or something and see if he can find any other info before sending my car back for further checking or repairing.

OMG, switching from Civic to Mercedes, I kinda expect everything, except gas milage, to be better/reliable.

I already found it ridiculous when C300's trunk fail to accept just one golf bag. I have to do the 'head-in' when trying to park my golf bag into the trunk, and it will occupy the entire trunk since it can only be placed diagonally. Sorry for crying out loud, but I can dump two golf bags to Civic without any problems without any efforts...

Not to mention I am getting 14.2 Liter/100km

Now, this whistling sound, gee, I don't know, being a first-timer of Mercedes, at this moment, I am sure Mercedes just lost one customer there.

I miss my Civic.

jrct9454

Point them in the direction of the transmission. That's the likely source of the problem, which is rare, but not unheard of.

As for your other complaints, if I lived in Canada, my first choice would have been the B-Class - more room, less fuel used.....

Benzagain

They should replace the transmission for you.
My dealer went through a series of tests as per the factory trying to eliminate the noise. They finally decided it was in the transfer case, a harmonic noise of some sort but rather than chase it they are replacing the whole unit. Don't settle for anything less on a new car imo.

frozenfish

Yes, as you guys pointed out, they had confirmed it is the transmission causing this whistling. They are ordering the new transmission from German since they said none can be found in Canada, which will take weeks for the new transmission to arrive.

I had no knowledges on how car engine works, but if I keep driving with this bad transmission before new transmission arrives, will it damage the engine or other parts? MB services told me it is totally fine to keep driving though.

Benzagain

You will be fine driving it, it is an harmonic noise like a turbine (torque converter maybe) not a grinding or metallic noise. Thats what mine sounds like anyway the dealer said it will be ok to drive and it's under warranty

frozenfish

Gee, after a week of investigation and fixing, the service said they still couldn't make the whistling sound go away....

This is totally unacceptable, I made a purchase of $50000+ vehicle, but they gave me a defect one. Then they try to fix it and HOPE it will work LIKE new, but found out it is a bigger problem than they thought. They also ruin this car when testing my car with high RPM which it is still in 'break-in' period.

I dont know about this, but I am gonna go ask for new car replacement or better yet, refund. I just had enough with this crap.

KuiDaCroat22

The two reasons why your disappointed with your MB and want to switch back to a civic is because you cant fit two gold bags in the trunk and you hear a whistle from your motor??? i can understand the whistle, its not normal, i hear it too, i think its the torque converter but dont quote me, but a honda over a mercedes.......shame on you

frozenfish

LOL, ya, I felt sorry for my own comments too, but for my own hard earn money, I will always choose a brand-new problem-free honda over a brand-new defect mercedes. Maybe I am too too picky, or maybe it is my bad luck, but could it be bad QC since I may not be the only one having this problem.

I know no production lines are perfect, but when you pay twice as much as civic, dont you kinda expect the chances of getting a defect one will be very low, or even none?

Sorry for having high expectation.

QQQ

You deserve high expectation alas MB is known as an unreliable brand.