Thanks, Jeff.
Today we test drove two B-Class EDs, back to back, a 2014 and the 2015 we are considering buying.
There appear to be a few noises at play, some present only on the 2015 car we are considering.
Road Noise - this seems to be present on all of the B's, so I'll consider this "normal"?
This noise is likely tires, possibly wheel bearings, suspension, or something like that.
In every B-Class I've been in (4 seperate cars now, two 14's, and two 15's) the road noise is louder than it is in my Ford C-Max Energi, by a
wide margin. Today I verified this. I thought the rear cargo cover might help dampen the noise, but it didn't do too much of anything, so I think the tires equipped on the B's must just be louder than what I have on my C-Max Energi (which is equipped with Michelin ENERGY SAVER AS 225/50R17 70895 94V BS). Perhaps because the B's often have run-flats is my best guess for the added noise?
Air Conditioner Noise - maybe fan noise? - Without a doubt the AC system in this car is unique. The system noise seems to ramp up and down - it sort of sounds like when you're on an airplane preparing for takeoff. This noise comes and goes depending on speed, and is even somewhat present at idle. If you drive say up to 40MPH, then come to a stop, after you are stationary, you can hear a somewhat loud humming noise, that then gradually dissipates (like spooling down).
There appears to be an evaporator fan under the hood that adjusts speed when the AC is turned on. When the car is sitting idle, with AC turned off, the fan runs at a very low speed (even though it's 100+ outside). Once you engage the AC, the fan I see in the front, under the hood, likely for the condenser, adjusts speed, and spins much faster, which makes complete sense, seems like a good design. I cannot confirm this fan is the source of the noise though. Maybe a fan mount or something causes vibrations and noise? Maybe the compressor itself is the cause of noise. Unknown currently.
Air Conditioner Noise / Rumble
Even at park, when you turn the AC on, you can actually feel the car vibrate in the front passenger footwell, along with a rumbling noise. It sounds and feels like an ICE car that's sputtering somewhat - it's not exactly smooth. My passenger in the rear said they could slightly feel a rumble (at park) through the floor as well, and they too could hear the noise very clearly - they at least can confirm I'm not crazy.
The backstory on the car
This car I am considering is at CarMax. I had the car transferred in. I have received a full refund for the transfer fee already (wahoo!).
The car is a 2015, with Premium Package, Multimedia Package, Heated Seats, BLIS, South Seas Blue on outside, beige on inside.
25K miles, $16K. Factory warranty remains (Start date of factory warranty: 9/26/2015), 90-Day CarMax bumper-to-bumper warranty also included.
Normally I'd run from this car - too many noise issues that concern me. My dilemma is, finding a car for this price, with these options, in this color, has proven a challenge. Apparently in 2015, not too many B's got heated seats - strange, almost all of the 14's I find have it. Must have been how things were optioned.
Being that this is a CarMax car, and I'd be paying cash for it, I have 7 days to return it, no questions asked. I do not have the option of bringing the car to a Mercedes dealer (myself) prior to purchase, but I do have a 7-day period to do so, risk free, and return if I want (but not hassle free I'm sure).
Where I left things
CarMax will attempt to repair the car. I brought up 4 concerns - 3 of them are easy things I'm sure they can fix, the 4th is the AC noise. I'm under no obligation to buy. CarMax has a service ticket to repair the car. The car is held (no one else can buy it), so I have a chance to review the repairs and see if I'm satisfied prior to buying. I'm not confident they will know how to address the noise issues, and I'm unsure even if they sent the car to the Mercedes Dealer (which they often do I'm told), if the dealer would resolve this concern on the first go.
Where I stand
I'm patient. I'll wait to see if they are able to resolve, if so, I
may consider the car. Meanwhile, I will continue hunting. One option I must consider is MaxCare (CarMax's Extended Warranty offering) - I'm not one to pay for a warranty, but a close friend of mine has
extensively used MaxCare with extreme success over the years. On one of his 3 MaxCare cars, he had over 26K of repairs to his Audi's - yeah, they break a lot
, and we're both quite particular. I recall an "ashtray assembly" the Audi dealer replaced using the MaxCare warranty for over $800! Insane.
With MaxCare I'd have essentially bumper-to-bumper 60-month coverage (that would last me into June of 2024 - up to 75K miles, which is fine for me as I don't drive that many miles). The cost for the ESP is a fair ~2K... Not sure I want to spend that extra yet, but, considering it - especially with the unknowns surrounding the drive unit, etc. And all this supposes I actually want to buy
this car. I'll report back.
Thanks again!