2014c300

Hello Everyone,

I am new to the forum and wanted to say hello.

I have been browsing this forum for a couple years now and finally decided to sign up.

I appreciate the wealth of information that all of you share on here, I am an avid researcher.

With that said, I think I have an issue that through many months of research I just can't put my finger on.

I am an enthusiast, I love sports cars. I used to own a 600 hp Camaro but sold it in 2011 to help pay for college tuition.

My soon to be wife and I leased our first C300's a couple of years ago and we are now on our second set of C300's.

We both got 2014's... Hers is Mars Red Sport Sedan and Mine is Polar White with the AMG Sport Package.

Here is my issue.

Her car handles way better than mine. Strange right? Tire pressures are set by the fuel door recommendation on both cars.. Hers 33 / 38 Mine 36 / 39

She is running 17" Continental Pro contacts - factory.. I am running Pirelli P Zero Nero's 18" Factory.

Her steering feels very tight and heavy like I think it should... My car on the other hand the steering is very light to the point when driving spiritedly it makes holding corners very difficult at higher speeds.

I have taken it back to the dealership to have checked out and OF COURSE i am told there is nothing wrong with my car. My Fiance and I have switched cars for a day or so and even she can tell the difference.

I have 20k miles on my car she has about 10k

To the best of my knowledge in 2014 both cars should come standard with speed sensitive steering correct?

My car the steering rarely seems to tighten up where her car the steering never ever loosens up or becomes lighter however you want to put it...

This problem I have been researching for months to no avail. Considering the extra money I spend on the AMG sport package I would have thought that my car should technically handle better than her car? Not the other way around.

Also I have noticed that her car the transmission is much much more responsive than mine.. It down shifts quickly and crisply every time. Where mine there is a delay in the shifts... it makes it terribly difficult trying to pass on the interstate without flooring the pedal overtime and having to time your pass just right, IE timing the delay in the downshift.

I have attempted the TCU RESET which the directions I Have found on here. It seems to do nothing. To be sure I was following the directions properly I took my laptop into my car with the website up.

Anyone else experiencing similar issues? I tried searching on here over the course of many months and just can not find someone with a similar issue that has a fix.

We both have the exact same car minus the wheels.. The cars should not feel this different in my opinion...

Thanks for any suggestions

Glad to finally be a member!

Carsy

I would check your front end alignment. It can make a big difference on how a car feels.

Take both cars in to your service dept & explain the problem.

Other than that I would swap cars !!

Good luck.

2014c300

Thank you for the reply.

We live in PA so I would guess it is possible that all the winter potholes may have tweaked the suspension / steering. The steering wheel is centered and the car tracks straight. But I can see how a slight tweak from a bump could change the dynamics but not bad enough to throw off the steering center or the straight tracking.

As far as the throttle response / down shift issue. I have no idea. I personally have no way to compare ECU / TCU software versions to see if hers happens to be newer.

I thought about having the ECU flashed by Eurocharged for $599 but the car is a lease and I am not sure I want to keep it in 2 years or not. Things could change, Raise? Etc and maybe I would be in the market for a C450 or even C63. The only issue with the C63 is we would need a 3rd car for me to drive to work during the winter, 4 matic is a must here.

I will schedule a 4 wheel alignment and report back.

2014c300

So I got my C300 back from the dealer. They did a 4 wheel alignment and road force balanced all 4 wheels. The service advisor said 1 of the tires would not come in to road force specs so they replaced it. Because I had previously replaced the same tire due to a nail they replaced it at no charge.

However, the car handles WORSE than it did when I dropped it off. There is still NO change in steering feel. At highway speed the steering is very loose. I believe what is happening is due to the very light steering feel at highway speeds it is introducing allot of oversteer.

I do not know how else to describe it. The car feels like a big old grandmas Buick , floaty and all over the place.

This is not how my fiancée car feels. Her steering is tight, solid and the entire car feels planted. It is fun to drive. And her car had the stock conti pro contacts with 17" rims.

I got a 2015 GLK 350 loaner while my car was in for service. I could feel the steering tighten up while in motion and loosen up when stopped at a red light. The GLK actually handles better by far than my car does. Which does not make any sense at all.

So I guess I will be taking my car back. The one thing I noticed that while driving both my front tires were at 41 psi and ambient temp was about 55 degrees today. Cold pressure is supposed to be 36 psi . The rear the left was at 41 and the right was at 43.

Did they not bother to check anything on my car or even test drive it... I am perplexed to say the least.

Just an update.

psaldanha

Hi!!

I may input some information regards your problem about steering in curves at high speeds. I have a C220 but in same sport package and everything else like yours. I had always fitted in my car just continental contisportcontac MO (mercedes approved). And the driving was like you said about yours wife´s car. A few weeks ago, i had to change to new tires. I bought and fitted at rear wheels Pirelli P Zero Nero, like your. The difference is that i have 18" wheels.

But the feel of driving is as you describe. It is different than before, worse! At high speed in curve i have to slow down a bit because the rear just dont grab to the floor.

So i think, like in my car, that the problem is the tires. Hope this helps you!!

I will keep the tires till get news (because now i cant return them), but will get only contisportcontact!!

2014c300

Thank you for the reply.

I have been wondering the same thing.

I have 18" Pirelli P Zero Nero tires

I have read about Micheline pilot sport A/S 3 , the many reviews I have read state that these are the best handling tires for our cars.

If u had the extra $1000 I would just order them, but I have 3 out of 4 brand new tires now because of one thing or other over this past year. Having to replace a tire here and there because of a flat. 1 was a nail and the others were bubbles in the side wall

2014c300

What ticks me off is this - my last c300 handled great non AMG package - conti pro contacts - and so did my fiancée 2013 Non AMG sport package.

We were done with our leases so I thought I would upgrade to the AMG sport package. I am a very spirited driver. I love canyon carving and that is the reason I chose a Sports Sedan. I love sports car handling.

Now, fast forward to 2014 C300 AMG sports package.. Car handles like garbage and everytime I take it to the dealer they tell me there's nothing wrong with it. I drive home and get behind the wheel of my woman's car and instantly see a night and day difference. The dealership is lying and hoping I go away. Why would they put garbage tires on a car with an upgraded package meant for better handling? Makes no sense at all. I paid MORE money for WORSE handling. 😕

psaldanha

A quick search in Google gave me some more info about these tires for Mercedes, with people complaining about the grip. Just check it:
https://mbworld.org/forums/c63-amg-w...different.html

Some say that there are Pirelli tire models specific for our cars, with Mercedes specifications, and for that, same tire model can be different as it is for a mercedes or not. So that could alter the grip handling.

I have the same tires like you. And Continental Contisportcontact. And i can see a difference between them in grip and handling. Way worse with Pirelli. Where i live Continental SportContact 5 255/35 R18 94Y MO is about 182 euro each tire. The Pirelli are 172 euro each tire. In the end, i believe it was a bad deal for me, so next time i will buy just continental or michelin.

About your problem, just get to the dealer if it is within warranty!! And good luck!!!

Oh, and by the way, check if your Pirelli are Mercedes original equipment (MO next to the model name like this: Pirelli P Zero 255/35 R18 MO. It must be in the tire!

Where i live costs between several tires brands are minimal.

2014c300

Your correct p zero Nero MO

2014c300

I read that in the past when researching this. That Mercedes has "special" tires manufactured just for them.

So I could purchase Pirelli P Zero Nero off tire rack.com but the MO would be missing and the tire could handle and wear differently. I didn't believe it because I wondered how could they get away with putting inferior tires on cars.

Maybe they do. I don't know. All I know is there are two 2014 C300's in our garage right now, and the red one with the 17" wheels and conti pro contacts handles great and mine with the perellis handles terribly. It seems to get worse every time I get it back from the dealer.

This is already the second dealer I have been too, the first sold me a a certified pre owned (my 2012 c300 ) with a right rear bent spindle. I had the car for 3000 miles, it had 5k on it when I bought it. 3k later it wore out a full set of conti pro contacts, they made me pay for it and insisted nothing was wrong with the car. I took it to Sears just for the heck of it they told me the right rear wheel was way out of spec. I took the print out and drove straight to the dealer I deal with now and they checked it and found what Sears found. I called corporate Mercedes and complained and complained. They quoted me $3500 to repair a certified pre owned that I only drive for 3k miles, never hit anything not even a pot hole.

That's how I got the car I have now. Corporate gave me a $2,000 credit towards a new one. So I got the 2014. Now I'm having all these problems with this one.

psaldanha

So, before getting the Pirelli i have order to get a fix to the wheels (they had a little bent), balance and align the direction of wheels ate rear (our cars align direction front and rear).

So my suggestion to you is, if you cant change tires, get some money or get the warranty to check wheels, balance and align direction.

But in my case, i positive sure that the problem is with the tires. Here is night so tomorrow morning will check in the tire for the MO (mercedes approval).

2014c300

I went out to the garage since it has been about 4 hours since I parked the car. I checked tire pressures with my brand new digital gauge. Front tires were at 40 psi still. Way to high, cold is supposed to be 36 psi. The backs were at 39 which is correct. So some of my issue on my drive home was the dealer over inflated my front tires by 5 psi each. I will recheck pressures in the morning and test drive again.

psaldanha

So today i check my tires, they are at rear Pirelli Pzero Nero GT. And they doesnt have the "MO", for mercedes. And checked too today tire pressure all around. But i didnt inflate so much like you did, 36 psi at rear and 35 psi at front. I dont like suspension so hard and maybe i will down a 1 psi or so.

But for conclusion, my best bet is for the problem are the tires that suck at grip. Today i get a drive in highway and in curves when before with conti there were no need to slow down and the car would grip very good, now wiht Pirelli grip is way worse and overseer occurs easily.

2014c300

Here is a recap: I picked my C300 up Friday. On the drive home the car was terrible to drive. The handling was over steering like crazy. Yes the steering was responsive, the car road smooth and responded very very quickly to steering inputs. TOO quickly. The steering wheel at highway speed felt way to light. You could easily find yourself in the other lane if you were not careful. It felt like the wheel had little to no resistance pushing back on you as you steer the wheel.
I have since driven 3 other Mercedes this week and all of them had tight steering at highway speed or even around town in sport mode. GLK 350 had noticeable tightness in the steering, my wife's C300 2014, and now the GLA 250 I have as a loaner without the sport package. I can feel the steering almost feels like it is pushing back on you as you drive and turn the wheel, an evident pressure to help you not oversteer.

That feeling in my car is not there at all. So I returned it to the dealer, I got my salesman involved we will see if it is another "there's nothing wrong with your car sir".

2014c300

Update: since we have a 2015 GLA 250 loaner, we decided to take it on our lunch date today. I drove to lunch, she is driving right now on the way home. I have to say we are both scratching our head. She instantly noticed how planted the GLA feels and how tight the steering feels.

So the question of the day is why does a GLA 250 non AMG sport package handle better than my C300 with AMG sport package? We both love this SUV it handles great it rides great.

I hope this time they fix my car and stop lying to me, telling me there's nothing wrong with it. Once again you can feel the speed sensing steering tighten up as vehicle speed increase and loosen as you come to a stop. In my C this does not happen.

I will update more after I hear back from the dealership. The dealers approach to my problem is this > "there's no code or check engine light on the dash so there's nothing wrong with the car, I must be to picky"

Hopefully this will help someone else in the future if and when my problem is resolved

2014c300

Got a call from my service advisor today. After having my car to the dealer several times I guess they FINALLY decided to drive it on the highway.

Now they finally agree with me that I am right. There is something wrong with the steering. The way my service advisor told me the mechanic described it was like driving a jet ski on a lake. Which is 100% accurate.

They have checked everything, they even put a set of 17" wheels on it and drove it like that, re checked the alignment again etc. Now they have a call in to Mercedes Benz to find out if they can re flash the software in the Steering control computer. They are leading me to believe they feel that the incorrect software was used for the steering from the factory. I always wondered why my finances c300 handled better than mine.. maybe this is why. Wrong software was used.. we will see when they finally figure out this problem.

Rodpwnz

I am happy to hear that you persistence paid off. I am hopeful that they will fix the issue and you can finally enjoy your car to it's fullest. I've dealt with the MB dealership for the past 5 years and it is incredibly hard to get them to acknowledge any issues. I''m looking forward to the update!

2014c300

Well the reason I am writing all of this stuff down is because I have found nothing online that resembles the issues I have been having.

I felt that I would put all of this out there with as much detail as possible in hopes to help a fellow Mercedes Benz Enthusiast some day.

I appreciate your reply.

psaldanha

Good luck with the dealer. Them tell us what was done and how is the drive compared to before.

tekfoc

doesn't the 2014 have the hydraulic power steering system.
if the op does which I'm sure it does the problem would more and likely be the speed proportional valve that control how loose and how tight the steering wheel gets according to speed.

2014c300

Ok, so I wondered why it did not make sense to me when my service adviser kept saying electric steering.

He called me back today and said he was sorry he was wrong. 2014's do not have electric steering and that the problem is my tires.. Pirelli P Zero neros... that is how they handle and if i want my car to handle like my wifes car i need to purchase different tires for $1000

2014c300

So here is a lesson to everyone!

If you plan on purchasing a Mercedes Benz DO NOT accept the vehicle with Pirelli P Zero Nero's on it.. Tell them to take them off or you will not purchase the vehicle. I have already replaced 3 of theses tires already. If i had known this then i would have not used the same tires.. Now they tell me after I have almost purchased an entire second set of Pirellis.. what a bunch of Dik heads

2014c300

I guess the plan is we are going to put the Micheline Pilot Sport A/S 3's on the rims and see if that changes it. It appears they may be discounting them heavily for me since i have had so many issues with my current tires. We will see.

psaldanha

Nice you sorted out.
For now i will keep the Pirelli Pzero Nero GT at rear that i bought because i cant change them now...

2014c300

Ok... update

My car has been back to the dealer 2x since I last posted. I am sure they are getting fed up with me however I am getting fed up that they are telling me that there is nothing wrong with my car when my wife and I both agree that their is.

The dealership got another car identical to mine back from lease. Same wheels but the rims have conti pro contact tires on it rather than P Zero Nero's...

1. They let me drive that car, and it felt great.. the way I think its supposed to. The same way my wifes car feels on the 17's.. the steering was tight and the car felt planted

2. They swapped the wheels from that car with the pro contacts and put those wheels on my car and let me drive it tonight with the other wheels and pro contacts on it..

Did not notice a darn bit of difference car felt exactly the same. So that rules out tires like they were trying to tell me it was.. So it is not tires.

I am still stuck on shocks.

Last year in a construction zone right before winter.. i hit a bump at about 55mph... the sign was way to close to the actual bump so you never had time to slow down.. it bent 3 of my AMG wheels and put a bubble in my front right P Zero Nero... The dealership repair the 3 wheels and replaced my tire. Did a 4 wheel alignment and road force balanced all 4 wheels.

The car has never been right since... Also the car hit the bump so hard the safety restraint system in the drivers and passengers headrests deployed... I looked up a video on you tube and put the headrests back together myself.

Now with everything that has gone on... I personally feel that something is tweaked in my suspension.. The dealer keeps telling me there is nothing wrong with it but I have excessive body roll in the entire car.. the steering feels very light or lose and if you move the car back and forth with the steering wheel the body roll at highway speed is very evident compared to all of the other C300's i have driven... but they still say that there is nothing wrong with it.

I am about fed up and frustrated as I can get.. The car is not fixed... It is not handling properly.. I personally feel that when I hit that bump it tweaked the shocks in the front and rear due to the instant contraction of the shock into the cylinder...

The dealership has no way that I know of of actually testing the shock... so all they are doing is telling me that it is ok without actually knowing for a fact that it is ok.. without a shock dyno the only way that I know of to properly test the shocks would be to take them out and check them against new ones out of the box....

Keep in mind these shocks only have 22k miles on them so the same symptoms of a worn out shock would not apply... I believing the dampening rate and valving is messed up so the shocks are not rebounding correctly...

If you google. how to check if i have bad shocks one of the symptoms is excessive body roll which I have... however the car does not bounce or nose dive like worn out shocks would.. I think what has happened is that the shocks have lost their stiffness but are not showing the symptoms of excessive wear.

I am about to go to sears and tell them to replace them and be done with it.. not sure what else to do... this is the 5th time the dealer has had my car and they still have it..