shashivr4

After not driving my car (2013 E350 Wagon) for a few weeks on numerous occasions, I've noticed that on the initial start after the relatively long sit, a clunking noise is experienced along with the vehicle seeming like it doesn't want to move. I have to step on the gas pedal a little harder than I normally would have to simply to get it to move. Any ideas to what this could be? Sorry for the vague description...don't know how else to explain what is going on. Thanks.

Alex.currie44

Ok, I am running a 2011 version so pure guess.
Are you getting any indication the car is rising please wait?
My car has air suspension in the rear only and if it sits for several weeks I get this message and if I go too soon the suspension is flat.

shashivr4

No indication of that sort or any other. I always let the car run for 10 mins or so before pulling out...more than enough time for the rear air suspension to rise. Thanks though. Can you think of anything else?

Alex.currie44

Not off hand without more info.

Alex.currie44

Mileage on your car?

shashivr4

Just hit 3,000 miles.

PeterUbers

Parking brake status?

I suspect this will be a drivetrain issue... Trans, rear diff, or torque convertor

shashivr4

Parked in garage with park brake off.

The only other thing I can think off is that I washed the car before parking it for the few weeks. I noticed the rotors were orange (I assume rust)...could that have anything to do with it?

BTW, after the until start-up, the car behaved normally for the rest of the day.

PeterUbers

Brakes may be sticking ... But that's unlikely ... A few hard brakes and the rust will be gone

Alex.currie44

In my experience brake rotors will rust in hours after a wash if they don't get dried as they will over night in the rain or even snow. It is a fine layer and cleans up pretty quick on the first application of brakes.
Does it seem to come from one particular area of the car?
How long does it sit after your run after the initial start up? 2 hr? 6 hr? If it sits for 8 hr after you get rid of this noise does it come back after the 8 hrs?
My mind is wondering if the exhaust is loose when cold and it tightens up when it gets warmed up.
With 3000 mile why not take it to your dealer, get a loaner and leave with them to find it and fix it?

shashivr4

If I accidently engaged the parking brake when I last exited the car, would it automatically disengage by pressing on the gas pedal or would I have to manually disengage it by pulling the parking brake lever? Just asking because if it's the former, maybe I did accidently engage it. If it's the latter, I know I didn't accidently engage it because I definitely haven't manually disengaged it by pulling on the level (and there was no parking indicator on the dash today).

shashivr4

I just moved the car after 4.5 hours and everything is normal. Will try again tomm.

Will definitely take to the dealer...just want to make sure I'm not missing something first.

PeterUbers

Next startup try putting into sport mode before reversing

These cars have two reverse gears... See if it makes a difference

Re: parking brake ... A light should illuminate on dash if it's significantly depressed

PeterUbers

Try fully engaging parking brake and then disengaging anyway

shashivr4

Will do. However, I had backed in the garage so was actually going forward when this last happened today. It has happened going in reverse as well in the past though.

Alex.currie44

Two reverse gears? I have never heard of that. I always knew the "Comfort" start was a second gear start vs. first in "Sport" but did not realize there was a second reverse. Ratios are quite different too 3.4 vs 2.2. Interesting.
Not sure why one would want it. It is not as if we drag off the line going backwards!

PeterUbers

https://mbworld.org/forums/c-class-w203/293409-two-reverse-gears.html

Alex.currie44

Peter that is incredible. Thanks for all the info.
I would never consider a second reverse.
If you think about it I guess it has an application in snow just as the 2nd gear start is better in snow even with ESP.
The interesting fact is my W208 5 spd had it as did my 2003 W211 RWD and my W211 2009 wagon as well as it was 5 spd as well.
This is great info. Thanks again.

Sean1234

This would be my guess too

shashivr4

Is there a way to validate this hypothesis? If it only happens after a car wash (or any other event that gets the brakes wet and a subsequent long storage), is it safe to assume it's the brakes sticking?

Sean1234

What I would do is after you have stored for a long time when ready to drive the car do the following. Put car in drive and release parking brake, hit the gas lightly and move forward about half a wheel spin. Put the car back in park and get out to look at the rotors. If the brakes were sticking you should see marking on the rotor where the pads were stuck that will look different then the rest of the disk. Try to use the brake as little as possible when doing this since once the pad touch the disks a few times it will clean everything up

shashivr4

Thanks...that's a good idea. If it indeed is the brakes sticking, is there a way to prevent this?

Sean1234

Not much you can do, it happens with the moisture and stuff that builds up on the pads. Happens to me every once and an while.

Let us know next time you have a chance to test it out

Alex.currie44

I leave my car for 8 weeks at a time on occasions and always wash it before I put it away. I make a point of doing some hard braking maneuvers to dry the pads and rotors before I do.
I will see some light surface rust on the rotors when I get back that is gone after the first braking cycles as a rule.
If the testing reveals that it is brake related it suggests to me a caliper or calipers are not functioning correctly and the pads are being left under pressure against the rotor.
My wife's Matrix experienced that a few weeks back the difference being we could not get it to release under any conditions so the caliper was replaced. We did both fronts at the same time to be sure.

shashivr4

Drove the car today after 5 days of being parked. Car did not experience the loud knock as experienced last weekend. Car was not washed this time before the 5 day sit. Looks like it was the brakes. Will have to do a better job of drying the brakes after a good cleaning.