300M 'Scraping' sound after 20+ miles

I have a 2003 300M with 25,000 miles on it. Apart from engine problems
when new, the only service has been regular oil changes.

A few weeks ago after a 80 mile drive on the NJ Garden State Parkway I
heard a 'scraping' or 'swooshing' sound as I departed from the toll
booth. Applying the brakes did not seem to change the sound which, at
first, I thought was an aircraft overhead. The sound then disappeared
and does not recur on short local drives. The sound appears to be
coming from the right rear of the car, but I am not 100% certain of
this.

A week later, the same thing after a 25 mile drive. This time I
thought applying the brakes made it slightly worse, but again it
disappeared. In all it has now happened four times, so I am taking it
into a Chrysler dealer next week. The brake pads all look to have
plenty of life left in them.

I am asking if anyone can give me their thoughts on possible causes.
It only seems to occur after running for 20 miles plus continuously.

I have never been impressed with Chrysler service, after having used
two so called Five Star Dealers, so any heads up would be appreciated.

I still have the original Chrysler 7 year warranty that came with the
car, although I believe their are a couple of local service garages
(not affiliated with a car brand0 that friends have recommended, who
say they will honor the warranty.

 

Nothing too specific to offer other than brakes and wheel bearing come
to mind.

You are aware that there are separate brake shoes for the parking brake
(rear rotors are a combination rotor - for main brakes - and drum - for
parking brakes). Did anyone pull the rotor/drum and check for parking
brake drum/shoe issues (possibly some rust noise?).

BTW - come on over to the 300M Club: http://300mclub.org/index.php

Forums:
http://300mclub.org/forums/index.php?sid=426876de8fc01e7e267dc347d2afee34

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

There is a metal tab from the brake shield that may be hitting on the rotor.
It would give you a very loud squeal noise and could come and go as you hit
the brakes. You will need to slide under the vehicle or raise it to see if
this is the problem.
Bill Im surprised you didn't point that out!!

Glenn Beasley
Chrysler Tech

 

sounds like you have a failing wheel bearing
most all who in my shop say the same thing it sounds like a aircraft

 

Hi...

I had this happen 10 years or so ago with a Buick, so an experiment
for the OP that might prove useful if I may?

I found that a long gentle curve (about the degree of turn that
you'd find at an overpass entry/exit ramp would cause it to be
much more noticeable in one direction; and disappear in the other.

Perhaps the OP might try something similar after it's warmed up
and acting up in an empty parking lot or something. Perhaps with
all the windows open, at a speed where he can hear the squeal well
without too much wind noise?

Mind you, mine was a front wheel, so that might have made a
difference.

Take care.

Ken

 

I didn't because he seems to think it's from the rear, plus most people
would describe the sound from the bent rotor shield as a "squeal" rather
than a "swooshing" sound. But certainly something he should check for
(noises often fool people as to which part of the car they're coming from).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Many thanks to all the responders for your suggestions and help.

I think it has always happened after a slight right hand curve. As was
also mentioned, I agree that I could be wrong that it is definitely
the right rear wheel, rather than the front right.

As it looks like bearings are covered under the Maximum Care extended
warranty, I'll probably take it back to my Chrysler. However, if I am
not out of line asking, can anyone recommend a Chrysler dealer in the
Ocean/Monmouth vicinity (Lakewood NJ}.

 

Just a quick follow up.

The Dealer had it yesterday, took it on a run and couldn't hear any
noise. They checked brakes and bearings and said there were no
problems.

The only thing found was a plastic piece at the front of the car that
they riveted as it was loose. Couldn't say if that could be the
problem.

I'll just have to listen again after a reasonable run.

 

Ahh! The air dam. That was probably it. It is very common for those
to come loose - and when they do, they can rub on the road, tires, and
other stuff, adn make noises as you described.

Thanks for the followup post.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')