Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 12-02-2002, 05:46 PM
Registered User
 
Join Date: Apr 2002
Location: Long Island, NY
Posts: 131
Angry Knocking/Rapping Noise

Please help. I am trying to diagnose a sharp knocking or rapping noise coming from the left rear of my '88 420SEL. It happens on acceleration and goes away when I ease off of the gas.

After poking around under the car, I thought the culprit was the
sway bar links, the left side felt loose and clicked when manipulated. So I replaced both sides. Noise went away for 2 days, then came back. Any suggestions?

Thanks,
Mike
__________________
Thanks,
Mike

'83 300D
'87 Volvo DL Wagon
'88 420SEL (SOLD)
'98 Toyota Camry SE V6
'96 Ford Brono XLT
'94 Mercury Villager
'46 Willy's CJ2A
'40 Packard 110 4DSD

"Just another squirrel, trying to get a nut"
Reply With Quote
  #2  
Old 12-02-2002, 10:45 PM
Registered User
 
Join Date: Jul 2000
Posts: 638
knocking at rear on acceleration

could it be exhaust pipe hitting? Check all the hangers to make sure they are OK.
Reply With Quote
  #3  
Old 12-02-2002, 11:51 PM
Registered User
 
Join Date: Apr 2002
Location: Long Island, NY
Posts: 131
Exhaust hangers look good. The bottom-out bumpers are intact.
I tried to recreate the noise by shaking the exhaust, nothing.

In other posts that the symptoms sound close, it has been
suggested that it might be the axle halfs.
Can anyone tell me how to check them without using "replace & see" technique?

Thanks again!

Mike
__________________
Thanks,
Mike

'83 300D
'87 Volvo DL Wagon
'88 420SEL (SOLD)
'98 Toyota Camry SE V6
'96 Ford Brono XLT
'94 Mercury Villager
'46 Willy's CJ2A
'40 Packard 110 4DSD

"Just another squirrel, trying to get a nut"
Reply With Quote
  #4  
Old 12-04-2002, 02:59 AM
afmcorp's Avatar
Registered User
 
Join Date: Jan 2002
Location: NW Indiana LaPorte
Posts: 571
hi

you didn't mention how the rapping sounded. does it change with the rpm. does it do it only while moving or does it sound off at a stand still? does it sound off on acceleration or deceleration. have you ruled out the engine compartment?

i am replacing a camshaft this week on my 420sel. i would describe that as a sharp rapping also. mine lunched a rocker arm wore down so bad i have to replace the camshaft as well.

with a bit more description we (the forum) may just figure this one out.
__________________
Thanks Much!
Craig

1972 350sl Red/Blk 117k
1988 420sel charcoal/Blk 140k
1987 420sel gold/tan 128k
See My Cars at:http://mysite.verizon.net/res0aytj/index.html

Pound it to fit then Paint it to match!

There is only First Place and Varying degrees of last!

Old age and deceit will overcome Youth and Enthusiasm every time!

Putting the square peg in the round hole is not hard... IF you do it fast enough!

Old enough to know better but stupid enough to do it anyway!
Reply With Quote
  #5  
Old 12-06-2002, 05:58 PM
Registered User
 
Join Date: Apr 2002
Location: Long Island, NY
Posts: 131
Hi Craig,

This is definately from the rear.
Only on accelleration in drive. More rapid and louder earlier under accel. and diminishes as it gets up to speed and I back off the throttle.

Does not happen when parked and revving engine.
I was able to reproduce it slightly by standing on the brake and revving the engine while in drive. I had a friend outside the car confirm that it was from the rear drivers side.


Thanks,
Mike
__________________
Thanks,
Mike

'83 300D
'87 Volvo DL Wagon
'88 420SEL (SOLD)
'98 Toyota Camry SE V6
'96 Ford Brono XLT
'94 Mercury Villager
'46 Willy's CJ2A
'40 Packard 110 4DSD

"Just another squirrel, trying to get a nut"
Reply With Quote
  #6  
Old 12-07-2002, 11:33 AM
dpetryk's Avatar
Electrons can do anything
 
Join Date: Sep 2001
Location: Houston, Texas
Posts: 1,071
Mike I am having the same problem on my 300E. I suspect the axle joints especially the outboard one on the drivers side to be on its last leg. I only have the noise under acceleration and in right turns only. Back off and i t goes away. Its getting worse so its just a matter of time before the truth is known. If its not the axle then it must be the wheel bearing. But I hope it is something less expensive.
__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k
Reply With Quote
  #7  
Old 12-09-2002, 12:47 PM
Registered User
 
Join Date: Apr 2002
Location: Long Island, NY
Posts: 131
Dave,

I think you are probably right about the axle joints.
Any idea how to test them? Can I possibly inject some grease into the joint to see if it stops the noise (temporarily)?

Thanks,
Mike
__________________
Thanks,
Mike

'83 300D
'87 Volvo DL Wagon
'88 420SEL (SOLD)
'98 Toyota Camry SE V6
'96 Ford Brono XLT
'94 Mercury Villager
'46 Willy's CJ2A
'40 Packard 110 4DSD

"Just another squirrel, trying to get a nut"
Reply With Quote
  #8  
Old 12-09-2002, 01:09 PM
dpetryk's Avatar
Electrons can do anything
 
Join Date: Sep 2001
Location: Houston, Texas
Posts: 1,071
I have never been into a MB type. I understand that they use an oil rather than grease like is typical of CV joints. I am in uncharted waters here. Hopefully someone else with more experience or knowledge will chime in. I doubt that injecting grease will cure them. I suspect that they are worn out. Not sure how to test them either.
__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k
Reply With Quote
  #9  
Old 12-09-2002, 01:35 PM
Registered User
 
Join Date: Apr 2002
Location: Long Island, NY
Posts: 131
Dave,

I'm thinking that injecting grease into the joint would simply confirm the diagnosis, not cure it.
How difficult a job is it to replace the shafts? Any tips, anyone?

Thanks,

Mike
__________________
Thanks,
Mike

'83 300D
'87 Volvo DL Wagon
'88 420SEL (SOLD)
'98 Toyota Camry SE V6
'96 Ford Brono XLT
'94 Mercury Villager
'46 Willy's CJ2A
'40 Packard 110 4DSD

"Just another squirrel, trying to get a nut"
Reply With Quote
  #10  
Old 12-09-2002, 06:55 PM
dpetryk's Avatar
Electrons can do anything
 
Join Date: Sep 2001
Location: Houston, Texas
Posts: 1,071
Mike, explain how grease would confirm the diagonsis. I have the CD rom which details the proceedure. Looks like one might need special tools to get the job done. Certainly will if the wheel bearing is to be replaced.
__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k
Reply With Quote
  #11  
Old 12-09-2002, 06:58 PM
engatwork's Avatar
busy
 
Join Date: May 2000
Location: Soperton, Ga. USA
Posts: 11,776
Changing them on the 300D was by far one of the easiest diyer type jobs I have done. I'm sure ya'll model is just as easy.
__________________
Jim
Reply With Quote
  #12  
Old 12-18-2002, 04:27 PM
Registered User
 
Join Date: Apr 2002
Location: Long Island, NY
Posts: 131
Sorry for the delay in getting back to you Dave. It's tough when your employer keeps you busy at work, and the wife keeps you busy at home!

I am working on the (probably wrong) assumption that the joint is making noise do to a lack of lubrication.

My thinking is that by injecting grease into the joint, the new grease would quiet it down temporarily (since it would no longer be sealed).

Regards,
Mike
__________________
Thanks,
Mike

'83 300D
'87 Volvo DL Wagon
'88 420SEL (SOLD)
'98 Toyota Camry SE V6
'96 Ford Brono XLT
'94 Mercury Villager
'46 Willy's CJ2A
'40 Packard 110 4DSD

"Just another squirrel, trying to get a nut"
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 12:40 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page