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-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 11-27-2010, 11:07 AM
Registered User
 
Join Date: Apr 2005
Location: Pittsford, NY
Posts: 222
2002 E320 Door Lock issue in cold

Hi,
I have a E320 wagon with 67k miles that has a weird problem. The vacuum locks work fine when it is warm in the garage but work slowly or not at all in the the cold. This has caused the car to be robbed when a couple dorrs didn't lock correctly.
Any thoughts?
Steve

Reply With Quote
  #2  
Old 11-29-2010, 08:43 AM
Moderator
 
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
Most likely a leak in one of the vacuum diaphrams.
How long does the pump run?
__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator
Reply With Quote
  #3  
Old 11-29-2010, 10:05 PM
Registered User
 
Join Date: Jul 2008
Posts: 1,236
I agree. Either a leaky diaphragm is robbing vacuum from the system OR the vacuum pump is starting to get weak and doesn't like being cold.

Listening for the pump running is the next step either way. When healthy, you'll hear it kick on after locking the doors and a second or so after the doors all lock, the pump starts to slow down as the vacuum rises, then quickly stops as the negative pressure sensor engages.

If it's leaking, you'll likely hear the pump run for a bit longer than normal. Once we verify that, the next step would be to remove the vacuum line from the pump and cap (seal) the pump. Running the same lock-time test this time, the pump should run only very briefly and shut off quickly since its output is now sealed. If so, then you likely have a leaky diaphragm as mentioned before. If the pump still runs a long time, or sounds like its struggling, then its probably the pump motor, or the pressure sensor inside the pump is out of whack.
__________________
-tp


1990 300SE "Corinne"- 145k daily driver - street modified differential - PARTING OUT OR SELLING SOON - PORTLAND OR. AREA - PM ME FOR DETAILS
1988 560SEL "Gunther"- 190K passes anything except a gas station
1997 S420 - 265k just bought it with a rebuilt trans. Lovely condition
Reply With Quote
  #4  
Old 11-30-2010, 06:37 AM
Registered User
 
Join Date: Apr 2005
Location: Pittsford, NY
Posts: 222
I will check on this. I suspected a vacuum issue. Where are these diaphragms located?
Also where is the pump to listen to?
Thanks in advance.
Steve
Reply With Quote
  #5  
Old 11-30-2010, 08:14 AM
Moderator
 
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
The locking pump is under the back seat on the passenger side.
__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator
Reply With Quote
  #6  
Old 11-30-2010, 11:26 AM
Registered User
 
Join Date: Apr 2005
Location: Pittsford, NY
Posts: 222
Are the diaphragms part of the door locks themselves then? Would the leak be revealed with a pressurized smoke machine?
Thanks. Sorry I know so little about this issue.
Steve
Reply With Quote
  #7  
Old 12-13-2010, 06:17 AM
Registered User
 
Join Date: Apr 2005
Location: Pittsford, NY
Posts: 222
The pump runs for about 25 seconds initially then on subsequent locking and unlocking it is for about5 seconds. It doesn't sound weak.
Steve
Reply With Quote
  #8  
Old 12-19-2010, 09:16 PM
Registered User
 
Join Date: Apr 2005
Location: Pittsford, NY
Posts: 222
I think I found the problem

So here's what I found: No leaks detected with smoke machine. I did find the doors all maintained vacuum for 4 hours with a Mity-vac attached. The fuel door has its own line and could not hold a vacuum. It had no detectable leak with smoke machine. It appears the diaphragm in the lock unit to the fuel door must be bad.

I plugged the port on the vacuum pump until I can get a new one.
Steve

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 02:38 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page