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

LinkBack Thread Tools Display Modes
Old 01-12-2001, 10:19 PM
Posts: n/a

I have a 1995 C280 which was recently serviced. Before bringing it in, there was a recoccuring noise in the area of the right - rear passenger door or coming right from behind. My mechanic said it was the fuel line or pump and said he fixed and the noise was normal (its still there) and I don't think its normal, and passengers in the rear complain about it because it sound like a pump filling up over and over again. Just a little info about it - the car started doing it about 75,000 miles, and so did my 94 C220 and it still does it. It will make the noise in Park, Drive, Reverse for about 5-10 mintues, and after driving it eventaully stops. also, when the battery is turned on only, it will make the noise. Please help with this issue - is something that can be fixed or is the aging of the car.

Reply With Quote
Old 01-13-2001, 08:00 AM
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
Sounds like the central locking pump is running. MB uses this pump for many duties, including manifold assist. IF there is a vacuum leak in A/C system then this pump will help supply vacuum so that ducts can open & close. The pump is in the trunk on the rt side behind the carpet. LIsten & see if its running. The reason it shuts off after 5-10 minutes is thermal overload protection. NOT good.
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
Old 10-31-2003, 01:20 PM
est est is offline
Registered User
Join Date: Dec 2002
Location: Tallinn, Estonia
Posts: 16
I have the problem in the same area. But a little bit more serious.
One c280 came to me with complaint that central locking isnt working. Pump motor burned- so i replaced it with a different one (motor not the whole PSE). Everything was working fine ntil car left garage. The vacuum pump started working constantly when the throttle was apllied. Here is the interesting part - the more throttle- the faster pump runs. I checked the line from the pump up to vacuum valve block for leaks- none found. I unplugged all the lines from the vac valve block and tested them- everythig fine.
So i concluded that the problem is in vacuum valve block- got the new one- still no change. I plugged the vacuum line from the intake manifold- no problem. What components are there between the vacuum valve block and the pump vacuum line ?
Should there be a one way valve somewhere? As far as i understand the vacuum valve block should not let the vacuum pump to suck the air from manifold, but in this case it does.
Or is the problem in the PSE? It shuts down when there is sufficient vacuum in the line, so may it be going nuts?
Central lock is workig fine.
So, shortly speaking there is a twoway connection between the PSE and the manifold.

Thanks for bearing with me, i am out of ideas and cant find any info on this MVA-SRU system.
Reply With Quote
Old 11-02-2003, 02:34 AM
Registered User
Join Date: Jun 2002
Location: Melbourne, Australia
Posts: 80
Talking Buzzing noises in the boot

I had this same noise in my boot (1994 C180 Euro) last year . It sounded like a buzzing sound every 1 or 2 seconds for about 15 minutes from start of every journey. The sound goes away after a while. It comes back after I restart the car for another journey. Very irritating sound for rear passengers. My indie took down the whole dash and found 2 airflow actuators had torn rubber diaphrams which therefore couldn't hold vacuum. These were replaced and the noise stopped except for just 1 buzz when the engine is switched on. The main problem the leak caused was the rearheadrests refused to come down when the button was depressed with the engine running. Not enough vacuum. This year, recently, my centre a/c vents are working off and on and I think there are more problems with the vacuum system. Can anyone help out on this? Most of the time no or very little comes out from the centre vents, sometimes it works properly for a few kilos then stops blowing completely. The side vents work properly all the time.
Reply With Quote
Old 11-04-2003, 10:24 AM
est est is offline
Registered User
Join Date: Dec 2002
Location: Tallinn, Estonia
Posts: 16
The problem in your case probabliy is either in the nozzle's vacuum actuator or in the vacuum line to it. You could get to the nozzle and check if the diaphragm is ok. If it is fine then it is kinda hard to find the leak in the line
Reply With Quote


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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Noise coming from rear hubs aldedmon Tech Help 4 08-25-2004 09:49 AM
Autocrossing a 400E and 300TE 400ERACER Performance Paddock 9 06-05-2004 02:50 PM
W210 E class buzzing noise ckNSX Tech Help 3 11-28-2002 12:50 PM
Is loud cabin from road noise? gselzler Tech Help 10 11-16-2002 12:09 AM
Hydraulic lifter noise or injector noise? jrd Tech Help 6 01-06-2000 05:19 AM

All times are GMT -4. The time now is 05:21 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, 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