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 08-07-2001, 07:57 PM
Posts: n/a
"Economy" panel meter

On a 1989 300E, with 103 engine.... I get good position on the "Economy" gauge/meter on the dash.
But occasionally, the meter goes almost to full
RED position (for a mile or two) then jumps back
into the white zone.

What functions/parameters from the engine feed the
computation to operate this "Economy" meter/gauge?

Reply With Quote
Old 08-07-2001, 08:42 PM
J.HIDALGO's Avatar
Registered User
Join Date: Jul 1999
Location: Jax, FL
Posts: 1,785
Everytime you accelerate the economy needle should go to the red. Basically, as you "exercise" the engine, it produces more vacuum therefore, needle goes to the right/red...
If this happens during normal cruising speed (no sudden acceleration) then, that is another story.
'86 300E
Reply With Quote
Old 08-07-2001, 08:57 PM
Posts: n/a
It must be 'another story'. It happens after
a hard deceleration, then the needle 'jumps'
back to left/white and there is a noticible increase in power at same time. Yes, it happens
with no varying the accelerator, level ground.

Reply With Quote
Old 08-08-2001, 04:24 PM
sixto's Avatar
smoke gets in your eyes
Join Date: Jun 2000
Location: SF Bay Area
Posts: 20,123
Actually, the left/white zone is more vacuum and the right/red zone is less vacuum. The higher the vacuum while cruising, the higher the mpg.

I believe the economy gauge reads manifold vacuum directly, as in there's a vacuum hose that tees off the vacuum hose going to the transmission modulator.

A really uneducated guess would be that a solenoid or switching valve stays open too long then closes.

The manual talks about checking the vacuum hose for oil (that shouldn't be there). Could be that you have a leaking transmission modulator or something like that causing the faulty economy gauge readings.

91 300SE
Reply With Quote
Old 08-08-2001, 06:50 PM
J.HIDALGO's Avatar
Registered User
Join Date: Jul 1999
Location: Jax, FL
Posts: 1,785
Ooops! I had it backwards. The principle is the same, though. You probably have a vacuum leak somewhere...
Thanks Sixto!
'86 300E
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
Center console wood panel repair - W126 MikeTangas Detailing and Interior 12 07-27-2007 04:07 PM
Battery draining 300D SHARK1007 Diesel Discussion 3 01-09-2005 08:09 PM
W203 How to remove the panel under the center air nozzle eerola Tech Help 2 12-15-2004 07:40 PM
Tech Article -- Removing Door Panel on W115 Cazzzidy Diesel Discussion 6 10-26-2003 09:54 AM
Help: Rattle coming from interior panel or rear door renyf1 Tech Help 13 06-26-2002 11:43 AM

All times are GMT -4. The time now is 01:45 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