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 > Diesel Discussion

LinkBack Thread Tools Display Modes
Old 01-27-2008, 12:22 PM
Registered User
Join Date: Jun 2007
Posts: 97
glow plugs 617

Do the glow plugs do anything after the car is started and the relay is off? I washed my engine today and accidentally knocked off the vacuum line on the IP that shuts down the engine, turned the key to shut the engine off but nothing turned the key back on and WOW the engine became almost silent, thinking maybe my glow plugs are bad?

Reply With Quote
Old 01-27-2008, 12:59 PM
Posts: n/a
Nope. They are only on between when you turn the key to when you use the starter.
Reply With Quote
Old 01-27-2008, 01:28 PM
Registered User
Join Date: Dec 2004
Location: Nashua, NH
Posts: 3,956
If I understand the post, you basically had a running engine and with it running turned the key off and back on again which would initiate a glow cycle on a running engine. On a cold engine, having the glow plugs heat while the engine is running will help complete combustion and reduce "clatter" which is probably what you thought was causing your engine to run more quietly. That is why the later engines feature "afterglow" which allows the plugs to continue to heat after the engine starts and cut down on emissions. So, yeah, they actually will do some good, at least on a cold engine after it is running but typically they are only "needed" to start the car. Even on the afterglow engines the GPs shut off after a minute or so. So contrary to your thinking there was something wrong, the fact that it quieted down proved the GPs are working fine.

I hope this answers your question.
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz
Reply With Quote
Old 01-27-2008, 06:35 PM
toomany MBZ's Avatar
Registered User
Join Date: Nov 2006
Location: central Va
Posts: 7,820
I'll agree with nhdoc, the key position should determine if the GP's engage, after a turn off and on.
I will assume you did this on a cold engine, also with nhdoc, normal. Try with a hot engine, better yet, reconnect the line.

83 SD

84 CD
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

All times are GMT -4. The time now is 12:06 AM.

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