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

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 09-28-2009, 11:52 AM
Registered User
 
Join Date: May 2009
Location: NY City -Queens
Posts: 34
NAILING

I have seen posts that mention NAILING. What exactly is nailing and how does it sound. My 240D engine sounds like a diesel. How do I know if it is NAILING.
Anthony

Reply With Quote
  #2  
Old 09-28-2009, 12:04 PM
Biodiesel300TD's Avatar
|3iodiesel300T|)
 
Join Date: Dec 2004
Location: Albany, OR
Posts: 4,845
Nailing is caused by worn injectors. When injectors get worn out they can leak fuel even when not at pop pressure. This causes excess fuel in the cylinder which creates hard combustion which is the noise you hear. It's an extra loud sharp clacking noise.
__________________
Andrew
'04 Jetta TDI Wagon
'82 300TD ~ Winnie ~ Sold
'77 300D ~ Sold
Reply With Quote
  #3  
Old 09-28-2009, 12:13 PM
Registered User
 
Join Date: Jan 2002
Posts: 18,350
It sounds like someone driving a spike into a piece of oak, hence nailing.
__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13
Reply With Quote
  #4  
Old 09-28-2009, 12:22 PM
tbomachines's Avatar
ಠ_ಠ
 
Join Date: Mar 2009
Location: Philadelphia
Posts: 7,034
Quote:
Originally Posted by kerry View Post
It sounds like someone driving a spike into a piece of oak, hence nailing.
I would say it sounds more metal-on-metal hammering but I guess thats splitting hairs
__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth
Reply With Quote
  #5  
Old 09-28-2009, 12:28 PM
71inka02
 
Join Date: Oct 2008
Location: Greensboro, NC
Posts: 286
When I had the problem on one of my diesel MB cars of past -- It was almost like a "spark knock" you would get in a gasser...Replaced the injectors and noise went away...
__________________
71Inka02

62 W121 190DB - Original CA/AZ Car - Excellent Example
99 E300 Turbo Diesel - 362,000...Awesome Daily Driver
01 E320 Wagon - 297,xxx (wife's work car)
01 E320 Wagon - 131,000
02 Land Rover Disco SE- 110,000
87 BMW 325is (E30) Full Restore - Son's
06 Mini Cooper 'S' - Son's
87 Toyota FJ60 Land Cruiser - Showroom Condition - 152,000

84 300D - 142,xxx :cool - "Sold"
83 300D-"Sold" - 211,456
85 300SD-"Sold" - 213,789
Reply With Quote
  #6  
Old 09-28-2009, 12:43 PM
Registered User
 
Join Date: Jan 2002
Posts: 18,350
Quote:
Originally Posted by tbomachines View Post
I would say it sounds more metal-on-metal hammering but I guess thats splitting hairs
Not to split hairs, but the hammer would be striking a metal spike.
__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13
Reply With Quote
  #7  
Old 09-28-2009, 01:12 PM
Registered Hack
 
Join Date: Mar 2008
Posts: 4,642
nailing is a detonation at any undesirable time during the stroke.

like an explosion that is not absorbed by the movement of the piston ()think of catching an egg from an overhand pass()
__________________

Reply With Quote
  #8  
Old 09-28-2009, 01:28 PM
Crazy_Nate's Avatar
Registered User
 
Join Date: Jan 2008
Location: Hampton Roads
Posts: 567
Quote:
Originally Posted by jt20 View Post
nailing is a detonation at any undesirable time during the stroke.

like an explosion that is not absorbed by the movement of the piston ()think of catching an egg from an overhand pass()
If that's the case, the injectors may not be the only possible culprit, right? Incorrect IP timing could cause undesirable results. Would this sound like nailing?
__________________
1982 240D, sold 9/17/2008
1987 300D Turbo
W124.133 - 603.960, 722.317 - Smoke Silver Metallic / Medium Red (702/177), acquired 8/15/2009
262,715 and counting
Reply With Quote
  #9  
Old 09-28-2009, 01:48 PM
Registered Hack
 
Join Date: Mar 2008
Posts: 4,642
there are certainly more culprits.

IP timing could do it as well.
__________________

Reply With Quote
  #10  
Old 09-28-2009, 01:49 PM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 43,173
Fue Injection Pump Timing can case Nailing, worn Injectors as well as air in your fuel system.

If you get your Engine started on a cold day without using the Glow Plugs you will hear the Nailing sound until the combustion chambers warm up enough for the Fuel to burn properly.
__________________
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
  #11  
Old 09-28-2009, 01:55 PM
Registered User
 
Join Date: Jan 2002
Posts: 18,350
Quote:
Originally Posted by Diesel911 View Post
If you get your Engine started on a cold day without using the Glow Plugs you will hear the Nailing sound until the combustion chambers warm up enough for the Fuel to burn properly.
My Mitsubishi Fuso glowplugs only activate below about 35 degrees. When I start it at 40 degrees it nails like crazy until it warms up.
__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13
Reply With Quote
  #12  
Old 09-28-2009, 02:48 PM
Oldwolf's Avatar
124.128/602.962/722.418
 
Join Date: Apr 2009
Location: Raleigh, NC
Posts: 1,017
Is Nailing to be expected in a cold engine? Mine nails a little during warm up and is gone when the engine reaches 80C.
__________________
1993 W124 300D 2.5L Turbo, OM602.962
2000 Chevrolet Cavalier, 2.4L DOHC
2002 Ford Explorer, 4.0L SOHC
2005 Toyota Prius, 1.5L

http://www.fuelly.com/sig-us/40601.png

Last edited by Oldwolf; 09-28-2009 at 09:21 PM.
Reply With Quote
  #13  
Old 09-28-2009, 03:55 PM
tbomachines's Avatar
ಠ_ಠ
 
Join Date: Mar 2009
Location: Philadelphia
Posts: 7,034
Quote:
Originally Posted by Oldwolf View Post
Is Nailing to be expected in a cold engine? Mine nails a little during warm up and is gone the engine reaches 80C.
I wouldn't necessarily say expected, but certainly a common experience among higher-mile cars with questionable injectors so don't be too freaked out.
__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth
Reply With Quote
  #14  
Old 09-28-2009, 04:14 PM
Dionysius
 
Join Date: Jan 2006
Location: Seattle WA
Posts: 261
Lightbulb The Genesis of 'Nailing'

All of the following are from my personal experiences so please challenge me as you see fit. Some of this has not been written about or at least I have not come across it.

'Nailing' has many causes. The sound is produced from a secondary combustion event which is temporally and/or spatially separated (usually retarded in time) from the main explosion. Generally it can be caused by an Injector with an uneven spray pattern or with an imperfectly atomized trickle flow.

In a normal situation a coherent explosion with a smooth well defined flame profile occurs at the expected time. Nailing represents a perturbation to this process caused by one or more of the following:
  • Assymetrical injector spray pattern
  • Carbon build up in the pre-chamber and other explosion space
  • Mechanical distortion or damage to the explosion space
  • Damaged or distorted atomizer
  • Air ingress into the hi pressure fuel lines (Many causes give rise to this including air ingress into the lo pressure side being referred into the hi pressure circuit sometimes but not always by the IP)
  • Incorrect IP timing relative to crankshaft/cam timing
  • Mal-adjusted valves
  • Very low temperature in the explosion space caused by GP issues, low ambient conditions, etc.
  • Low compression

I did this from my head so I may have missed some but you get the point.

As was pointed out it does acoustically sound somewhat like what is referred to as 'pinking' or 'pinging' or 'pre-ignition' where low octane gasoline is used in a hi-compression gasoline engine. It is a different phenomenon however in a Diesel engine since it is usually a retarded timing event that gives rise to 'Nailing'.

Is it bad for an engine?? Let us agree that it is not good but since these engines are extraordinarily robust it does no harm as long as it does not persist all through the operation. After warm up most nailing will disappear. 'Pre-ignition' in a gasoline engine however is very destructive. I have seen a piston with what looked like a bullet hole through its face from the effect.

Does it negatively affect MPG?? Of course the answer is yes. Energy is being used in an undesired manner that is not contributing to the desired power flow.
__________________
Dionysius
Reply With Quote
  #15  
Old 09-28-2009, 06:20 PM
sasquatchgeoff's Avatar
Cascade Foothill Lurker
 
Join Date: May 2007
Location: Portland, OR
Posts: 561
I would add mal-adjusted injectors to Dion's very complete list as well. Differing pop pressure between cylinders will affect timing and/or combustion. The spec on my engine is < 3 bar between cylinders.

__________________
327K on 1986 W201, 602.911, 722.414 2.5 190D ("The Red Baron")
139K on 1993 W124, 104.942, 722.433 2.8 300E ("Queen")

http://farm5.static.flickr.com/4081/...0bb92d3c_m.jpg http://i370.photobucket.com/albums/o...g?t=1325284354

Do not worry about your difficulties in Mathematics. I can assure you mine are still greater.
- Albert Einstein

take a walk down memory lane...
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 07:14 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2022, 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