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
  #16  
Old 02-11-2009, 06:24 AM
Admiral-Third World Fleet
 
Join Date: Feb 2002
Location: Central FL
Posts: 3,068
any oil consumption observations yet?
__________________
80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)
Reply With Quote
  #17  
Old 02-11-2009, 06:41 AM
Gene
 
Join Date: Mar 2007
Location: Buffalo NY
Posts: 1,082
Yes, my bio-buggy's oil consumption went UP after I had the cylinder head redone.
Reply With Quote
  #18  
Old 02-11-2009, 07:26 AM
winmutt's Avatar
85 300D 4spd+tow+h4
 
Join Date: Apr 2006
Location: Atl Gawga
Posts: 9,325
And still less smoke? Man I really need to do this for my car.
__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1987 300D Sturmmachine
1991 300D Nearly Perfect
1994 E320 Cabriolet
1995 E320 Touring
2001 Eurovan FOR SALE
1985 300D car, sold and missed.
OBK #42
Reply With Quote
  #19  
Old 02-11-2009, 09:04 AM
Ether's Avatar
Go S Class or go home
 
Join Date: Oct 2001
Location: Lawrenceville, GA
Posts: 758
I can't really give an accurate answer on oil consumption until I do my ceremonial 1k check and refill to my reference point on the dip stick. That should be about the middle of next week so I will report then.

Yes winmutt still dramatically less smoke in stop and go traffic and none on cold starts.
__________________
Joe

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1980 300SD - 495k miles - 'The Ambassador'
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Former Family Members
95 C280
73 280SEL
90 300D
87 300SDL (X2)
86 560SEL
84 300D
80 300SD

Reply With Quote
  #20  
Old 02-11-2009, 10:47 AM
Stevo's Avatar
Registered User
 
Join Date: Apr 2002
Location: NW WA
Posts: 6,285
thanks for the feed back, keep it coming.
__________________

1985 Euro 300TD 5 spd 220K
1985 Euro 240D 5 spd 130K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
Reply With Quote
  #21  
Old 02-11-2009, 09:58 PM
KAdams4458's Avatar
Mmm! Diesel!
 
Join Date: Apr 2007
Location: Snohomish, WA
Posts: 1,420
This report gives me great hope that my engine is not completely trashed! Less pressure in the valve cover? My car had a similarly seepy cap until I replaced the gasket, but tightening up the gasket on the cap made the fresh valve cover gasket seep. There is so much pressure inside of the valve cover that it blows oil through the vent and directly in to the intake in rather large amounts.

I'll be on the edge of my seat until the oil consumption results are in. This is really exciting!
__________________
- K.C.Adams

'77 300D Euro Delivery
OM617 turbo / 4-speed swap
404 Milanbraun Metallic / 134 Dattel MB-Tex

Current status:
* Undergoing body work


My '77 300D progress thread

Reply With Quote
  #22  
Old 02-12-2009, 04:38 AM
Registered User
 
Join Date: Sep 2001
Location: central Texas
Posts: 17,277
This is a valuable maintenance job which should be done more often than it is...
While one has it opened up to that level for the valve stem seals I would suggest new valve springs and valve rotators at the same time... and perhaps new locking and top caps for the valves.... these are things suggested by the FSM on a periodic basis and it makes sense to save the labor of taking it back down to this level by doing it while it is opened up. These things are amazingly cheap compared to their value to an engine.

Last edited by leathermang; 02-12-2009 at 04:39 AM. Reason: spelling
Reply With Quote
  #23  
Old 02-12-2009, 04:17 PM
Dionysius
 
Join Date: Jan 2006
Location: Seattle WA
Posts: 261
Lightbulb

Quote:
Originally Posted by KAdams4458 View Post
This report gives me great hope that my engine is not completely trashed! Less pressure in the valve cover? My car had a similarly seepy cap until I replaced the gasket, but tightening up the gasket on the cap made the fresh valve cover gasket seep. There is so much pressure inside of the valve cover that it blows oil through the vent and directly in to the intake in rather large amounts.

I'll be on the edge of my seat until the oil consumption results are in. This is really exciting!
This is a very important thread. The results will be very welcome and then we will have to explain what is going on. If the pressure in the Valve Cover is reduced by the Seals an explanation will be required. The Seal is more likely to prevent ingress of oil and some pressure into the Stem Guide interstitial zone but I am not as clear as to how it can hold pressure back from entering the Valve Cover. Any ideas??
__________________
Dionysius
Reply With Quote
  #24  
Old 02-12-2009, 04:20 PM
winmutt's Avatar
85 300D 4spd+tow+h4
 
Join Date: Apr 2006
Location: Atl Gawga
Posts: 9,325
I would think gasses passing the seals when the exhaust valves were open, although there is a good amount of pressure coming up, do the valve guides seal as well?
__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1987 300D Sturmmachine
1991 300D Nearly Perfect
1994 E320 Cabriolet
1995 E320 Touring
2001 Eurovan FOR SALE
1985 300D car, sold and missed.
OBK #42
Reply With Quote
  #25  
Old 02-12-2009, 04:29 PM
Shawn D.'s Avatar
Registered User
 
Join Date: Sep 2006
Location: Alpharetta, GA
Posts: 509
You know, folks, that blowby comes from rings as well. In fact, rings are probably the major culprit in almost every case.
Reply With Quote
  #26  
Old 02-12-2009, 04:51 PM
Dionysius
 
Join Date: Jan 2006
Location: Seattle WA
Posts: 261
Quote:
Originally Posted by Shawn D. View Post
You know, folks, that blowby comes from rings as well. In fact, rings are probably the major culprit in almost every case.
If the Seals make a noticeable reduction in Valve Cover pressure what I am saying is that it will be difficult to explain. The challenge here is to keep an open mind and analyze the data we get from Mr Ether who is doing a great job in providing us with the data.
__________________
Dionysius
Reply With Quote
  #27  
Old 02-12-2009, 05:40 PM
Registered Hack
 
Join Date: Mar 2008
Posts: 4,612
On engine heads with fair mileage it is quite reasonable to believe that the valves do not seat as crisply or uniformly as the they once did on a freshly ground head. These gasses pass into the head ports and add to the existing pressures- most likely minimal by comparison due to the volume that passes.

The minutia of surface area available at the valve steam seal on the combustion side may allow the seal to effectively retain the pressure of exhaust/ intake gasses that are found in the manifolds and their respective parts. The valve guides and stems do some sealing but after time clearance accumulates and sections of the valve movement have more clearance in the guide / stem interface.

Whereas older seals do not have the elasticity to allow the tensioning ring to function as designed.


...just a guess.
__________________


Last edited by jt20; 02-12-2009 at 05:54 PM.
Reply With Quote
  #28  
Old 02-12-2009, 05:52 PM
pizzachef's Avatar
Registered User
 
Join Date: Jan 2007
Location: New Cumberland, PA
Posts: 833
I have a considerable amount of smoke at startup and a little bit just driving around with the car fully warmed up. This is on a '74 240D.

NHDOC replaced the valve stem seals in his '75(ish) 240D and in this thread, he said it didn't reduce his oil consumption much:
Valve Stem Seal Question

Hopefully your results are different. I'd like to do this on my w115 as well, so I'll be waiting to see how you make out. Thanks for letting us know!
__________________
1985 300TD-euro 352,000 mi
1974 240D (1?)52,000 mi - has a new home now
Reply With Quote
  #29  
Old 02-12-2009, 06:03 PM
Bajaman's Avatar
Registered User
 
Join Date: Mar 2005
Location: Bern, Switzerland
Posts: 713
I would assume that any appreciable blow by from the valve stem seals is going to be fresh air from the turbo, or exhaust... neither having anything to do with valve functionality.
__________________
For Sale: 1982 MB 300TD
1995 Chevrolet Suburban 6.5TD

Sold: 1980 IH Scout Traveler- Nissan SD33T Diesel
Reply With Quote
  #30  
Old 02-12-2009, 06:13 PM
Registered Hack
 
Join Date: Mar 2008
Posts: 4,612
which is greater: pressure from the piston on its exhaust stroke or pressure from combustion? They are both plumbed into the same region. Any, even small amounts, combustion gases passing the valves will add to manifold pressure. - there is always a cylinder burning while another is exhausting, combine them.

Surely, it is negligible. Agreed, that the pressures in the manifolds are exhaust back pressure / turbo boost and are the same pressures working on the valve seals.
__________________


Last edited by jt20; 02-12-2009 at 09:10 PM.
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 11:49 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