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 12-04-2009, 02:27 PM
Dobroman's Avatar
Registered User
 
Join Date: Sep 2009
Location: Hathaway Pines Calif.
Posts: 35
Diesel cap question

I have this 84 300D and
I am wondering what could be causing diesel to be leaking from the gas cap (or diesel cap). There is a small amount of diesel showing it self on the paint around the door to cap and a some diesel sitting in the compartment. Not a lot but I don't think that this is right.
Is the cap bad or is it some kink of pressure issue in the system?

Jimmy

Reply With Quote
  #2  
Old 12-04-2009, 02:31 PM
snookwhaler's Avatar
Linesider
 
Join Date: Feb 2009
Location: Treasure Coast, FL
Posts: 1,417
You probably just need a new seal. Or you can replace the cap.
__________________
AJ

1985 300D (SOLD)

Reply With Quote
  #3  
Old 12-04-2009, 02:37 PM
Dobroman's Avatar
Registered User
 
Join Date: Sep 2009
Location: Hathaway Pines Calif.
Posts: 35
Thanks , I'll try that . It makes sense to me.
Reply With Quote
  #4  
Old 12-04-2009, 02:40 PM
dadette123's Avatar
what little I know
 
Join Date: Nov 2009
Location: Houston
Posts: 240
check your tank vent
Reply With Quote
  #5  
Old 12-04-2009, 02:41 PM
whunter's Avatar
Moderator
 
Join Date: Dec 2003
Location: Metro Detroit, Michigan
Posts: 17,357
Answer

The engine oil fill cap is identical = you can swap them.

Another possible answer = The fuel tank vent may be plugged.



.
__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Prototype Vehicle build.
Prototype Fleet Durability
Prototype vehicle instrumentation.
Technical Quality Auditor.
Automotive Technical Writer

1973 300D
1973 309D - stolen
1978 280SE
1980 240D
1983 300D
1984 190D

Last edited by whunter; 10-02-2010 at 04:02 PM.
Reply With Quote
  #6  
Old 12-04-2009, 10:10 PM
Dobroman's Avatar
Registered User
 
Join Date: Sep 2009
Location: Hathaway Pines Calif.
Posts: 35
Thanks, where is the vent for the fuel tank?
Reply With Quote
  #7  
Old 12-04-2009, 10:17 PM
Registered User
 
Join Date: May 2007
Location: Out in the Boonies of Hot, Dry, Dusty, Windy Nevada
Posts: 9,585
Here is a link to the oil cap seal

http://www.allpartsexpress.com/ShopByVehicle.epc?q=1984-MERCEDES--BENZ-300dt--/--L5--998cc--3.0l--Diesel--Fi--Turbo-Engine--Seals--Gaskets--Sets&yearid=1984%40%401984&makeid=MERCEDES+BENZ%40%40MERCEDES+BENZ%40%40X&engineid=1193789%40%40300DT++%2F+L5%2D2998cc+3%2E0L+DIESEL+FI++Turbo%40%40300DT&catid=Engine+Seals%2C+Gaskets+%26+Sets%40%40Engine+Seals%2C+Gaskets+%26+Sets&subcatid=Oil+Filler+Cap+Gasket@@Oil+Filler+Cap+Gasket&mode=PA

here is the fuel cap seal

http://www.allpartsexpress.com/ShopByVehicle.epc?q=1984-MERCEDES--BENZ-300dt--/--L5--998cc--3.0l--Diesel--Fi--Turbo-Exhaust--Fuel--Tank&yearid=1984%40%401984&makeid=MERCEDES+BENZ%40%40MERCEDES+BENZ%40%40X&engineid=1193789%40%40300DT++%2F+L5%2D2998cc+3%2E0L+DIESEL+FI++Turbo%40%40300DT&catid=Exhaust+%26+Fuel+Tank%40%40Exhaust+%26+Fuel+Tank&subcatid=Fuel+Filler+Cap+Seal@@Fuel+Filler+Cap+Seal&mode=PA

Much cheaper than this

http://www.allpartsexpress.com/ShopByVehicle.epc?q=1984-MERCEDES--BENZ-300dt--/--L5--998cc--3.0l--Diesel--Fi--Turbo-Exhaust--Fuel--Tank&yearid=1984%40%401984&makeid=MERCEDES+BENZ%40%40MERCEDES+BENZ%40%40X&engineid=1193789%40%40300DT++%2F+L5%2D2998cc+3%2E0L+DIESEL+FI++Turbo%40%40300DT&catid=Exhaust+%26+Fuel+Tank%40%40Exhaust+%26+Fuel+Tank&subcatid=Fuel+Filler+Cap@@Fuel+Filler+Cap&mode=PA

The vent is under the car on the drivers side. It is sort of forward of the L/R wheel but behind it. It has a bell shaped end pointing down.
Charlie
__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Last edited by charmalu; 12-04-2009 at 10:25 PM.
Reply With Quote
  #8  
Old 12-04-2009, 10:37 PM
Dobroman's Avatar
Registered User
 
Join Date: Sep 2009
Location: Hathaway Pines Calif.
Posts: 35
Thanks Charlie! I'll check that out. Maybe I can keep that diesel off my paint.

BTW My heater is now working the way it was designed. It is really nice. Changed the thermostat and cut a hole in the dash mat so the sensor would work and got a piece of pipe insulation from Lowes and put it where the old foam hose was missing behind the glove box.
Reply With Quote
  #9  
Old 10-02-2010, 03:01 PM
Registered User
 
Join Date: Mar 2005
Location: SoCal
Posts: 660
Quote:
Originally Posted by whunter View Post
The engine oil fill cap is identical = you can swap them.
Is this also true with the plastic cap? Just lost my original fuel cap. Fortunately i have an extra plastic oil filler cap. It looks smaller but it went in.
__________________
'85 300D Cal 280,000 miles
'07 C230 37,000 miles
Reply With Quote
  #10  
Old 10-02-2010, 04:02 PM
whunter's Avatar
Moderator
 
Join Date: Dec 2003
Location: Metro Detroit, Michigan
Posts: 17,357
Yes

Quote:
Originally Posted by my123ca View Post
Is this also true with the plastic cap? Just lost my original fuel cap. Fortunately i have an extra plastic oil filler cap. It looks smaller but it went in.
yes.
Reply With Quote
  #11  
Old 10-02-2010, 05:13 PM
Banned
 
Join Date: Aug 2008
Location: Texafornia
Posts: 5,493
You need to clean the drain hole out at the bottom of the door pocket, running the plastic coated steel cable down thru is good for that.
Reply With Quote
  #12  
Old 10-03-2010, 12:05 AM
vstech's Avatar
DD MOD, HVAC,MCP,Mac,GMAC
 
Join Date: Mar 2006
Location: Mount Holly, NC
Posts: 26,337
actually, the oil and fuel caps are not exactly identical.
put the oil cap on your valve cover, and the handle aligns with the valve cover, the fuel cap sits kittywonkous.
also, the gasket is smaller on the gas cap.
they are indeed interchangeable thought and both will function well in either location.
__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!
Reply With Quote
  #13  
Old 10-03-2010, 12:55 AM
Registered User
 
Join Date: Mar 2005
Location: SoCal
Posts: 660
Thanks for the replies. Going on a long trip with the wife and doter tomorrow with a full tank of fuel. I dont want them complaining of diesel smell. Will go to the dealer to get the right part on monday.
__________________
'85 300D Cal 280,000 miles
'07 C230 37,000 miles
Reply With Quote
  #14  
Old 10-03-2010, 03:30 AM
Registered User
 
Join Date: May 2007
Location: Out in the Boonies of Hot, Dry, Dusty, Windy Nevada
Posts: 9,585
Quote:
Originally Posted by vstech View Post
actually, the oil and fuel caps are not exactly identical.
put the oil cap on your valve cover, and the handle aligns with the valve cover, the fuel cap sits kittywonkous.
also, the gasket is smaller on the gas cap.
they are indeed interchangeable thought and both will function well in either location.
This is true. My oil cap wasn`t inline with the VC like I had seen on other engines. I thought the two pieces of the cap had twisted around.

It wasn`t till i was at PNP (of all places) that I noticed that the oil cap has OEL stamped on them (the metal one`s), and it was in line with the VC.

definately don`t want a plastic cap, the one I had leaked and made a mess. and the metal caps look better and will polish up nice. .

They aren`t available, so grap them when you see them.

Charlie
__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works
Reply With Quote
  #15  
Old 10-03-2010, 10:41 AM
Registered User
 
Join Date: Sep 2004
Posts: 8,730
Quote:
Originally Posted by vstech View Post
they are indeed interchangeable thought and both will function well in either location.
Really? Does the oil cap have the pressure relief vent like the fuel cap?

"Fit" is one thing; "Function" is another.

Quote:
Originally Posted by Dobroman View Post
I am wondering what could be causing diesel to be leaking from the gas cap (or diesel cap).
Failure to engage both lugs on the cap is one possible cause.

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 04:10 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, 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