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 12-14-2005, 06:38 PM
Registered User
 
Join Date: Jul 2004
Location: Miami FL
Posts: 253
Injection pump?

Im starting to think my injection pump or its timing has problems. Upon start up my idle is really low (like 500) and I have to press on the accelerator (while in park) just a bit to get it up and after I release it settles to about 700. Now, while the engine is still cold (very cold with the current temperature outside) the engine lopes at idle quite a bit and shakes until it sputters a few times( and with each sputter a lot smoke spews out) and then it sits quite niceley with very little shaking. But there is still a noticeably loud engine noise (or at least louder than it was not too long ago) coupled with clapping/slapping sound coming from the engine. As I pull out of park and accelerate, that clapping/slapping sound progressiveley increases with engine speed and the engine noise becomes progressiveley louder as well (louder than I ever remember it being). Then upon pulling up onto the highway the engine surges when holding the acceleration steady and stumbles and spews smoke once again until it finally settles. The loud noise of the engine continues until the engine warms up fully and is driven for a little while and then smooths to normal.

To start eliminating the possible sources of the problem/s, I intend to do the following. I plan on changing the oil this weekend with Mobil1 0-40 (as per reccomendations on this site) even though I changed it at the end of october (possibly this is causing the loud engine noise?). I also want to put in my new idler adj. pin. And I finally have located the source of a minor air leak which was creating some foamy bubbles in the prefilter. In addition ill be running at least one can of diesel purge. Afterwards I might go get its compression checked. My fuel filters are less than 1000 miles old so I wont be changing those, but I have heard some mention of a tank strainer and If I knew where it was Id check that out. But, my problem is I still am not sure of exactly what is at fault here. If you guys could help and offer possible causes and solutions I would be very greatful. Would the cold weather be partly to blame here?

__________________
1983 300SD White with Grey interior
Reply With Quote
  #2  
Old 12-14-2005, 06:55 PM
Craig
Guest
 
Posts: n/a
The first thing I would do is track down the source of the air leak in the fuel system. The tiny bubbles are not normal and have to indicate that air is getting into the fuel system someplace. That is the likely cause of at least some of your issues. You need to carefully check all the hoses and connections in the fuel line until you find it.

BTW (at the risk of starting the dreaded oil thread), I am not comfortable using 0W40 in a 617. I found that Mobil 1 5W40 (Truck and SUV) spins very well in cold temperatures. Also, if you compare the spec sheets for 0W40 with 5W40 you will see the 5W40 is more appropriate for diesels:

http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_Truck_SUV_5W-40.aspx

Just my opinion.
Reply With Quote
  #3  
Old 12-14-2005, 06:59 PM
Registered User
 
Join Date: Jul 2004
Location: Miami FL
Posts: 253
Thanks Craig for the oil info. But, do you really think the air causing those foamy bubbles is the source of this problem? I have had these for a while, in fact less than I used to since I switched out my primer pump.
__________________
1983 300SD White with Grey interior
Reply With Quote
  #4  
Old 12-14-2005, 07:10 PM
Craig
Guest
 
Posts: n/a
Quote:
Originally Posted by JMan300sd
Thanks Craig for the oil info. But, do you really think the air causing those foamy bubbles is the source of this problem? I have had these for a while, in fact less than I used to since I switched out my primer pump.
I can't be sure that's your only issue, but I do know those bubbles shouldn't be there. If I understand correctly, these symptoms are only occurring when the engine is cold, then it runs normally when the engine reaches normal temperature. My best guess is that you car was more "forgiving" of this air in the system during warm weather, and now that it's cold you are seeing the effects. In any event, I would take care of that issue first just to eliminate it as the cause. I would start by checking the entire length of the fuel line looking for wet spots. If your lucky, this will be a very cheap fix. Anyone else?
Reply With Quote
  #5  
Old 12-14-2005, 07:11 PM
t walgamuth's Avatar
dieselarchitect
 
Join Date: Apr 2005
Location: Lafayette Indiana
Posts: 38,604
it also

sounds as if yoiu may have some glow plug issues.

this last time i put in mobil 1 10w40 diesel rated. before that i used mobil one 20w50 but i couldnt find it this time. i have a 603.

i always have run rotella 15w40 in my 617s. and i too would not run 0w40. i think you will not find that in the owners manual for recommended weights. i have often gone thicker but never thinner than recommended.

tom w
__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.
Reply With Quote
  #6  
Old 12-14-2005, 07:18 PM
Registered User
 
Join Date: Nov 2004
Location: Nova Scotia, Canada.
Posts: 6,510
For a starter I would put a good dose of fuel treatment in the tank. The slapping noise I might suspect something with the chain guides and tensioner. Although it could be piston slap with a very cold engine but really do not have a clue myself at this point.On the otherhand if that chain is running loose when cold could do a lot of things I imagine. But why would it cease when warmed up? If no reasonable answers are forthcoming on this site I would post it in the tech section as well. Engine noises are generally hard to describe in my opinion. Its reasonable to conclude the injection pump is not making a slapping noise internally in my limited experience. Also unlikely you developed more than one malfunction at same time so chase the slapping noise first. Again just my opinions and probably wrong with my limited experience plus I cannot actually hear your engine noise. You should be able to localise it to the front,middle, or rear of the engine though. Is the vaccum pump having a heart attack? Use a large screwdriver as a stethascope and put up more information. Do not procastinate or run that engine a lot until you have located or have a general ideal of where the major noise is coming from. That is again just a thought and may be totally groundless. It is just what I would do and is not a scare tactic

Last edited by barry123400; 12-14-2005 at 07:27 PM.
Reply With Quote
  #7  
Old 12-14-2005, 07:24 PM
Craig
Guest
 
Posts: n/a
Also, check out this thread regarding air in the fuel system:

I'm baffled and at wit's end!?!?!?!?!
Reply With Quote
  #8  
Old 12-14-2005, 09:00 PM
Registered User
 
Join Date: Jul 2004
Location: Miami FL
Posts: 253
Its deffintley not glow plug related, I just changed them all out and the relay as well at the same time I changed the fuel filters. I did clean out the banjo bolt last weekend and refitted a new vaccuum line to it, but I doubt this is related to my engine noises and stumblings. I think perhaps the louder engine noise might somehow be drive train related but the slapping sound deffinetley comes from the injector pump side of the engine. I also did give my car a full bottle of red line diesel additive when I filled up this weekend.

I only mention and think the injector pump might be at work here because of the stumbling and surging upon relaitveley higher acceleration off the onramp onto the highway. Ive noticed that during these instances, deccelerating and reaccelrating does not solve the problem. I pretty much need to accelrate steadily through it as best as possible. If the air leak was the source wouldnt I have problems stalling?

Barry, I am concerned about what you said about the chain guides or tensioner. You know, I would be more than willing to go to an indy repair guy, but as I am new up here in new jersey I am very reluctant to venture out and use just any mechanic. Also I dont have a garage and have to park on the street (it really sucks) and working on the car in this cold is miserable. Its irrelevant, but I wonder if any warehouses exist where you can pay to work on your car there? Probably not

__________________
1983 300SD White with Grey interior

Last edited by JMan300sd; 12-14-2005 at 09:07 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 12:10 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, 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