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 02-01-2006, 11:19 PM
Registered User
 
Join Date: Jan 2004
Posts: 52
'90 2.5td woes

Putting glow plugs in this thing and found the intake full of oil sludge... looks like the PCV has been dumping it in the intake hose. Is this PCV trouble or blowby death (156K car)? I know my way around farm equipment and if this were a JD it would be turbo or rings time!

Also, there is a fuel leak at the bottom of the inj pump, haven't looked too hard but there seems to be a right angle plastic filter and then a hose into the housing... Is this a o-ring issue or something else. Looks looks like there is a clamp bolt or something right there, haven't messsed with it. Any suggestions/experience here?

Thanks for the help.

abh3

Reply With Quote
  #2  
Old 02-02-2006, 09:28 PM
compress ignite's Avatar
Drone aspiring to Serfdom
 
Join Date: Feb 2004
Location: 32(degrees) North by 81(degrees) West
Posts: 5,554
Talking Oil Sludge...fuel leak

Try the link below for the solution to the gunk in the intake.
(But first clean out the intake [this will require removal of the intake, the sweetner is that then you can check and or
replace your glow plugs with the intake off {hose them down with PB Blaster for 4-5 days before you try to loosen them
AND put Anti-Seize compound on the G. P.s before re-installing}]

http://www.angelfire.com/space/neon/catchcan.html

The fuel leak you are describing may be the lift pump (mounted on the side of
your injection pump...it pulls diesel from the tank in the rear) or the right angle
primary fuel filter you describe (is the primary filter out in the open in the
middle of a rubber fuel line from the lift pump to the hard metal fuel line from
the tank?... if it is... look down on top of the motor mount you will see the
original PFF encased in a fuel pre-warmer powered by the engine anti-freeze
[shadetree's will not go to the trouble to replace the original config])

1st thing I'd do is check the hose clamps for proper tension with ye olde
screwdriver.

Last edited by compress ignite; 02-02-2006 at 09:35 PM.
Reply With Quote
  #3  
Old 02-02-2006, 11:32 PM
t walgamuth's Avatar
dieselarchitect
 
Join Date: Apr 2005
Location: Lafayette Indiana
Posts: 38,609
the tar

is normal for 602 and 603 engines. it is generally agreed it comes from the egr. many disable it. also most folks seem to think that synthetic oil helps avoid the tar buildup.

clean it, out disable the egr, and live happily ever after.

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
  #4  
Old 02-03-2006, 07:05 AM
Registered User
 
Join Date: Jan 2004
Posts: 52
Found the leak, it was the o-ring in the little plastic right angle fitting in the aluminum thingy with a spring inside it, a circlip holds the plastic bit in...

As far as the intake, whoops, I put it back together yesterday! The glow plugs came out easily so I didn't use anti-seize, hope I didn't screw up.

I'm getting a new o-ring this morning. It'll be great to have this thing actually crank up, not leak, etc...

Thanks for the help!

abh3
Reply With Quote
  #5  
Old 02-03-2006, 08:41 AM
t walgamuth's Avatar
dieselarchitect
 
Join Date: Apr 2005
Location: Lafayette Indiana
Posts: 38,609
are you saying

that you put it back together with the intake full of tar?

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 02-03-2006, 12:14 PM
Registered User
 
Join Date: Jan 2004
Posts: 52
You betcha! Didn't look like the stuff was going anywhere and it sounds like a common enough thing.

Besides, I well remember an old car during my teen years that was well sludged internally from lack of oil changes (and 30 years) but ran well enough... the decision was made to 'flush' the motor with some potion from the parts house and put some high detergent motor oil in it. Man, we sure knew it all at that age! Yup, sludge broke loose eventually, stopped up the oil pump pickup and that was the end of 'er!

I figure let sleeping hunds lie... ya?

abh3
Reply With Quote
  #7  
Old 02-03-2006, 12:43 PM
Registered User
 
Join Date: Dec 2004
Posts: 554
turbo

in my opinion if u let this sleeping dog lie u will be having real problems with the pistons and cylinders. the turbo needs attention else the head gasket blows on these 2.5 's. if i owned the head would come off anyway, get a good cleaning along with the top of the piston.
larry perkins lou ky
85 old cars
Reply With Quote
  #8  
Old 02-03-2006, 02:30 PM
Registered User
 
Join Date: Jan 2004
Posts: 52
If the sludge is EGR related how would that impact the head gasket?

Also, could the sludge be a turbo problem symptom? Don't these turbos smoke on load or overrun when worn?

If the sludge is that much of a problem it can be addresed when the motor is pulled to put in my wagon, assuming it runs out well enough for the effort.

Thanks

abh3
Reply With Quote
  #9  
Old 02-03-2006, 04:49 PM
Registered User
 
Join Date: Aug 2001
Location: Milford, DE
Posts: 1,558
Mine has sludge in it as well - it has the exact same amount of sludge in the intake manifold at 185K as it did when I removed the intake to check the glow plugs at 54K miles. I have no intention of cleaning it ever and I think people that report better running engines after removing the gunk are suffering from the placebo effect.

I've also never understood how EGR functions are supposed to cause gunk in the intake manifold. I can certainly see how feeding the crankcase blow-by back into the intake manifold could cause oil vapors suspended in the blow-by gases to condense on the interior of the intake manifold but how in the world does the EGR cause gunking? Unless your car is burning absurd amounts of oil there is not going to be much oil in the exhaust gas.
Reply With Quote
  #10  
Old 02-03-2006, 08:52 PM
bfd bfd is offline
Registered User
 
Join Date: Nov 2005
Location: Houston, Tx
Posts: 23
Quote:
Originally Posted by TimFreeh

I've also never understood how EGR functions are supposed to cause gunk in the intake manifold. I can certainly see how feeding the crankcase blow-by back into the intake manifold could cause oil vapors suspended in the blow-by gases to condense on the interior of the intake manifold but how in the world does the EGR cause gunking? Unless your car is burning absurd amounts of oil there is not going to be much oil in the exhaust gas.
When I replaced my glowplugs, I observed that my intake manifold and crossover pipe has about 3mm of sludge inside. I soaked both overnight in bio-diesel which made cleaning a breeze. I had read previously that the gunk can solidify and form like stalactites, whereupon they might break off and get sucked into the intake. The stuff in my manifold, however, was soft sludge, but I wasn't going to take any chances, so while I had the parts off the car, I cleaned them up.

Another thing, before cleaning, I could never actually hear the turbo whine, which always made me wonder if the turbo was working properly or not. I think that the sludge acted like sound deadening material. After cleaning, however, the turbo whine was unmistakable.

To address the nature of the sludge, perhaps extremely fine dust particles which get past the air filter are being trapped on the oily interior surface of the intake manifold -in effect causing the EGR system to act as secondary air filter of sorts.
__________________
1992 300D 2.5 Turbodiesel 96,000 miles
Reply With Quote
  #11  
Old 02-03-2006, 09:12 PM
bfd bfd is offline
Registered User
 
Join Date: Nov 2005
Location: Houston, Tx
Posts: 23
Quote:
Originally Posted by bfd
-in effect causing the EGR system to act as secondary air filter of sorts.
I meant;

-in effect causing the crankcase ventilation system to act as secondary air filter of sorts

Thinking about it, I suppose that any soot in the exhaust stream that gets fed back into the intake via the EGR system would be a major contributor to the gunk.
__________________
1992 300D 2.5 Turbodiesel 96,000 miles
Reply With Quote
  #12  
Old 02-04-2006, 09:55 AM
Registered User
 
Join Date: Dec 2004
Posts: 554
carbon build up

my opinion is that when the turbo seal leaks oil into the intake and passes with the hot gases allowed by the egr valve it gets cooked and there isnt enough light products left to completely burn when it arrives at the cylinder. this leaves a hard carbon on the head surface and the top of the piston, compression raises and there goes the head gasket, usually failes on #1 cyl next to the timing chain galley.
just my opinion, after seeing the inside of these engines.
larry perkins lou ky 85 old cars
Reply With Quote
  #13  
Old 02-04-2006, 11:36 AM
t walgamuth's Avatar
dieselarchitect
 
Join Date: Apr 2005
Location: Lafayette Indiana
Posts: 38,609
i agree with larry

when we took the head off my 90 350sdl the tar was so thick it almost completely blocked the intake ports. after the cleaning and a valve job i noticed a lot more moxie on the upper rpm ranges. also before cleaning it i would see a huge puff of black smoke come out my exhaust from time to time when cruising at hiway speed as pieces came off and went thru the engine. some folks think that these may bend rods if the blob is big enough. that seems like a stretch to me but the rods definately bend and it is pretty impossible to be sure why.

with the 602s it seems to be head gaskets more than the rods which are the specialty of the 350 engine, though they do head gaskets too.

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
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 04:02 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page