I have a 98 E300D with 140,000 miles. I have recently started to see significantly more smoke coming out of the tail pipe. Additionally, I have seen a drop in miles per gallon, around 26MPG in varying city and highway driving. I read on a parts site that fuel injectors should be replaced every 100K miles. Is this true? If so how difficult is this to do? Lastly where can I buy the fuel injectors? I can't seem to find part supplier on the web that sell the injectors.

If the fuel injector don't need replacing any thoughts on the decrease MPG's?

First check your timing chain for stretch, which would alter the whole relationship between the injection system and the engine.

Being "Spooky" I would view a T.C. replacement at 140K as cheap
insurance.

Does your model have the "Banjo Bolt" with the accompanying dirty intake
runners?

Check the vacuum/pressure lines between the I.P. and the intake for "Goo".

1. Try either a "Lubro Moly" PURGE (or if you like Red Line Diesel Fuel additive)
do a "search".
2. O.E. Bosch Injectors should last hundreds of thousands of miles , with proper
care ( I.E. no WATER or other contamination [Spelled "add on" Racor filter
with WATER seperator element].
3. Due to the outsourcing of component manufacture (to India) by Bosch ;it
is entirely possible to get a NEW set of injectors with sub-standard Pintles.
4. If you know of no one with a injector testor you may take them to an
Authorized Bosch service station to be cleaned "pop tested" AND balanced.
NOT CHEAP but assuming that you make it clear that you will only accept
your own Pintles and Nozzles in return ....You avoid the whole "India"
mess.

Thanks for the reply. Banjo Bolt? What is this? Also I.P.?

I will try some of yor suggestions. Thanks

Check the simplest thing first...smoke and bad mileage=excess fuel. When was the last time the air filter element was replaced? Start with that. Timing would be my next check. I have seen these motors with over 200K with the original injectors so don't start there.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

If you are going to take the injectors out then take the prechambers out and make sure they are clean and ream out the glow plug cavaties.

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

fuel filter (both)

__________________
Barker

I recently changed my glow plugs on two cylinders and thoroughly cleaned the intake manifold when I did it. I have 110,000 miles or so on the car now. The change in performance with a cleaned out intake manifold was remarkable. Mileage went up over 30 mpg from around 28 mpg average, and the engine runs much smoother. I am thinking of taking it off and checking it again just to get an idea of how quickly it clogs up. I would try this first, if you have never done it yet. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

I believe Mr. Smith and NHDOC have much more finely diagnosed your problem
than I.
I.P. = injection pump
Banjo bolt is an attachment point for a sensing of pressure on the intake ,
which is famous for getting clogged with "goo" and preventing the I.P.
from advancing the fuel supply in relationship to the "boost" pressure of
the turbocharger.

...it seems that our cars are much more sensative to bad fuel than gassers are, or maybe the quality control on diesel is worse than that of gasoline.

I can tell you from personal experience that the fuel near me is crap, and it is crap at every station - worse in winter but still bad now. This weekend I travelled to New Jersey and bought fuel at a Hess station. It had a marked Cetane rating of 42 on the pump. I don't know if 42 is good or bad as the stations near me do not post any ratings.

As soon as the car started running on this Hess fuel it was noticeably smoother, quieter and more powerful. My car, which never broke 30 MPG on local NH fuel since I have owned it (January 2005) got just under 34 MPG with this fuel. Maybe you simply have a run of bad fuel locally? How fast did this problem come on?

I think if you have serious problems with your engine you would notice it more than just as bad fuel economy and smoke. You would have roughness, poor idle, loss of power, etc. Your trouble may be something simple (and cheap).

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Well, if that is true, you can test it out by varying the supplier and see if that changes anything. Also put some cetane boost and see what happens. I would think that some HEET might absorb out any water that is in there just to be safe.

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

Definately don't discredit the bad fuel notion - I recently filled up at a Shell station on Farrow Rd in Columbia, SC - my mileage was appalling. Didn't run too much different than normal but MPG's suffered bad. Other fuel I've had the mileage was also bad and really smokey.

I use Redline Diesel 85 Fuel additive every tank. 3 ounces per every tankful

__________________
#dieselFLEET
---------------
'97 E300
'99 E300

Don't waste your money replacing the injectors have yours tested and rebuilt. My friends E300D with 150k at the time had only two injectors with a weak spray pattern. Pop pressure and everything else was fine.

I would sudjest pulling the intake manifold and cleaning it out.

At 140k miles the timing chain on a 606 should have almost no stretch. I wouldn't even think about changing the chain until you pass 300k.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Mine had a degree and a half of stretch

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

1) Don't replace injectors... test them and clean/repair as necessary. Replacement would not be common.

2) The banjo bolt was last used in 1985 on the OM617 engine. The later cars had a straight fitting in the manifold that can still plug up with carbon, however this will reduce power drastically when it blocks the signal to the ALDA. I'm not even sure if the computer-controlled IP on the 606.96x has a mechanical ALDA like the older models (<1995).

3) Cleaning the intake will help the OM606 engines only, because of the resonance flaps. Cleaning the intake on a 617 or 602/603 will only make you feel better, it won't give any power or MPG gains.

4) The factory spec for timing chain replacement on all OM60x engines is 4 degrees. Less than 4, leave it alone. 4 or more, replace it. Very simple. Usually not needed under 250kmi unless the engine was not maintained well (i.e., infrequent oil changes).

__________________
Dave
Boise, ID
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