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Diesel Fuel Injector replacement

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How difficult is it to replace Diesel Fuel injectors on a 1998 E300-D. Is the intake manifold difficult to remove and replace ? Is purchasing a Bosch OEM injector from a Bosch dealer OK, as opposed to the Mercedes dealer ?
Don

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Injectors are on the top of the cylinder head. Although not difficult, removal of the intake manifold not required. Bosch is OE, but why would you be considering replacement vis a vis rebuild?

A tad more info would allow a much more comprehensive response ;)

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Dick
Thanks. I was told that the injectors on that model year are under the intake manifold. When I look under the manifold, I can see the return lines. Am I incorrect ??
Thanks
Don

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Dick
Also, where can I find the rebuilt injectors. I have looked around but have been unsuccessful for the E300 Turbo Diesel, 1998. I am only going to keep the car less than one more year. I hoping that MB 2007 E300 Diesel will have the four matic with the new V-6. Have you heard anything.
Thanks again.
Don

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Dick
The injectors have become very noisy, and at 185,000 miles I was told now is a time to replace them. I also had some leaking pump seal replaced. The car runs rough when you first start it, but smooths out when warmed up. However, when I am driving at highway speed, I still detect a slight sputter that is errartic. Whe I spoke to Bosch, they felt it was the injects. The car also smokes a bit more at idle, and smells of unburned fuel. I am a little concerned that the high speed occational sputter may also be related to the pump. My brother-in law is a diesel mechanic, but has not been able to look at it yet. Thoughts.
Thanks for the help and advise.
Don

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OK, a few things:

1. The pipe that goes over the top of the engine is not the intake manifold; But it does have to come off to access the injectors. Remove the 2 allen/hex bolts that attach the pipe at each end. Remove the 10mm bolts that hold the EGR tube and the brackets to the side of the engine. There are 2 brackets, one for the pipe and one for the EGR valve. You need to remove all of this to get the pipe back in again. Use some silicone lube on the O ring seals.

2. Remove the plastic cover to expose the injectors. Before you go any further, make sure the intake "hole" is clear and start the engine. Feel each of the injector lines and see if you can tell which one(s) making the noise. Sometimes its just the routing and line brackets that make all the racket.

3. Leave the pipe off, keep everyone away, YOU REALLY DON'T WANT ANYTHING GOING INSIDE THE INTAKE WITH THE ENGINE RUNNING, and Diesel Purge the engine. See if that quiets the beast. If not, find a truck/Diesel repair place in Yellow pages that's an authorized rebuilder for Mercedes/Bosch injectors and injector pumps. Have your's rebuilt. You should get the correct injector socket to R&R the injectors too. Its a specially machined 27mm deepwell. Snap On has it. Without it, you can screw up the nipples or fuel line attachment and will not be able to get the injector tight enough. If you remove the injectors don't forget to replace the seal washers. Pay attention to their orientation. When you reinstall the injectors, start it up and let it idle for 10-15 minutes to check for fuel seepage at the base of the injectors. If they are leaking, snug them up a little more and repeat. Also get new fuel return line and replace all the loops.

Last but not least, make sure you have the service information BEFORE you start "wrenching".

If your BIL is a Diesel wrench, he will know the right place to get the injectors rebuilt and have the socket too :D

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