Diesel Leakage - PeachParts Mercedes-Benz Forum

nyko46 · #1 12-07-2010, 01:15 PM

My 1984 300 SD Mercedes Benz has a small leakage of diesel on the second cylinder from front of the engine to the driver. I had the injector removed and the metal seal replaced but it did not stopped completly the leak.
I was woundering and I still not knowing if the part where the injector is threaded in has or not some seal between block and this part which I don't know the technical name. It seems to have a way to remove this part because there are two slots on it which probably is to fit some special tool to have it unthreaded and threaded again in the engine block but it is only my guessing. If someone can give me a help on it I will really appreciated.
Thanks very much.

Nivaldo

tankowner · #2 12-07-2010, 01:24 PM

Quote:

Originally Posted by nyko46

My 1984 300 SD Mercedes Benz has a small leakage of diesel on the second cylinder from front of the engine to the driver. I had the injector removed and the metal seal replaced but it did not stopped completly the leak.
I was woundering and I still not knowing if the part where the injector is threaded in has or not some seal between block and this part which I don't know the technical name. It seems to have a way to remove this part because there are two slots on it which probably is to fit some special tool to have it unthreaded and threaded again in the engine block but it is only my guessing. If someone can give me a help on it I will really appreciated.
Thanks very much.

Nivaldo

Are you sure it isn't the braided fuel return lines that isn't leaking fuel onto the injector? When the line gets old it cracks and weeps fuel out onto the injector. You spray the injector and surrounding area down with brake cleaner and let it dry. If the lines look wet, dry them with some paper towels. Then start the engine and see where the fuel leaks from.

vstech · #3 12-07-2010, 01:29 PM

you are sure diesel is leaking from the injector? since you removed it, I guess you replaced the soft lines between the injectors, they are usually the leaking part. is there any chance the hard nuts are cracked and leaking?
http://www.dieselgiant.com/mercedesinjectornozzlereplace.htm

nyko46 · #4 12-07-2010, 07:52 PM

Quote:

Originally Posted by tankowner

Are you sure it isn't the braided fuel return lines that isn't leaking fuel onto the injector? When the line gets old it cracks and weeps fuel out onto the injector. You spray the injector and surrounding area down with brake cleaner and let it dry. If the lines look wet, dry them with some paper towels. Then start the engine and see where the fuel leaks from.

Your idea make sense but it is not the problem because this was the first thing that I tryed was to change these hoses. After that I removed the injector and change the seal between the injector and the part where it is threaded in. Can that part leak from inside or between engine block and injector?
Anyway thanks for help.

nyko46 · #5 12-07-2010, 07:59 PM

Quote:

Originally Posted by vstech

you are sure diesel is leaking from the injector? since you removed it, I guess you replaced the soft lines between the injectors, they are usually the leaking part. is there any chance the hard nuts are cracked and leaking?
http://www.dieselgiant.com/mercedesinjectornozzlereplace.htm

The nuts are fine and clean with brake cleaner helped me to have that area clean to be possible to see from where the leak was coming and the only place from I can see it coming was from injector and the part under it or, the part between engine block and injector. As I said in the thread, I don know if there are some seal under it or if it is loose since I don't have the tool to check for looseness

vstech · #6 12-07-2010, 08:14 PM

it's REALLY Hard to tell where fuel is coming from, but best bet is to totally clean the valve cover, and head around the injector. clean the injector and spray liberally with brake spray and allow to totally dry. make sure there is NO liquid left on the block before you start the car. get compressed air, and a vacuum if needed, but verify NO traces of liquid are left around the area you want to look.
as soon as you are certain the area is totally dry, have someone start the car while you look the area over and look for fuel leak.
you will find it.
I really doubt it's coming from the injector to the head seal.
likely it's a cracked injector body, a nut, a braided return line or even motor oil seeping from the valve cover.

nyko46 · #7 12-07-2010, 08:31 PM

Quote:

Originally Posted by vstech

it's REALLY Hard to tell where fuel is coming from, but best bet is to totally clean the valve cover, and head around the injector. clean the injector and spray liberally with brake spray and allow to totally dry. make sure there is NO liquid left on the block before you start the car. get compressed air, and a vacuum if needed, but verify NO traces of liquid are left around the area you want to look.
as soon as you are certain the area is totally dry, have someone start the car while you look the area over and look for fuel leak.
you will find it.
I really doubt it's coming from the injector to the head seal.
likely it's a cracked injector body, a nut, a braided return line or even motor oil seeping from the valve cover.

The message is very helpful.
I remember to see a Mercedes mechanic using compressed air to check fuel leak many years ago in the same Mercedes in NY when I got a lot of snow and have nowhere to do any job in this car. The guy at that time used compressed air and he found leakage on the seal at the main fuel filter.
Thanks for your message and I will keep working on it and let all people involved in this subject know where was the leak.
Thanks again