300 cd Injector Line Leak... Now Ugly Knock

[alyssak78]

Okay... take a picture of this.

Girlfriend drives around the block to the store. When she starts the car to return home ugly knocking starts. Upon her immediate return (short trip, less than a mile) I discover fuel line leak at the injector side. Replaced brass line, still knocking. Sounds bad, feels bad, is this bad?

Could the leak have killed the injector? Could it have created an instant bad valve?

Any help most appreciated!

[greasybenz]

the brass line should have been ok. You have to replace the injector heat shield and tighten the injector. A loose/leaky injector will create the knock and rough idle it shouldnt kill the injector or mess up a valve.

EDIT: refer to dieselgiants write up on the bosio nozzles. Towards the end where he explains the heat sheild, that should help you out.

http://dieselgiant.com/mercedesinjectornozzlereplace.htm

[barry123400]

We are talking about a line from the pump to the injector? How did you deal with the pump end of the line? Any chance you disturbed the pump fitting by overtightning? Start by loosening the injector line at the injector and seeing if the knock stops. There are a whole sequence of tests that one can do to pin it down if they become required. The important thing is to go slow and think. Needless to say the above is only my opinion. I am going to make a couple of assumptions here. Replacing the injector line stopped the leak? Also there is no chance what you describe has hurt an engine valve.

[SD Blue]

Are you talking about the hard line from the pump to the injector?

I would be more suspect of the return fuel lines that go from injector-to-injector. When they leak, it could cause the same symptoms and appear as a leak from the injector or hard line.

BTW, what did you replace it with?