Injector noise??

[sundownersc]

I'm curious if anyone has had an injector outright fail on them and what kind of noise it blesses your engine with. A friend had a hard knock show up while driving, it starts and runs fine but begins to knock when RPMs go up.

[cdnsarguy]

There have been reports of failed injectors allowing compression back into the fuel lines.. a loud ticking is usually heard and very hot fuel line at that injector.

If an injector is firing early there is usually a bottom end knock associated as the cylinder fires too soon and that piston is forced up against the early compression by the remaining rotational force of the 7 other cylinders.

[studdy05]

i tried to rebuild one injector and it didn't go well. The engine missed noticibly and the engine had a deep pronounced rock to it at idle and just sounded ugly on the road test. I know every sound in my truck though, so it's pretty subjective. I bought a Bosch and replaced it, it fixed immediately.

[RLDSL]

A dirty slobbering injector will make the engine sound like a gasser about to throw a rod.

Before condemning the things, try running a few bottles of Diesel Purge ( 3 or 4 for this size engine ) through them. The stuff does not go in the tank, it's a bit of a production, have to get some hose and tap it in before the lift pump and run the return line back to the can ( or get a 2 liter bottle and pour all of it in there at once so you don't have to switch cans ) You run it straight till it's gone, varrying the rpms as you go.

If that stuff doesn't do the trick, it's time to get them rebuilt of buy new ones.

[sundownersc]

Thanks for all the info. We found one cylinder wet, had the injector tested and it was stuck open, piston was just along for the ride. I'll know that sound if I hear it again.