Injectors bubbling

[Jjb8988]

Allrighty then I'm a nub to forums and diesels so type slow and clear. I have 2 injectors that are bubbling a little from the big nut on the bottom of the sticks. I'm guessing there not supposed to do that. I also hear a slight knock. My valve covers are leaking a little there on my list to do. So my questions are am I doing any damage driving? what do I do with the sticks? New sticks? New seals for the sticks? what do I torque the valve covers to? And what valve cover gaskets do you prefer? I appreciate any feed back.

[PToombs]

Just make sure the nuts on the injectors are tight, IIRC it's 44 ft lbs of torque. You can go a little more, but don't go crazy. If they don't seal, then you may need to replace the copper washers on the bottom of the injector. A knock could be anything from a loose wrist pin to a rod, to the lift pump on the cam lobe....... The valve covers use a shoulder bolt, I just snug them down and call it good. Most valve cover gaskets are good, I prefer the silicone ones, they stay soft longer and seal better.

[RCCUMMINS89]

An injector not firing will also cause a "thump" or knock. But if they are actually bubbling, it means you are drawing in air somewhere in the system.

Does it smoke white, or miss?

[PToombs]

RC, they are bubbling where they are screwed into the head. Only other possible thing is the injector body unscrewed, but that's rare.

[RCCUMMINS89]

True, read it wrong. Minor compression loss is what is showing bubbles. Yes, crank the hold down nuts down more.

From personal experience... I've never had mine seal at the recommended 44 ft/lbs. I've always needed more like 70, especially with the aftermarket thin washers.

[PToombs]

I think I went to about 50 on mine. 70? Wow. They are german injectors, so they gotta be gutin tite!

[Jjb8988]

PT thanks I'll go silicone on the gaskets. Do you have a brand you prefer? RC I'm starting to think the knock is my head because no one else can hear it. As for smoke or haze- I always start her up for a few min. Before I drive but I do get a white smoke the first time I step on the gas then it clears up totally I just figured I need to change the fuel filter. She's due for a oil change in 500 miles. It's got 160 thousand original miles and I'm the 3rd owner I have no idea if there aftermarket washers. I appreciate the quick response and typing slowly.