There is a thumping noise when my truck is running, and is loudest comming from the intake. does anyone else have this or heard this and know what it is? Thanks

 

You ran so hard, you sucked a gremlin through the turbo. He's hung in heater grid and raising heck trying to get out. Remove air horn to allow exit. JMHO

 

I'm LMAO

 

Could be loose bracket on high pressure injection lines. Check all bolts on these brackets.

 

seriously... Lol. but the injection lines are tight and torqued to specs. could it be valves?

 

It's possible... make sure you check clearance with engine cold.

 

Oh wait, it cant be the valves, because they were all adjusted the day before yesterday. And it made this noise before i put the new head on.

Well it dosnt seem to be doing harm, i was just curious on what it was.

 

If a injector is damaged or partially plugged off. or dribbling instead of spraying a nice pattern it can cause a knocking noise. The noise can be from a slight thumping noise to so bad you would swear a valve is broke off. Or a rod bearing is bad. And it can do all of this and NOT miss at all. The only way I know to check is to pull them and have them spray checked. And yes you can get a bad injector right out of the box. Two other methods of damaging injectors are. Pulling the head and leaving the injectors in, Then setting the head on a table or dragging it across the block and damaging the tips. Or damaging them installing them. Driving them in with a rubber mallet comes to mind. Hope this helps Bill

 

That sounds more logical to have a bad injector. they are stock with 201k miles on it. But that also dosnt explain why it is comming out of the air intake.

 

I've heard a few cummins make a thumping noise from the airbox. My truck did it since I bought it 4 1/2 yrs ago. It stopped when I installed a BHAF this spring. Heard friends trucks do it too. There was a thread on this a few yrs ago, some one came to a conclusion that the airbox was amplifiing intake noise or something along those lines.

 

Really. huh i took the stock air box off and replced it with a BD air intake.

 

Sorry, didn't even look at your sig to see you had an after market one. I searched airbox thump and got a few old threads to come up. some seem to think its an injector, others say its resonance in the airbox. From the a post I read, one person had the noise. took off the intake hose on the turbo and the sound was gone, thats how mine was when I had the stock airbox on it. As soon as I took off the intake hose it was gone until I reinstalled it. When I put my amsoil bhaf onit went away too. I'm not running any kind of heat shield or airbox around my bhaf, maybe thats why I don't here it.

 

Oh wow. ok so it could possibly be my intake because i have a heat sheild on mine. thanks for the help. ill work on it today and see what i come up with.

 

Hope you figure out what it is, just from my experience thats what the noise was on my truck.