LB7 rattling on decelleration

[036.6turbo]

I'm in Michigan, my brother is in Florida. He has a 130,000mi 04 LB7.

He just had the injectors replaced at a local shop. Injectors and new lines came from LDS. The truck also has a lift pump, but that is just for injector health, I do not believe he has any tuner on it at all, tune is stock.

Now he tells me if he is running 75 to 80 mph and lets off the throttle, he gets a rattling noise. Sounds like a collapsed lifter or he even mentioned a rod knock.

The shop that did the install hears the noise as well, they test drove it with him, with a scanner hooked up, all pressures are good, scanner shows nothing.

They are telling him the fuel lines get a "harmonic" cycle going at some RPMs and cause the sound he is hearing.

Anyone have anything like this happen?

I'm thinking cracked flywheel maybe?

 

[duramax on fire]

On the lly we just did with bad injectors sounded like a rod knock when you let off the throttle.

Just currious what caused the last ones to go out. Bad fuel or just old age?

Was the balance rates good at idle?

 

[036.6turbo]

On the lly we just did with bad injectors sounded like a rod knock when you let off the throttle.

Just currious what caused the last ones to go out. Bad fuel or just old age?

Was the balance rates good at idle?

Typical LB7 white haze at idle issue. I'm not sure what the balance rates were.

 

[THEFERMANATOR]

How loud is the noise? Stock tuning with good injectors at those rpm's will rattle as the timing goes way up to something like 12 degrees iirc at those rpm's at 0-10mm3 of fueling. I know mine would rattle pretty bad at close to 0 throttle above 2K rpm's, so I set my timing back down to a sane level in the decel areas, and it stopped.

 

[036.6turbo]

How loud is the noise? Stock tuning with good injectors at those rpm's will rattle as the timing goes way up to something like 12 degrees iirc at those rpm's at 0-10mm3 of fueling. I know mine would rattle pretty bad at close to 0 throttle above 2K rpm's, so I set my timing back down to a sane level in the decel areas, and it stopped.

It’s tough for me to know, how loud it is. He’s in Florida and I’m in Michigan. He described it Lille a collapsed lifter in a gas motor.

Stock tuning on a 130,000mi truck.

He did say it had the same noise, prior to the injectors being replaced, just not as bad.



Sent from my iPhone using Tapatalk

 

[THEFERMANATOR]

It’s tough for me to know, how loud it is. He’s in Florida and I’m in Michigan. He described it Lille a collapsed lifter in a gas motor.

Stock tuning on a 130,000mi truck.

He did say it had the same noise, prior to the injectors being replaced, just not as bad.



Sent from my iPhone using Tapatalk

If the noise goes away below 2K rpm's I wouldn't worry to much about it.