Accerlation sputter loud noise ARD HEAD?

Correction, Engine serial is SDP05088.

 

Yup, 600/2050 1200rpm.

That's the noise I am hearing! The valves are very loud, (stuck open if that is correctly coined), rachity, just extrememly noisy staying open for just a moment. It makes a hell of a racket! Then it is as though something releases them and instantaneously it is quiet as it progresses through the rpms. Sometimes it will repeat within a split second where i can feel it. Example, I will accelerate, the noise will start, pause, then start again then stop all the while I am increasing in RPM without releasing the accelerator. I don't understand why?

So, if the VVA is bad or worn, will this likely cause my issue? He was monitoring what he called the CGI Gate which appeared to open and close along with every slight movement I would make on the accelerator. He said it was perfect. Not sure if actually performed an ASVT in full?

The cgi flapper has not been checked or I don't think he did? He did not open up anyting. When you mention slack in the flapper, what is the symptom of this? What exactly will occurre if there is slack in the flapper? This too sounds like what I've been describing.... "as though a gate or something is wide open causing all sorts of valve noise then it gets slammed shut and all is quiet as the rpm's increase. They did not check this assuming it requires opening up the turbo?

Would engine temperature differences likely to cause the VVA or the Flapper to be sticky? What would be a symptom of a sticky VVA? If there is slack in the Flapper, what would be a symptom? If the slack is there, would it not act up all the time regardless of engine temp? I am no mechanic, however if given to me in a mechanics laguage, perhaps a little english too haha, perhaps i can convince these guys to look deeper. The problem is everyone just looks on the surface and will not keep digging until they find the issue. I know I am not the only one who's had this happen.

What is time frame to replace VVA assembly or the CGI Flapper? The fact it won't do it everytime tells me something is wrong and it is not "normal".

 

Thanks for the reply. I just purchased the truck and I am the third owner. The ESC was transfered a couple days ago. Friday, Caterpillar replaced something in the lines of a check valve on the right hand side of the engine next to the head, in the area of a fuel line or some such. They also installed a program update, but am not sure what update? The transfer of ESC was just done on Friday as well as the update so it may not show up in the system as of yet? Thanks again for the info.

 

Yup, that's who did the work, assuming this is the update they did? As for my other issues, how can I get them to acknowledge them?

 

EDIT!!!!! Thanks for the tip. If a stud is broken, would this produce the VVA noise at random or wouldn't it produce every time? What about the IVA? If the valves are opening too quick, then staying open as though they are sticking or stuck, this too could be a sign of broken studs correct? Also, there is said to be a retro-fit that CAT has which changes the 3/8" stud to a 1/2". This true or false?

 

Do I understand this correctly: The CGI valve flapper in the intake pipe to the turbo may have too much slack thus causing a noticeable idle pulse. As for my loud valves, I may have a sticking VVA assembly which is a sign of it being worn or damaged. Or, I may have broken studs in the VVA?. Or I have may have all three hardware failures? Please explain if I am wrong or right as it all sounds relative and thus cannot function without one or the other?