Hey guys, on my 05 LLY i have been having a problem for a while now. im going to use kph since im in ontario, i can drive fine with no problems or noise until i get to 100 kph, and then without even pushing the pedal at all, it sounds like the truck revs up and gets WAYYYY louder.... but RPMS dont change, and it doesnt speed me up any, i can let go of the pedal and it stops but if i push it again, it will make the same noise. But if i lower my speeds below 100 again, like 90, it wont do it at all.

I know for a fact that it cannot be injectors because i just had them done by SoCal, and the truck was doing it before the injectors were done as well. and now its still doing it. let me know what you guys think. i really need help, its getting annoying.

If it sounds like a valve rattle, it may be the pilot injection turning off. Mine does this, I think it is more related to rpm and power requirement. If I set the cruise at say 58 (ish) it will do it, but not at 60. Could also be time for the ice pick. Before the Ice Pick, I could tell you when it was going to do it based on standard driving pattern. Pull out, accelerate to 60 mph, and it would sound like the valves were rattling, hit the brakes, stops the noise, turn, get back on it to 55 mph no noise. Make next turn, get to 60 - 65 rattle again. I knew the pattern, I could be on the freeway, and tell you when I passed through a set speed / rpm that it was getting ready to make a noise. Usually sounded like it was coming from the passenger floorboard.

Oh, and by the way mine did it worse just before the #7 injector lost connection.

how can i check my balance rates when im driving with EFI live?
Because it definitely does sound like its from the floor behind me on the passenger side

bump!!!!

Your description of your truck getting WAY loud with no RPM increase sounds like your fan is kicking in but it's hard to determine what the sound is if I can hear it.

definitely not a fan, bu ti will try and take a video with sound tomorrow

ive tried everything guys, the sound just doesnt pick this noise up at all... if i let off the pedal it stops, if i hammer on it, it stops, but if im just cruising a constant speed, its there... is it possible it could be the Fuel pressure regulator valve? would that cause a surge type thing?

Your talking ground speed, so what gear are you in?
RPM would be more helpful.
In 5th will it run over 2000 RPM. If still in 4th, maybe pilot injection adjusting. In 3rd you are at the governor or over.

i checked today.. it happens between 100km/h(60 mph) and 120 km/h. and the RPM's are from 1800-2000 . the noise sounds like its coming from behind the passenger rear seat.. maybe the banks monster muffler is gone? im not sure..

Ok solved the problem today. I tried everything, and couldnt figure it out. i just happen to be changing my differential fluid an dnoticed that my rear U bolts holding my axle onto my leaf springs were loose>>>> Very Loose. I took them off and put anti sieze on them and re-installed them and the noise disappeared for the rest of the day so far .. Thank god