ok guys, and gals, this is my second post. I have a LB7 01 gmc that while 3/4 to full throttle past 2500 rpm or so my truck is making a sound that scares me.It sounds like a sick typewriter, a clatter/chatter sound. It does it as described every time I put my foot in it. I can't really tell if its a mechanical sound like a bearing but I don't suspect it is. once the turbo spools and it starts making big power it does it from 1st gear up. It is at its worse right before it shifts. (Allison trans) When it makes the sound it still has the same power and nothing else funny happens only the noise. no power loss or surging just a crazy sound. Ive never owned a dmax only peterbilts with cats, detroits and cummins. never heard this before. it sounds like its coming from the right side of the engine. Its not terribly loud just sounds bad to me. when it starts to make the sound as the rpms increase so does the sound and the frequency or the chatter. when it shifts and rpms drop, no sound. then as boost builts it repeats until it shifts. Ive searched all over this forum and the closest thing Ive found is pilot injection off? ON? Im learning here so be easy on me. thanks in advance.
WOT clatter, typewriter sound, something? help
- Thread starter tommywalton1974
- Start date
oh I forgot to mention, It doesn't seem to do it as bad with the ac off. but i cant see how it could be related to the clutch on the compressor. Im sure its not, maybe im crazy and it is just as bad with ac off.
There is a decent chance you are just hearing engine with the pilot injection off.
I have noticed that my engine is a lot louder with the stock tune than with my current tune. What tune are you running, or are you stock?
You can try and find someone nearby with a duramax to ride along and see if it sounds normal, or get a video and post it here.
I have noticed that my engine is a lot louder with the stock tune than with my current tune. What tune are you running, or are you stock?
You can try and find someone nearby with a duramax to ride along and see if it sounds normal, or get a video and post it here.
Yes stock as far as I know. What is pilot injection? Why is it off? Is there a wiki on here? Also it does it at half throttle. When it hits 2500 it sounds like the rod bearings fell out 