LLY: Weird knock at heavy throttle.
- Thread starter PAT
- Start date
Well it rattles a little, i dont think its as bad as a 7.3 but i have never heard what "excessive" rattle sounds like so its a little hard to tell i guess
Definitely louder after 2500, its hard to tell under hard acceleration as the turbo and exhaust drown it out
Well I am now concerned about this. The truck was tuned at guy tripps shop. I don't know what the timing and pulse width are. So maybe he can help out. Also, I am going to try to take a video to see if I you guys can pick up the sound. I have to get the truck re tuned Anyways. So If it's something weird in the tune, then hopefully I can get it fixed. Thanks for the help Dan and pat. Hopefully kspen and myself can get this fixed!
It's very noticeable. Like I said, I'll try to get a video up.
Truck never did it when I had a stock charger for some reason. And it's doing it under 2500 RPM. I will talk to guy and see what he thinks since he had it tuned. And get the video so everyone can hear what I'm talking about.
I dont live in Socal anymore. So if it's something in the tune. Hopefully I can get some help getting it worked out.
Truck never did it when I had a stock charger for some reason. And it's doing it under 2500 RPM. I will talk to guy and see what he thinks since he had it tuned. And get the video so everyone can hear what I'm talking about.
I dont live in Socal anymore. So if it's something in the tune. Hopefully I can get some help getting it worked out.
Mine kinda just sounds like a diesel, as dumb as that sounds but on the other hand my paranoia kicks in and i think thats not normal.....im interested to hear your video, i tried to take one of mine but all i have at the moment is my phone and the sound was terrible. Ill try with a camera tomorrow
It is totally timing rattle/ too much fuel. the reason you did not hear with the stock charger is because you built boost earlier. Burned the fuel up, Now that you have turbo lag the injection and timing tables are off. you need to get re tuned and be-careful driving around. I had this problem for a few days when i was building a mileage tune. I had to much timing with the wrong pulse width. She is all good now and getting 17-18 mpg mixed.
Ok fellas. I tried to make a video but all I have right now is an iPhone and the audio is kinda sketchy. However, I got on YouTube and found a truck that makes a similar noise. Listen closely and you can hear a knocking at 7sec that doesn't sound like normal diesel engine rattle. This is what mine sounds like. Then clears up after about a second or two when the turbo spools.
http://m.youtube.com/index?desktop_uri=/&gl=US#/watch?v=oHe4R-N7Qz8
http://m.youtube.com/index?desktop_uri=/&gl=US#/watch?v=oHe4R-N7Qz8
http://m.youtube.com/index?desktop_uri=/&gl=US#/watch?v=oHe4R-N7Qz8
I'm on my phone. So hope it works. If not, search "duramax rolling burnout" on YouTube. It's the one that you can see his sideview mirror. Trucks an LMM.
I'm on my phone. So hope it works. If not, search "duramax rolling burnout" on YouTube. It's the one that you can see his sideview mirror. Trucks an LMM.
yes that is injector rattle...
here is the video if anyone else wants to see it.. http://youtu.be/oHe4R-N7Qz8
[YOUTUBE]http://youtu.be/oHe4R-N7Qz8[/YOUTUBE]
here is the video if anyone else wants to see it.. http://youtu.be/oHe4R-N7Qz8
[YOUTUBE]http://youtu.be/oHe4R-N7Qz8[/YOUTUBE]
Mine sounds a little louder than his. But then again, it's a different motor.
So why is it louder before the turbo lights Dan? Is it just because te fuel isn't burning completely yet? Like Joe is saying?
So why is it louder before the turbo lights Dan? Is it just because te fuel isn't burning completely yet? Like Joe is saying?
In part yes.... As engine rpms increase the engine needs more timing to burn the fuel at the optimum time (crank rotation deg), Less rpm requires less timing/fuel. So again too much fuel (no boost to burn it) being dumped in too soon (timing)= timing/injector rattle..
By the way my personal truck had a 80mm inducer/108mm exducer (GTX4508R, Very large single) single charger on it and has NO injector rattle no matter what RPM or throttle position I’m at. With proper setup/tuning it can be eliminated..
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I hate to use this as an example but you can clearly hear it in this video before the engine gives up. This is what injector/timing rattle sounds like, However much more server with nitrous. This was done with too much nitrous too soon. Similar sound but it won’t be as loud without the nitrous..
sorry for using this video as an example
http://youtu.be/5perV0v6lkk
sorry for using this video as an example
http://youtu.be/5perV0v6lkk
Ok. Well thank you for all the help Dan. I will get the truck retuned here soon. Hopefully I will be able to work that out.