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Weird sound when I start my truck cold following delete.

6322 Views 19 Replies 10 Participants Last post by  Norm12, 
C
After replacing the exhaust, loading my tune, and unplugging EGR, I have the following sound out of the exhaust when I start my truck in the morning, cold. When it's warm, it does not make this sound. Flo-Pro down tube back exhaust with a 30" FTE resonator placed behind the straight pipe out of the down tube. I hosted the sound on my soundcloud account - https://soundcloud.com/drummin_man44/truck-bus-saw. Any thoughts why it sounds like a table saw?
By the way, the truck is 100% better after the delete. I will be pulling the EGR off this weekend.
Thanks
Chris
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B
Yea Table saw is good description, never heard a truck like that before. Got get your stethoscope out. Listen to things turning very fast, Turbo, Alternator, other pullies, Trani input and TC. Sounds a lot faster than engine rpm alone.
Load on alt may le tup from charge after start. Turbo blade or bearing. may be , pull hose and listen.
Maybe a boost, exhaust or other leak after delete.
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sthrnromr
Can you verify that your exhaust brake is OFF when starting truck? If it's on, try starting it with it off.
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C
It's not under the hood, only through the exhaust. Would those other items come through?
Chris

bigfish95971 said:
Yea Table saw is good description, never heard a truck like that before. Got get your stethoscope out. Listen to things turning very fast, Turbo, Alternator, other pullies, Trani input and TC. Sounds a lot faster than engine rpm alone.
Load on alt may le tup from charge after start. Turbo blade or bearing. may be , pull hose and listen.
Maybe a boost, exhaust or other leak after delete.
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sthrnromr said:
Can you verify that your exhaust brake is OFF when starting truck? If it's on, try starting it with it off.
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This, and make sure it’s not on High Idle either. Mine sounds more like a jet when it’s in high idle, but close enough to that table saw sound you linked that I can hear a similarity.

FWIW, I would double check everything on the exhaust to make sure it’s not touching anything it’s not supposed to. The jet sound is normal for a high idle, I almost wonder if the whine of your table saw is caused by a slight vibration somewhere along the pipe.

BTW, you nailed it with the description of a table saw, I wasn’t expecting the sound clip to sound like that but I’ll be damned :hehe:
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C
Yeah, I need to check the torque on the bolts, but it went in really clean, Nothing was touching anything. At first I thought I put the resonator in backwards or something. I was hoping someone heard this and recognized the sound. I'm going to check the position of the turbo vanes when I start it warm and compare that tomorrow when I start it up.

HFolb23 said:
BTW, you nailed it with the description of a table saw, I wasn’t expecting the sound clip to sound like that but I’ll be damned :hehe:
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sthrnromr
Can you try starting it with exhaust brake off and with exhaust brake on and see if there is a difference. Try both when cold.
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Andy2500
Watch the VGT % position if you are able to in the EZ lynk app to get an idea. Mine does a very fast 85-90% flutter for a short period on all start ups, but that is sounding a lot slower and more deliberate than what mine does. Little bit of a turbo surge is normal on start up, but that sounds a little strange.
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C
I was watching the turbo speed this morning, and noticed that when first started, it sat at 8,000RPM. You could hear the whine. If I turned the exhaust brake on, the turbo spooled up to 12K, then back down to 8. When it hit 12K, no noise. On it's way back down to 8k, it started to whistle, and then oscillate a bit. Once warmed up, it was at 18K RPM at idle. I'll check the VGT position tomorrow. I forgot about that today.
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J
I don’t know what everyone else is hearing, but to me, it literally sounds like someone is cutting a piece of plywood with a circular saw next to a running diesel truck. Now, I know exactly what a deleted truck sounds like on a cold day at startup with the exhaust break on, and it doesn’t sound anything like that.
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Deltron
Probably totally unrelated but I had a Buick Grand National that made a similar sound on cold start too. I replaced the turbo a few days later. :(
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m_ross05
Yea i wonder if it is blades on either side of the turbo contacting the housing/vanes.
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N
Hey Chris, you ever figure out the table saw noise. I just deleted my 18 2500 the exact same way as you did and have the same exact noise.
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C
Hi Norm,
It was the tune. After going through everything I went through to get it resolved, I sent another note to the tuner and asked if he had any ideas. He said he had programmed it in as a "feature" for his tunes. Apparently he had never been in a campground leaving at 6:00 AM and trying not to wake up your neighbors with your table saw exhaust note. Had I known that before hand, I never would have purchased the tune from him. Try reaching out to your tuner and ask them. Send them my sound file if you need to.
Chris
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U
No muffler equals lots of turbo noise and when the vanes are closed it's even louder!
Put a muffler on it! Tunes won't change it. A muffler will help a lot.
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URDiesel said:
No muffler equals lots of turbo noise and when the vanes are closed it's even louder!
Put a muffler on it! Tunes won't change it. A muffler will help a lot.
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I have a muffler on it just like Chris, it's the tune when the exhaust brake is on.

Sent from my SM-S908U1 using Tapatalk
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chris t said:
Hi Norm,
It was the tune. After going through everything I went through to get it resolved, I sent another note to the tuner and asked if he had any ideas. He said he had programmed it in as a "feature" for his tunes. Apparently he had never been in a campground leaving at 6:00 AM and trying not to wake up your neighbors with your table saw exhaust note. Had I known that before hand, I never would have purchased the tune from him. Try reaching out to your tuner and ask them. Send them my sound file if you need to.
Chris
Click to expand...
WTF??? Who wants the truck to sound like a buzzsaw taking off for the moon? I appreciate it. I realized that it doesn't make that sound when the exhaust brame is off, but who wants to remember to turn off the exhaust brake before starting a truck remotely just to turn it back on when driving to avoid that sound...

You didn't happen to lose connection with the ECM/PCM once in a while for no reason at all did you? I also can't seem to clear my codes and get transmission pressure low code sometimes even though it regularly hovers around 170. Also wondering how we can get it to read EGTs & and barometric pressure, mine both stay static. If I ever get them to answer on the phone I just want to have all my questions answered.

Sent from my SM-S908U1 using Tapatalk
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Norm12 said:
WTF??? Who wants the truck to sound like a buzzsaw taking off for the moon? I appreciate it. I realized that it doesn't make that sound when the exhaust brame is off, but who wants to remember to turn off the exhaust brake before starting a truck remotely just to turn it back on when driving to avoid that sound...

You didn't happen to lose connection with the ECM/PCM once in a while for no reason at all did you? I also can't seem to clear my codes and get transmission pressure low code sometimes even though it regularly hovers around 170. Also wondering how we can get it to read EGTs & and barometric pressure, mine both stay static. If I ever get them to answer on the phone I just want to have all my questions answered.

Sent from my SM-S908U1 using Tapatalk
Click to expand...
Are they still in business ? Most have closed shop!
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Norm12 said:
I have a muffler on it just like Chris, it's the tune when the exhaust brake is on.

Sent from my SM-S908U1 using Tapatalk
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I leave my exhaust brake on 100% with a 4 inch exhaust and muffler. It never gets that loud!
You can only hear the Turbo when the high idle is active.
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URDiesel said:
Are they still in business ? Most have closed shop!
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Ya they picked up the other day finally, but I lost service. I've got a rep as well that I can reach out to... the guy who sold me the ezlynk
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