LBZ: Vibrations At Idle

[c20elephant]

Don't see how it won't fit. You don't have a differential to get in the way of things.

Your just efing with me.....
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[c20elephant]

600 is the stock idle speed for 01, so why is it bad? GM changed it because of the nasty harmonics you encounter in the 640-650 range. Mine is still at 600, and is fine, but you do notice the harmonics just off idle. As to polymounts, they're going to give you more vibrations at idle, just thenature of the beast. And the ladt thing in the world one would want to do is use the engine block to stiffen the frame. The engine is already under extreme forces justfrom running, let alone if you add more to it. Poly mounts stiffen things up, yes, but it comes at a cost. I'll never run them again.

I don't do burnouts or abuse the truck like a lot guys, I use it but do not abuse it and the mounts did what I intended them do....:thumb:
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[TheBac]

600 is the stock idle speed for 01, so why is it bad? GM changed it because of the nasty harmonics you encounter in the 640-650 range. Mine is still at 600, and is fine, but you do notice the harmonics just off idle. As to polymounts, they're going to give you more vibrations at idle, just thenature of the beast. And the ladt thing in the world one would want to do is use the engine block to stiffen the frame. The engine is already under extreme forces justfrom running, let alone if you add more to it. Poly mounts stiffen things up, yes, but it comes at a cost. I'll never run them again.

Just MO, but the lower idle + polymounts isnt the best idea on a DD truck. The vibration got worse throughout the cab. Put the stock tune with higher base idle back in and the excessive vibration is gone. Maybe it was the motor build, maybe the tune...I just know its fixed.

 

[THEFERMANATOR]

The problem I have with the lower idle, is you have to go through that 640-650 range where the harmonics are severe. I prefer mine idling at 600 myself, just like the lower idle, and the decreased load on my brakes.

 

[c20elephant]

]Just MO, but the lower idle + polymounts isnt the best idea on a DD truck[/B]. The vibration got worse throughout the cab. Put the stock tune with higher base idle back in and the excessive vibration is gone. Maybe it was the motor build, maybe the tune...I just know its fixed.

Why not.?

Question for ya'll, would anyone keep the stock engine mounts and use a poly mount at the transmission.?

 

[TheBac]

Why not what, Mike? Mine reacted that way. If yours didnt, then completely disregard my bitching. Every truck is different.

 

[c20elephant]

Why not run poly mounts on a DD was the question, it did not highlight the first time..:thumb:

 

[c20elephant]

Open the scan tool, connect to your vehicle with the little green button icon on the left. Once connected, there are tabs along the top of the screen. Look for the one that says DVT. Click that tab and it will open the DVT tool options. Look for the button towards the upper right of that screen that says activate. Click it. There is another tab on the left side of the screen that says "control". Click it. One option will be idle speed. Check the box next to it and slide the bar back and forth to turn it up or down.

Next question, can the truck be driven temporarily with the laptop and V2 hooked up till I find what idle works best.?

 

[WolfLMM]

Umm I don't think so, not with the dvt controls active. Well least on my truck, when you touch the brake pedal it disables whatever function you were controlling. Does this happen to anyone else?

 

[Dozerboy]

I think so

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[Harbin_22]

I think it shuts off. Test it out. Not going to hurt anything.

 

[c20elephant]

Thanks, I read the PDF couple years back and IIRC the DVT does dis-connect if you push the brake pedal. If it did not you could do some serious damage to the transmission or engine if you hit the wrong button while driving if the DVT was active.

 

[THEFERMANATOR]

Try it and see. I know not all the dvts quit as I had an issue before where the ac wasnt being triggered, so i turned it on vie the dvt, and it worked. I've also used it to tune out drone with the vvt side. Adjust the vein position going down the road until it gets to where the drone goes away so I know which way togo in the tune file to get rid of it.

 

[c20elephant]

Thanks Ferman, I had it hooked up about 2 years ago and it was a little cumbersome to get it connected, either try it or peruse through the 2 PDF's the Tuning Tool User Manual at 107 pages or the Scan Tool User Manual at 195 pages has to be in their somewhere...

 

[WVRigrat05]

My LMM vibrates like hell, not rattles at the rpm it's set at. I'm going to run those mounts you sent me with bolts just because the ma's are a waste for my set up that and I don't want the rattles of a stock engine you get with them.

You'll probly have to idle around 700 or over 730 to get it right

 

[c20elephant]

Can you do this with a locked autocal efi download?

https://www.efilive.com/product-info-efilive-scan-tool

http://www.duramaxdiesels.com/forum/showthread.php?t=27243&page=5

 

[Awenta]

Mines idles around 690. Nice and smooth

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[Harbin_22]

Put an AF cam in with a balanced rotating assembly and all your idle vibes will go away. I hated MA mounts until this ngine. MA mounts and poly trans mount and she's smooth t stock idle.

 

[c20elephant]

Put an AF c in with a balanced rotating assembly and all your idle vibes will go away. I hated MA mounts until this ngine. MA mounts and poly trans mount and she's smooth t stock idle.

If this motor ever grenades I'm buying a 1970-1972 Fleetside Shortbed Chevy P/S, P/B, A/C that someone has already done all the work. The last years just before emissions started to get nasty in 1973 and has front disk brakes, rear drums to disk are an easy bolt on application if not done already....:thumb:

FWIW I had rattles before the Merchant Mounts now just in a different spot. I'll treat it like a cricket and find it, and it could be the exhaust pipe hitting the torsion bar mount again....:woott:

 

[c20elephant]

AAAAAAaaaaahhhhh quiet, the 720rpm tune is much better, but, the transmission seems a bit quirky and I'll give it a few days and maybe drop it to a 710 idle. The DVT controls do not disconnect and drove the truck around for few minutes with the laptop connected.

Had a hell of time loading the new calibration into the V2, after about 4 times getting an error, reading PDF files, watching youtube videos I took a closer look and SD card and it was not locked in.....:doh:

Can anyone think of reason a 720rpm tune IS not OK in the LBZ, I know the LMM has a stock 720 rpm idle but it also has no speed sensor at transmission bell housing like the older models.?

Thanks all, now have to go see if can get my Brother-in-law's Torchmate table operational.............:thumb: