[viabill]

I'm thinking about buying this '01 2500HD with Dmax/ZF6, but it has a severe shake at idle and goes into 2000RPM rev limit if you push it at highway speeds. Runs good for a while, then just shuts down and has no power until restarted.

Don't know much about it, except that the fuel filter hasn't been changed recently, and a sensor on the bottom side of the intake tube is disconnected (reconnecting it doesn't help, and according to the owner, the sensor is new). The truck seems to have good power above idle until it goes into limp-home mode (or whatever is limiting the RPM and power). It also does not smoke at idle or at speed.

Any ideas??
What do I need to check out before buying this truck?
Could the shake at idle be the Flywheel?
Would a loose reluctor cause a BAD idle, but smooth out above idle?
What is the sensor on the intake tube?

Maybe your advice is to RUN, but I would appreciate any inputs any of you guys can give.

 

[hmtstagg]

Sounds Like the flywheel is coming apart. I saw this complaint alot a few years ago. The flywheel has internal springs to dampen the clutch application instead of the springs being on the clutch disc, and the flywheels like to come apart. When they comapart they shake the truck like crazy. there is an updated flywheel that is supposed to fix this.
You obviously have to pull the trans to change it, also when the trans is out the pilot bearing needs to be changed and take a good look at the input shaft to the trans they like to wear. Good luck

 

[winter200]

sounds like what mine does when the high idle is still on. That would limit rpm - if someone put highidle on it and tried to reprogram the idle speeds it would probably act like that. You may want to look into the high idle install diy to see if you can see if it has it installed.

 

[Mackin]

The sensor is a mass air sensor and should be plugged in. Sounds like it needs a flywheel too.

There are stored codes in the ECM if you are getting ECM limp home rev limiting mode.

Start there reading the ECM.

 

[sleep rite]

im haveing the same problem gm has replaced injecters and i have replaced the fuel reg. they seem to think it may be the injecter pump i dont think they have any idea just wanting to change parts any help you could give would help alot thanks mike

 

[01Duramax6spd]

What are they asking if you don't mind saying? Where is it located . Sounds like what mind did with one of my EFI tunes . The Flywheel is definately crap I'd say.

 

[Josh2002cc]

My truck too shaked bad at idle and would not rev up past 2000 rpms. I took it to a local shop and they found out the fpr was not plugged in and when the truck demanded more power it would kick it in to a "default" type mode and would not go past 2000 rpms. Once they plugged the sensor in it ran fine. I think the sensor was on the drivers side head somewhere to the rear of the head(close to the firewall)

 

[sleep rite]

have you had any luck with the high idel iam having the same problem