2007 Hummer H3

Shakes or Wobbles problem
2007 Hummer H3 All Wheel Drive Automatic 36000 miles

I have a 2007 Hummer H3 with 36000 miles on it. When the motor is running around 1500 RPM there is a really bad vibration throughout the vehicle. As you move up through the RPM range the vibration goes away. Everything else feels fine, the truck still accelerates the same and doesnt seem to have any loss of power. Any ideas would be appreciated.
January 12, 2009.

Is it a vibration when driving?At high speeds?Low speeds?When taking off?In 4wd?The whole vehicle?Front end?Rear end?Could be a number of things. Before diagnosing I would call the dealer and tell them you have 36,000 on it but have a vibration problem and the dealer might goodwill the repair, most dealers are pretty fair about goodwilling vehicles that are just out of warranty.I would call them first they might help you out at no cost to you. If they do not help post back and I will help as best I can.

Brian 1
Jan 12, 2009.
It does it whenever the motor is running at low RPM's even when the vehicle is in park in the garage. That kind of leans me toward it being an engine issue. I can feel the vibration throughout the whole vehicle but the gas pedal and the steering wheel are probably the worst areas for transmitting it.

I try to avoid the dealership whenever I can because they are a pain in the butt to deal with. They are about 45 minutes away and wont even give any ideas about what could be the issue until you are sitting in the dealership after taking time off work to get to them.

Any ideas you may have would be great.

Jan 12, 2009.
Only help I can give is, check the engine compartment for any p/s lines making contact with the firewall or any lines making contact with the engine, this will cause a vibration. If so move the lines out of the way and see if it goes away. If not could be alot of things, like an internal engine vibration which could be crankshaft out of balance, could be a alt, p/s or harmonic balancer out of round. Could be an engine/trans mount loose of moving. You did not say if this vibration is happening when the vehicle is moving.I" m sorry but I can only advise so much, I" m not there to see the vehicle, vibrations are very hard to diagnose. If all else fails for a fix the only other thing is putting on the eva, which is the electronic vibration analizer which is a hand held tool that only the dealer has, but this tool will find the source of the vibration. I have used this tool before and it does work, only problem dealer are the only ones with access to it. Try the above suggestions and post back with what you find and will advise from there.

Brian 1
Jan 12, 2009.
A few things come to mind in an effort to diagnose. Remove the drive belt, that would eliminate the accessories, and run the engine up to see if vibration persists. Not too long, don't want an overheat or dead battery. The next thing would be to disconnect the torque converter and run the engine up again. The latter is easier said then done, it is pretty tight. A thin, long, 0 offset box wrench is about the only tool that accomplishes this aside from removing the starter(which isn't fun either). I assume that there is no check engine light on, a misfire would cause a vibration but would also trigger the light.

Jan 29, 2009.