My navigator 04 vibrates at low speed and idle?

Idle speed may be too low. This is usually caused by a leak in the vacuum system, dirty air filter, bad or contaminated fuel, or computer failure.

Hi, you could check your engine mounts.

which engine.??? never post lacking engine ,here is why.
1.3 L G13B I4
1.5 L G15A I4
1.6 L G16B I4
1.8 L J18A I4
1.8 L BP-ZE I4
1.9 L XUD9 diesel I4

Ill answer in the generic and for GAS engines. only.
that is illegal RPM, the ECU regulates it to 800 all the time
that means the ECU can not regulate the RPM now, for many reasons.
and sure it vibrates too low, that is normal for all 4cylinders to do that.
no bad engine mounts never lower RPM to 600, ever.
they dont control idle speed at all.
the #1 reason for most cars to idle too low are:
1: EGR leaks, (clean it)
2: ISC stuck closed (electric idle speed acututor dirty) clean it.
3: gross misfiring , caused by bad spark or bad fuel mix.
4: low compression on 1 or more cylinders (real low) Do compression test at WOT. throttle.

Wow thats a bunch of miles for only 9 yrs.
I would want to know if it is something related to the engine or transmission, or the wheels and suspension.
Does it happen in all gears, and at any road speed ? Can you rev up the engine and make the vibration, or does the car have to be moving ?

Hello! This is a known problem that is addressed by the following Technical Service Bulletin...Guru...saailer

Subject:Steering System Moan, Groan, Shudder and/or Vibration Type Noise During Low Speed Turning Maneuvers (Replace Steering Gear) #04-02-32-007A - (12/01/2004) Models:2004-2005 Buick Rainier
2003-2005 Chevrolet TrailBlazer, TrailBlazer EXT
2003-2005 GMC Envoy, Envoy XL
2004-2005 GMC Envoy XUV
2003-2004 Oldsmobile Bravada
Short Wheelbase Utilities Built Prior to VIN Breakpoint 52123375
Long Wheelbase Utilities Built Prior to VIN Breakpoint 56137280
This bulletin is being revised to remove the 2002 model year and add the long wheelbase utilities. Please discard Corporate Bulletin Number 04-02-32-007 (Section 02 -- Steering).

ConditionSome customers may comment on a moan, groan, shudder and/or vibration noise while making low speed turning maneuvers. Customers usually notice this condition in parking lot turning maneuvers.
Correction

1. Diagnose the power steering concern. Refer to Symptoms - Power Steering System (SI Document ID #670351).
2. Replace the steering gear with a newly designed steering gear. See the parts information below. Refer to Power Steering Gear Replacement (SI Document ID #742314).

Parts Information

Part Number

Description

Qty
88965356
Gear Kit, Steering
(Short Wheelbase Utilities)
1
88967181
Gear Kit, Steering
(Long Wheelbase Utilities)
1
Warranty InformationFor vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time
E9740
Gear Assembly, Power Steering - Replace
Use published labor operation time
E2000
Toe, Front - Adjust

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

does it vibrate at highway speeds or sitting still at idle? the highway speed vibration could be tires out of balance. the idle speed vibration could be weak engine mount or idle speed too low.

I don't know how much oil you had to put in but it sounds like you have maybe more than opne issue and both sound major. One is engine reving and speed not picking up sounds like trans problem. Two the engine shaking and making noise and being run low on oil leans toward possible engine damage. If your mechanicly inclined check all fluids and when checking trans fluid smell it. If it smells burnt the trans has been damaged. Check oil pressure and make sure coolant is full.You may have to take it into the shop.

I have encountered this problem also, try changing your battery. My battery lasted almost 4 year till it was the cause the shot my alternator.

raise your idle speed just enough to stop the rattling