help! Vibration when driving
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Intermediate
Joined: Mar 2016
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From: Jupiter Florida
help! Vibration when driving
Hey guys I need some help on this. My car recently, a 2000 ls1 corvette a4 (4l60e), has been vibrating or shuddering or i dont even know. But at 45-55, I think when its in 4th gear just cruising, I will press on the pedal barely, maybe like 20-25%, and right before it is about to downshift, the whole care will start to shake, mostly the back of the car, as if I'm running over bumps in the road. I have no idea what this could be. Any advice is needed!
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Hmmmm,,, I would start at the rear of the car. Chock the wheels, set the parking brake. Have an assistant start the engine and apply the brakes. Put the car in DRIVE. While you are looking under the car at the rear drive train components: (CV Joints, A Arm Bushings, differential. strut rods, wheel bearings/hub assys... ect,, rev/power brake the engine and TORQUE the drivetrain.
Look for any lost motion, wrapping of components, flexing ect.
Have them torque and let off the power several times to see if there are any worn, loose, damaged suspension/drive train components.
You also need to jack up the rear of the car and check both rear wheel HUBS for damaged bearings. Push/pull each wheel at the 000-108 & 90-270 deg location and see if the HUB assy bearings are loose. A good HUB bearing will have little to no lost motion/play.
You could also have a damaged TT rubber coupler so you will want to examine the TT for any noises or damage to the outer tube housing.
Bill
Bill
Look for any lost motion, wrapping of components, flexing ect.
Have them torque and let off the power several times to see if there are any worn, loose, damaged suspension/drive train components.
You also need to jack up the rear of the car and check both rear wheel HUBS for damaged bearings. Push/pull each wheel at the 000-108 & 90-270 deg location and see if the HUB assy bearings are loose. A good HUB bearing will have little to no lost motion/play.
You could also have a damaged TT rubber coupler so you will want to examine the TT for any noises or damage to the outer tube housing.
Bill
Bill
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
LOL!!! Well I guess you have discovered that the LS1 does NOT like a misfire!! I blew off ONE spark plug wire while I was at WOT around 6000 RPM. I thought I blew the engine. 
One of the clues that should have told you it was a misfire was, the CHECK ENGINE LIGHT (CEL). It would have been FLASHING during the misfire event.
Glad it was that easy.
BC
One of the clues that should have told you it was a misfire was, the CHECK ENGINE LIGHT (CEL). It would have been FLASHING during the misfire event. Glad it was that easy.
BC
