i have a 88 blazer 5.7 tbi ,700r4 trany . i noticed some noise under the truck , sounds like its comming from the torque coverter , i pulled the inspection plate and noticed my flywheel has a wobble to it , the truck runs pretty good but lacks power , could this noise get picked up by the knock sensor and retard my timing ? also what else could be making that noise? torque converter,flywheel, trany pump ? torque converter bolts r tight , the flywheel wobbles but not the converter, any help or ideas would b helpfull thanx

 

Could be a warped or cracked flex plate. A noise from the flex plate could be picked up by the knock sensors.

 

i would start with a flywheel i dont think there supposed to wobble

 

No they're not. Also check for loose bolts and oblong holes if the bolts are loose as well as the aforementioned cracks. Had a 82 2WD truck with this problem.