2002 gmc envoy_slt
New guy here. This forum is awesome. I am fighting the same vibrations as many before me. Mine shakes the grill at idle but seems to go away as RPMs increase, however my rearview mirror shows a vibration at highway speeds and I can feel it in the steering wheel. So far- new motor mounts, new plugs/wires, new alternator and new coils. I have no codes. I have a 2002 Envoy w/ 150k but extremely well maintained and clean. A scan shows nothing wrong with the engine or transmission, compression test is great. My belt tensioner seems to bounce/vibrate a bit so that will probably be my next part to change.