I have a 96 blazer that has a heavy vibration when idling in drive, especially with the A/C on. I have changed the EGR valve, plugs and wires. Any ideas of what this can be? Reverse is fine, nuetral is fine, park is fine. Only the drive gears make the engine vibrate at stop signs and stop lights. Worse with the A/C on. Thank you in advance for any information.

 

If its not doing it in any other gear , have you had your tarnsmission checked yet? I wonder if it could be the lock up in the torque converter.. If you put it in drive and start to power brake it what happens? you know what power braking is right? ive actually had people stare at me like i had three heads when i said that to them..like a deer in the headlights..

 

it is worse with the A/C on. Not sure if this is transmission related.