Just picked up a 93' Accord with 2.2 (125 hp) auto and the engine vibrates at idle while in gear. The problem decreases in park or neutral, but gets pretty bad when the AC compressor engages. All the vacuum lines seem intact and the motor mounts seem okay. Any ideas?? Thanks.

 

I'm not sure if this can help but I had the same problem with my civic. Everytime my car would sit at idle I could hear this loud vibration. Ended up being the hood latch that had some free play in it causing some vibration. I replaced the hood latch and the vibration went away. Hope this helps.

:canada:

 

Okay, I tried to live with it and I can't. I have replaced all motor mounts except the rear. I understand this rear motor mount has some sort of vacuum line to control the motor mount. In checking this out, I found a control mounted to the firewall that sent vacuum to a module that appeared to be connected near this motor mount. The control had an electrical connection and an adjustable knob. (tried the knob and did nothing.) Is this for real and how does this work? Any help would be greatly appreciated cause I can't stand the shake NO MO!!

 

I would check engine compression - if you have one cylinder that isn't doing the same work as the others, you will get some vibration - if all the cylinders are within 15 percent of each other, then I would suspect a broken piston skirt or a bent connecting rod - could also be the torque converter in your tranny.

 

I would check engine compression - if you have one cylinder that isn't doing the same work as the others, you will get some vibration - if all the cylinders are within 15 percent of each other, then I would suspect a broken piston skirt or a bent connecting rod - could also be the torque converter in your tranny. If I'm not mistaken your accord engine has a balance shaft in it, which could be out of time as well causing vibration. All this is assuming that you've already tuned up the engine (plugs,wires, cap rotor, etc.) I would also check your egr valve, it might be stuck open - CEL ?

 

I don't think it's internal because the vibration goes away right off idle. I would think an internal balance problem would increase with RPM. I have done the full tune-up and replaced the all motor mounts except the rear, which I still think may be the issue. I've just never seen a vacuum controlled motor mount. Thanks.

 

I'm really curious about this one - I'll get back to you... need to do some research