Can't tell what's wrong.. Engine is very shaky (not a mount thing)

[FishyMan]

So, my uncle's car has this problem.

When the car starts, the car has a pretty rough shake during idle. It's not something you'd feel from a bad motor mount. The car DOESN'T die out, but it has a shake especially after a full warm up. When accelerating, you feel the shake slightly, but it doesn't go away.

I looked at the plug wires and no oil. Could it be bad plugs (was changed before) that's causing this? Is this a case of misfiring? No CEL on the car though.

It doesn't really have this misfire pattern that you might feel, rather it just sounds like some belt, or something is causing the car's engine to shake.

Thanks.

[ChIoVnIdCa]

So, my uncle's car has this problem.

When the car starts, the car has a pretty rough shake during idle. It's not something you'd feel from a bad motor mount. The car DOESN'T die out, but it has a shake especially after a full warm up. When accelerating, you feel the shake slightly, but it doesn't go away.

I looked at the plug wires and no oil. Could it be bad plugs (was changed before) that's causing this? Is this a case of misfiring? No CEL on the car though.

It doesn't really have this misfire pattern that you might feel, rather it just sounds like some belt, or something is causing the car's engine to shake.

Thanks.

Could be alot of things.. What does it idle at? When I had that problem there was an issue with my map sensor

[blackice]

have you checked timing?

[shern]

I'm resurrecting this thread.

I'm having very similar concerns with my 1991 EX with 187k miles. Here are the symptons:

1) When the car is in gear, I have very intense vibrations and reverberations throughout the car. The idle does not fluctuate, it's very steady and acceleration is perfect when I take off. It feels mechanical in nature like a mount, but the car does not jerk when putting into gear or accelerating.

2) When the car is in neutral, I can feel the engine vibrating oh so slightly, and it feels like a slight miss of some sort. The car does not reverberate or vibrate like it does when in gear.

I have replaced plugs, wires, cap, rotor, O2 sensor, ECT and cleaned the IACV. No CELs. I don't believe that the two symptoms above are related. The car runs excellent other than the irritating idle.

Are there issues within the tranny that could cause this reverberation? It doesn't exactly shift smooth, but I recently did flush and fill with Z1.