ok so yesterday i was coming to a stop and making a right hand turn. everything was normal. i proceeded to accelerate out of the light and the car started to vibrate horribly. the engine doesnt run any different and holds idle really well but it vibrates really really bad. does this sound like a broken mount blown engine what??? car has 180k miles on it

 

If the engine runs fine and idles solid, chances are you didn't blow your motor (whew).

Why it's vibrating? I have no idea. Are there any specific noises associated with the vibrating? Perhaps the fan-shroud is hitting the fan?

If you're worried, a compression test takes about 5 minutes.

But yeah, could be a motor-mount I suppose.

Does it vibrate when you're 'free-revving' or only under load? (or both?)

You should pop the hood and manually play with the throttle to see if the motor's actually jumping around, or if it's just the fan hitting the shroud.

Also, if the car's turbo, it could be your turbo to exhaust mani. bolts coming loose. They have a tendency to come loose causing a CRAZY vibration/noise under boost.

 

could be a busted mount, if you had a blown engine you would notice a big loss in power

 

no loss in power it actually runs great. its weird. just in neutral free reving it really vibrates. up until about 20 mph it really shakes the whole car. then at about 30 it doesnt shake or vibrate anymore. it sounds like a heli chopter though when it starts it vibrate.
a buddy suggested that the crankshaft went out on it. he said they are common but i would think if it idles fine and hasnt lost any power that it wouldnt be the case.

oh yeah no fans shroud and when i opened the engine lid and watch i didnt see anything shaking or anything hitting anything. the motor wasnt bouncing around. to me it sounds like the drivetrain. maybe drive shaft something with the tranny of flywheel. idk though

 

Well that's weird about it just 'coming out of nowhere'. Maybe it's a busted tranny mount or something? Where does the vibration "feel" like it's coming from?

So it's speed related and not RPM related?

There is no crankshaft in/on a rotary, so your buddy doesn't know what he's talking about, lol.

 

i know there is no crankshaft in a rx7. i think he used the term for me to understand the motor although i think he thinks i'm a idiot which i'm not.(ok extremely long run on sentance lol)
its def rpm and speed related. the more the rpm the more the vibration. but the higher the speed the more it goes away if that makes sense. i guess i just need to get under the car and check it out tomorrow.
oh yeah it feels like it is coming from the tranny area and the driveshaft tunnel in the area.

 

180k miles? You have problems with your drivetrain it seems. You would NOTICE a blown engine. Check trans, driveshaft, and rear end.

 

either worn out motor mount or trans. mount

 

You mentioned it happenned in nuetral though when free revving, so how is that drive train related and what the hell is a heli chopter and engine lid?

 

sorry bout the terms. i come from a mr2 background and we call the piece that covers the engine the engine lid i should have said front hood. so sorry. and i meant the car sounds like a helicopter(sp) while reving it.
also it didnt have in neutral it happen as i pulled away from a light.

 

yes he mentioned it occurs when free revving, what little torque our stock motors put out is enough to get the motor bouncing and twisting around, especially with a worn out motor mount or even worn trany mount therefore it can be considered drivetrain related.