Car shakes going 60mph??

watsup ppl' , i got a 94 grand am gt 3.1 v6 and the car starts to shake at 60mph but only at that speed because if i push the pedal more it will stop and accelerate more or if i deaccelerate. It only happens when i hit 60mph and thats only sometimes it doesnt happen alot can someone please tell me why? I was told it could be the motor mounts? oh and one more thing im sorry for being greedy but its just that i just got the car not too long ago and well i also noticed that inside the coolant resevoir theirs actually rust in and around the walls but a mechanic told me it isnt that serious? so should i get it flushed and risk having it clogged or should i just buy a new radiator? please and thanks for your support

I would say the 60mph shake would be your tires or rims.
And who ever said your motor mounts were causing this, I'd never take it to them to work on :grinno:

It wouldnt hurt to get your cooling system flushed.
Rust occures when not enough coolant was used, like just using striaght rusty tap water.

I use filtered/bottled water in my cooling systems, this keeps iron and other contaminates from poluting the ssytem.

Hope that helps !

Defiantly would say that it is the tires and rims balancing. Should be a pretty cheap fix for ya. I think it cost me 5 bucks a wheel to get balanced. I would also say that you need to get the coolant flushed. The less crap (contaiminents) in there the better.

i agree on the wheel/tire balance also..

mine used to shake really badly in speeds excess of 55mph. Turns out I had one bad tire that had a radial pull (the cords in the tire were not straight) which not only caused the shaking but in order to drive a straight line i had to cock the steering wheel about 10 degrees to the right.