Symptoms of bad Motor Mounts...???

[DigDeez]

My car has been feeling very rough at speed pass 55mph. Not all the time, but the car feels and sounds very rough and runs rougher and louder. The car feels like a car where the mufflers are purely shot along with holes in the exhaust pipe. I've just had a new flex pipe and two new Summit Turbo's installed with Ravin tuner series dual exhaust tips.

It must be said that I can't recall the car feeling this way before the exhaust work, but I don't believe it is the cause, but maybe it is. However, the car feels very scary during this rough running and causes me to slow down.

I did slide into a curve banging the front/right wheel into it. Would a bent rim cause this rough running?

I will first have the suspension components hand checked. I don't think its the rotors, or balancing........the car doesn't vibrate on braking! Just had the wheels balanced about two months ago.

**Also, would bad Motor Mounts cause this? How many mounts are there, including the tranny mount?**

Any thoughts!!!!!!!!!!!!!!!!

DigDeez

 

[shobikes]

I would first definitely check for a bent rim/blistered tire/broken radial belt, especially since the symptom is speed-sensitive rather than RPM-sensitive. It seems if it were exhaust related you'd get this vibration every time you got above 2200 RPM (assuming 55 in top gear).

I would also make sure your new flexpipe isn't contacting the underside of the body anywhere, transmitting vibration. The exhaust should be isolated from the car by rubber mounts.

One good sign of bad engine mounts is a shiny spot rubbed on the top front intake plenum, as the engine will tend to rock backwards as motor mounts go south. There are three - front, rear, and transaxle.

Sounds to me like a (BAD) balance problem.

 

[Jason Bowles]

First off a bent wheel wont make the car run bad. It will just cause a vibration at and above 55-60. Motor mounts, well I had to replace a motor mount in my 1993 and did not even know that the mount had been busted until I took it in, there was no vibration (but that does not mean a different motor mount wouldn't cause this problem.

Here's a question: How old are the tires? And if they're significantly worn check each tire thoroughly and see if there is a small bulge (a tire split) in the tread. If so there is your problem. If that's not the problem and the vibration is in your steering at 55mph your front rotors are bad, if it's not in the steering your back rotors are bad. Don't trust your eye, take them in and have them check or even turned it costs around $20.00 a pair.

That's the best advice I can give you.

Jason Bowles