2002 Mitsubishi Lancer, Vibration under moderate to hard acceleration

acceleration
mitsubishi
vibration
lancer

#1

Good afternoon all,

Vehicle is a 2002 Mitsubishi Lancer with 123,000 miles. During moderate to hard acceleration in a straight line, especially in gears 1 to 3, the front of the car vibrates. The harder I accelerate, the worse the vibration gets. Once I get into 4th gear and get up to 40 MPH, I can put the pedal to the floor and while it will do it, it is very slight. Check engine light is off.

Interestingly, on the way to work there is a 25 MPH cloverleaf and coming out of the cloverleaf onto the highway, it did not do it until the wheels were pointed straight ahead.

Deceleration, even when agressively downshifting, is vibration-free.

I do not beleive it is ignition related - the car idles fine, has plenty of power under hard acceleration, and doesn’t do it when going around that cloverleaf. (As a side note, about a year ago a plug wire went bad, leaving one cylinder with no spark. In this case the engine vibrated violently, but was obviously down on power.)

There are no strange noises in the front end. No clicking around corners typical with a failing constant velocity joint, and no mechanical thuds or sqweaks over bumps I’d expect from a failing ball joint or bushing.

I am having some unusual tire wear on the outside edges of the tires, like you would see with under-inflation, but tire pressure is fine. In my mind, this points to bad ball joints.

It still has the original constant velocity joints and axles as well as the original ball joints. The one motor mount I can see looks okay. I’m thinking in order of liklihood (most likely to least likely):

  1. bad axle
  2. bad ball joints
  3. bad motor mount

Anything else I need to check? Wheel bearings? If I do replace the axles, I will replace the front wheel bearings while I’m in there.

thanks much,
ben


#2

Is this a manual car? I was wondering if your clutch could be slipping.


#3

If I was a betting man, my bet would be on bad inner CV joints.
It is entirely possible that ball joints are also worn out. but I believe that the vibration on acceleration is from worn-out inner CV joints.


#4

Good evening all,

Thanks much for the replies.

Yes, it’s a stick shift. The clutch seems to be okay - no signs of slipping other than the vibration. The last time I had a clutch start to slip (on a 1982 Pontiac J2000!) it was pretty apparent - revs would increase with no speed increase, especially in 3rd gear going up hill.

I will try the Click and Clack patented clutch test if I get a chance this weekend. Although I probably won’t use a tree, though. With the front end of the Lancer being mostly plastic, if the clutch doesn’t slip, I’ll probably mess up the entire front of the car! I’ll probably just try to start the car in third, giving it all the gas I dare. :slight_smile:

I’ve got the change the oil in it soon, so I’ll take a look at the axles.

thanks,
ben


#5

Sounds like it would be a good idea to ask your shop to put it on a lift, do an inspection of the driveline for play, and play in the suspension system components. If that is all ok, maybe all you need is an alignment. Has anyone hit a curb by accident just before you started to notice this?