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Strange vibration/pulse. Powertrain or suspension?

KZOO3800

KZOO3800

New member
167k miles.

At 25+ mph there is a vibration that seems only somewhat affected by speed and more by what RPM the engine is at and whether or not I'm coasting. I first suspected the lower left ball joint or the worn out rear right strut , as both have been making noise for about 3000 miles. Either of these seem like a likely cause for the vibration.

I do mostly city driving. In 3rd gear only, if I'm doing about 2500+ RPM and abruptly let off the throttle, there is a moderate jolt as if there is play in the power train. This really freaks me out.

My only guesses are:
-Transmission problem (although recently did a pan drop/filter change 1500 miles ago) The trans fluid level looks great I check it every day.
-Torque converter problem (I hear about these going bad on this car but I'm unsure what exactly might happen to cause a problem).
-Suspension problem: like I said I need possibly the rear right strut replaced and definitely the front left lower ball joint, but suspension can't explain the jolt I get upon de-celeration while in 3rd gear.

Can anyone help me with advice? Especially if you have experienced a transmission problem that started this way. Pleas and thanks in advance.
-Scott
 


could be the motor and trans mounts.

pop the hood and then shift it to reverse and see if the engine moves a lot, try to check it when the engine is cold, in the morning so the idle is higher.
 
I just drove this thing 220 miles round trip (face-palm I know, but I had no choice, we've all been there).

I had to keep it at 55 or 60 on both 110 mile legs of my drive. First I drove at 70-75 because the vibration seemed to disappear completely at higher RPM, until the car got pissed and I could tell that if I pushed it something was going to give. Any bump or disturbance in the road exacerbated the problem.

It got worse whenever I was decelerating, so I used the cruise control and my foot rested against the gas pedal to make sure that even a deceleration of 5mph took about 10 seconds. Acceleration seemed to sometimes minimize the vibration, but it did not eliminate it, so it's definitely worst when I'm letting off the throttle.

When I got off the highway after 220 miles of driving, the engine idled fine, shifted great, and the vibration was about half of what it was on the highway. Even at city speeds the shuddering/vibration is consistent with acceleration/deceleration. When I'm holding steady speed (whether it be 25 or 65 mph) the vibration isn't as bad. I held my ear to all corners of the engine bay and listened to the idle, no noises to be heard.

Any advice? What should I check? If I do replace the mounts is there certain brand or type of mount that is best?
 
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Sounds like you have a wheel out of balance to me. I had the same condition, It started after I rotated my tires, ended up tossing on another wheel and it went away.
 
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