[nibake]

I just got my 2011 Santa Fe back from the dealership.

I have been having a certain clunking/surging that isn't easy to explain. It almost feels like going over the grooves in the road. So much so that one would probably never notice it if you only drove on roads with bumpy grooves. I occasionally feel a bit of jerkiness when slowing nearly to a stop at stop signs and lights. The most obvious thing, though, is the jerkiness I'm feeling on a smooth road when accelerating particularly between 30-40mph. If I accelerate very gradually I don't get it at all.

The way it is so rhythmic makes me think it is a CV joint, but I've never had a CV joint fail so I'm not sure what to relate it to. I have had a smooth-shifting transmission go bad and original I suspected it was a tranny issue but that just doesn't seem to add up as it only happens in a certain speed range with torque and it seems to be completely unrelated to gear or shifting.

Ok, so there was my life story. The mechanic said it was a bad strut. I highly suspect he didn't so much as test drive it. He even said "a bad strut could make the bumps feel worse" :facepalm: Would a bad strut make this happen on brand new, smooth pavement roads? I know it's not related to bumpiness of the road. Is this mechanic blowing smoke?

I'm getting anxious because I have very few miles remaining under warranty and I would sure like to get an accurate diagnostic. Is it bad that I think I'm more likely to get good advice on an internet forum than from a certified mechanic?

 

[Bj Murrey]

sounds like vibration (engine / rotation / moving parts) at a certain speed - start with the basics - not struts lol. Check to make sure your wheels are balanced and wearing evenly. If uneven wear on tires, you likely have a bad control arm bushing / bearing / ball joint / etc. If tires and wheels are fine, move to the motor. Pull off any plastic crap covering the motor, have a friend start it up and slowly rev it up very gradually (like accelerating) through the rpm range to see if you notice any wobbling of pulleys or hear any crazy noises etc.

Sounds like you may have a harmonic balancer / crankshaft pulley that is going out, causing vibration at certain "frequencies" / rpms (hence the name "harmonic" balancer. You can replace it yourself with a couple of tools and some tricks but it's much easier if you have a good impact wrench. Without it you need to keep the engine from spinning backward while removing the bolt, and forward when tightening it back up. I just did mine with no impact wrench so I can walk you through it if you need it. Harmonic balancer is like $40 on amazon or $160 at the parts store locally. I didn't need a puller - I pulled mine off by hand after I got the nut off.