2002 2.4L engine vibration problems

After a snapped mount and now a cracked manifold, I have come back to this forum for help. Now, I was raised on Dodge V8's, so excuse me if I don't really know much about front-wheel-drive and smaller engine setups. During the past few thousand miles, my engine seems to vibrate more than I can ever remember. Around 2500-3000 RPM, it does it the most, making everything in the car vibrate, to the point where I can tune the sound according to the RPM's. I don't want to replace this manifold until I get the problem fixed, because I know that with my luck I'll break the new one within a week. What can be making my engine vibrate so dang badly? At roughly 59800 miles, I had the timing and "balance" belts replaced and the engine serviced (FYI I just rolled over 65555 miles). I have no idea what the balance belt is, only that it is supposed to be changed near or at the same time as the timing belt, so I had that done. Could this belt be the problem, is there some calibration that could have been done wrong when replacing it? Please help me ASAP, I'm sick of my car rolling to the sound of a buzzing engine. :banghead: :banghead: :banghead:

Well, here we go. HEADS-UP FOR ANYONE GOING THROUGH THE 60,000 MILE SERVICE: Make sure that ALL tensioners on the timing belt are serviced/replaced. The culprit in this particulr problem on my car was the hydraulic tensioner on the timing belt. According to Hyundai there are actually 4 tensioners, with the hydraulic tensioner providing the brunt of the actual force. But as my mechanic explained to me, according to Hyundai, this tensioner does not need to be replaced during the 60k service or at time of belt replacement. Have it done anyways! The fact that this tensioner failed has already cost me over $200 in exhaust work, not including my current mechanic's bill that I will get tomorrow when I pick the car up. Plus, had this not been caught, had the belt actually stretched a bit more, and jumped or lost a tooth.. yea, not good.

Also look at the motor mounts.
My 99 vibrated quite a bit before I changed the passenger mount, made all the differnece in the world.
I hope your car last's a while.
Mud

The hydraulic tensioner definately needs to be replaced. We replace it whenever we do a timing belt here in the shop, along with the balance shaft belt on the 2.4L.

Yea, I got the balance shaft belt replaced. The thing that got me is that the balance shaft belt was recommended-replacement at time of replacement of timing belt/60000mi service. But this tensioner, an integral peice of the timing system, is mentioned nowhere in the 60000mi service description or in the details/instructions given to outside shops by Hyundai. Even when I called the Montgomery Capital Hyundai shop, they told me straight up that they only visually check it themselves when they do this service.