Did you check to make sure you're running on all four? The weird vibration is a lot of the time a symptom of running on only 3. I don't know how engine savvy you are, so I'ma explain this in the most basic terms. 1.Start car 2. pop hood 3. pull each plug wire one at a time 4. listen and feel for any changes in engine operation as you pull the plugs 5. if you pull a plug and nothing happens(ie engine doesn't act any stranger than it already does) you've found the source cylinder of the problem. 6. Turn off car 7. remove the plug from that cylinder 8. check for oil, fouling, etc. 9. replace plug and see if it cured the problem.
If the plug comes out oily, you've most likely got a leaky valve seal(since honda piston rings are pretty resistant to frying). If you're to fix this yourself, it'll only cost ya about $20/valve that you replace, $50 for the headgasket, about 4 hours of your time, and maybe $15 for oil and coolant. If you were to take it to a mechanic, I could easily see this costing $400. I kinda went off on a tangent without knowing more information, but try the plug thing and let us know what you find....We'll be able to help you from there.Good luck
