98 accord vibration

I'm having issues with my 98 accord and vibrations. I changed the battery about 3 weeks ago since i thought it was about due, appearently i was wrong and my alternator was slowly giving out. Well as i was driving all the electric shut off on me and as i was pulling off the car came to a halt going about 20mph and the wheels locked up. Well i got a jump got it to a parking lot and changed the alternator the next morning. All is good with that, but the issue im having now is that it vibrates really bad in low RPM's, shakes the heck out of the car. When you give it gas from idle it seems to vibrate as well. Once you get it driving everything works the way it used to. The other thing i noticed is that also jerks twice when giving gas reversing. Any ideas what it could be? All mechanics are giving me maybe's right now. I was told it could be as serious as a torque converter or as simple as a motor mount. Any ideas guys?

dave

Well I wish I could give you a definant answer, but I really can't. However as far as motor mounts go, if they were shot, which is common on higher mileage (100k) engines, you would feel vibrations at idle. You would also be able to see a difference. Check out this page:

http://www.3sxperformance.com/engine-mounts.asp

about halfway down tehre is a movie called 'jump around', it shows a mitsu engine with bad mounts on a dyno, notice when he floors it, how violently the engine moves and how far it moves. Engines shouldn't be able to move that far. So put the car in park, let it idle, pop the hood, and have a friend rev up the car, or do it yourself using the throttle cable lever on teh throttle body. If it moves that violently, then it's probably teh mounts.

The fact that it 'jerks' in reverse would lead me to believe it is tranny damage or torque convertor damage, but I don't think that would explain teh vibration. So perhaps and probably, they all took a beating when the wheels locked up...that is alot of force that has to go somewhere, and if your tires didn't start sliding, then the force was dispearsed through the engine and tranny. Sorry.

thanks for the quick reply, yeah i really have no idea what could have happend. You dont think the torque converter could cause all this vibration at a low RPM?

dave

i checked out all the motor mounts and all seem fine. it looks like all the vibrations are inside of the car not in the engine bay. The vibrations are moderate now when the car warms up and seem to vibrate really bad when giving gas, going over that 900rpms then it seems to run just fine, any ideas?

A couple of suggestions, both related to misfires. If it's REALLY bad (as you describe), maybe you're only firing on 3 cyls. Possible cause - bad plug wire. If it's more of a hesitation (and it doesn't sound that way) the EGR valves may need cleaning.

The fact it smoothens out at higher revs fits in with the 3-cyl possibility.

Pull one spark plug wire at a time while it's idling. If any of them makes no difference, then that's the bad one.

i'll check out the spark plugs, my buddy told me to do the same thing after he looked at the car today. He brought it to my attention that it only does at 900RPM, the rough vibrations.

Sounds like the tranny is about to go. I had the same problem on my 99 accord. Vibrating in the front on low RPMs and a few slips here ant there on gears... After 3 months or so.. the tranny blew... I am trying to find out if honda covers the 99 coupe because tranny is a know issue on that model. I heard rumors that they do cover it...