01 4.6 Vibration

[southside2402]

111K. Completely stock. Vibration is consistant before and after tires were balanced. Doesn't really happen at certian RPMS or at a certian speed but it's also not random. My main symptom is that while in park, I can rev the engine and 2K-3K you feel a vibration... Pop the hood and physically feel the motor while it's being revved up and it feels fine. Underneath the car while being revved the exhaust doens't seam to vibrate. Bought the car about a month ago with a salvage title and it's done it ever since. Harmonic balancer doesn't appear to have any nicks or dents in it. I've loosened the serpentine belt and wiggled the hb and it doesn't move at all. My thoughts are it could be a bad hb, maybe a torque converter????, or could it be something with the crankshaft. Keep in mind I've put over 1K miles on it while it's been doing this. Any thoughts, diagnostic ideas, or help at all would be much appreciated. Thanks!

 

[trinity_gt]

I would start with the fact that it's a salvage: What was damaged so badly that it was written off? What work was done to it? Where was it hit?

You're more likely to find a problem creating vibration on the other side of the crank from the harmonic damper (balancer is really a misnomer...): Think flywheel/torque converter.

Does the car have any misfire codes stored at all? A dead or weak cylinder may create a vibration that could be mistaken for other things...

 

[southside2402]

Sorry yeah I should've mentioned that. It was salvaged because previous owner took out a fence and ran the barb wire through the top and the paint of the entire car. Damaged the front bumper and busted the radiator. Doesn't really feel like a miss; a little more consistent than that. Doesn't have any codes coming up whatsoever. I even thought it might have had a blown check engine light, and had it checked anyway but nothing came up.

 

[nyuk98gt]

southside2402,

Look at the motor mounts and transmission mount. Maybe the offroad ride pulled something loose.

Welcome to the forum, too.

HTH,

Chris

 

[southside2402]

Will do... Normally if you rev the motor in park and the motor mount is loose or bad, would you feel it more physically on the motor or in the car itself?

 

[nyuk98gt]

southside2402:

Depends on which mount is bad. If it is on the side that 'lifts' (passenger, IIRC) then you'd see the motor move more and feel it in the car. If it is on the compressed side, you may not see the motor move much more than normal. Of course, it could be the transmission mount, too. Check them all.

Has any work been done to the transmission? As trinity said, it could very well be the flywheel. Sorry for giving you too many things to look at but, you have to start somewhere.

HTH,

Chris

 

[southside2402]

Believe me, any and all thoughts are appreciated. I'll take a look as soon as possible and get back with the findings. Thanks again.