hi all,

i've been trying to diagnose a little nagging problem with my max...that is while at idle in "D" my car vibrates. not violently or anything (tach stays right about 600-650), just an an anoying vibration that makes things rattle in my interior and massages my butt way more than i'd want.

i experience no drivability problems whatsoever right now...just this annoying rumbling vibration thing when i'm waiting for the stoplight to turn green.

so anywho tonight i'm at a stoplight and notice that when i roll down my window, and roll ir back up again...that there is a slight change in the intensity of the dash lights, which gets me thinking.

get home and let the car idle in drive...the vibration gets worse when my headlights are on! turn them off...and it's not quite as bad.

so am i crazy in thinking this may have something to do with the alternator belt? i don't get squealing or anything that you'd normally associate with a loose belt.

come daylight i'll check it out and maybe tighten it up some...but i'm curious as to what thoughts you sharp fellows think.

*jared

 

prolly some trany problem? low fluid? dirty fluid? sorry cant help much

 

It sounds like your charging sysytem is placing the engine under load. Maybe check the connections / battery / alternator cindition.

 

that's normal. the alternator puts more load on the engine at idle, thus the engine drops a little rpm.. so it idles just a tad rougher.

your problem is most likely worn engine mounts. check/replace them as necessary, and I would bet a lot of the vibrations go away

 

i only have a bit of time before work, but the tension on the belt seems to be just as tight as the rest of the accessory belts...

hopefully i can test my batt. tomm.

about the dash lights making that sublte change in intesity after the whindow is rolled up...is that normal or am i just looking too hard at things? =)

*jared

 

i had the same situation and found my alternator bolt broken and the
alternator hanging on for dear life.it made the entire car tremble in drive or reverse not in neutral.hope this helps

 

What rpm does the engine idle at when in park and when in D?

I would reccomend cleaning your throttle body and IACV as well.

 

idle in drive is right about 650
idle in park is more like 800 or so.