Vibration / Buzz at idle [Archive] - Chevelle Tech

: Vibration / Buzz at idle


mykes68
Oct 7th, 04, 1:19 PM
I have noticed letely that my car has started to vibrate more at idle. It is like a constant BUZZ that comes through the dash. It already vibrated quite a bit due to the loud mufflers but this seems like it is coming from the engine.

The most noticeable thing is when at idle in drive with foot OFF the brake it does it more. But as soon as I put my foot on the brake it quiets down quite a bit.

My first suspect is the Derale 17inch heavy duty flex fan. When I first put it on about 2-3 months ago it was alittle louder than the stock fan.

I thought maybe it was loose or had some play in it. But i checked the bolts and they are tight. If I grab the fan and try to wiggle it I get maybe 1/16 of play.

I also found a post on here that said check the balancer to make sure the outside hasnt seperated from the inside. I checked it out and it seems all in tact.

Any other suggestions. Once I give it some gas it goes away. On the Highway I dont notice anything it drives normal. :confused:

d1_bradley
Oct 7th, 04, 4:36 PM
I'd check for close contact on the driver's side. Header clearance, exhaust, speedo cable, etc. Anything that might be real close, the gap will change when you load the engine.

mykes68
Oct 8th, 04, 4:51 PM
I cant see anything that is touching. The only thing I noticed is that seems like my power steering cap came loose and sprayed all over the side of the fender.

Could it be a possiblity that the belt or pulley got sprayed and now the belt is slipping causing a buzz at idle. Because sometimes it seems as if it is coming up the steering column but then again it seems to buzz the drivers side dash also.

But then again why would it quiet down when I step on the brake but when i let go it gets louder??

d1_bradley
Oct 8th, 04, 6:45 PM
Could be pump. By stepping on the brake, your body is actually attenuating the vibrations coming up the column / firewall. Might also be sure that the booster or master cylinder mounting point is good and tight.

SSWANAB
Nov 6th, 04, 4:47 PM
I have the same problem. One of my headers touches the upper front control arm.

caminokid
Nov 8th, 04, 3:51 AM
I had a very simmaler noise in my 69 el camino that would go away when i stepped on the brake. It turned out to be that the master cylinder was missing 1 of the 4 bolts and was vibrating on the firewall. so I tightend them up and it went away.

Ron_Long
Nov 8th, 04, 5:22 PM
If there is a frame mounted brake line distrabution block. Header could be rubbing it. Happened to me on my 69 Chevelle.