I was under my blazer a while back and noticed the ballancer and pully had a slight wobble, so I turned off the engine and checked it out. The rubber was cracked and dry but was not separated and the engine ran smooth. I figured I would replace it anyways. Well today I had it replaced and it still has a slight wobble to it. The engine runs fine and does not vibrate. The wobble is only noticable at idle and I made sure it wasn't just the pully that was moving. Is it normal for the ballancer to move a little?

1999 blazer 2wd

 

Alright, I decided to post a video of the balancer to help explain what I was seeing. When I got home tonight I popped the hood and grabbed my phone. As soon as I looked down, I was stumped. The balancer was now running very smooth with almost no noticeable movement. I'm 100% certain this was not the case earlier today when I picked the truck up. The balancer was moving so much when I checked it a few miles from the shop that... well, I started this thread. I stared at it for almost 10 minutes, let the engine cool down then started it again and checked, smooth. Now I've never actually looked at a balancer minutes after it's has been replaced. Can they move a bit after a fresh install before "running smooth"? Is this still something to be concerned about or should I just keep an eye on it? I took a video anyways. Any input on this would be greatly appreciated.

Thanks,
James

http://youtu.be/9u979fRCsBY

 

if it just has a hair wobble in it then yeah i wouldnt worry about it. i see alot of cars are bent for some reason. ive actually seen those rubber filled ballancers go bad, they make all sorts of banging noises

 

Was just a stock balancer installed or did you have a fluid filled one put on? I have not only seen balancers make noise I have seen them come apart & that makes a nice mess or things when a piece of weighted metal comes flying off at a few thousand RPMs.

 

It was a Dorman balancer, I have put a100 miles on the truck so far and all I can see is a slight wobble (left to right) no belt noise, no engine vibrations.

 

Okay, I'm pretty convinced something is wrong here and I'm going to take it back to the shop Monday. Recap: Thursday afternoon = Wobble, Thursday Night = No Wobble, Friday Evening = No Wobble and I just got home a few minutes ago and the wobble is back. I took a short video on my phone, it moves way more than the video shows (I think my phone's fps are low) but you can tell it's not nice and smooth like the last video.

Blazer 4.3 balancer 2 - YouTube

 

Alright, I made time to stop by my mechanic's shop yesterday. He pointed out that the balancer is fine and it's the pully that has movement. The pully moves left to right like its out of round. He couldnt explain why it was running smooth before but he said it's nothing to worry about??? Is he right? What could cause a crank pully to wobble? I want to take his word for it that there is nothing to worry about, we have been going to him for 15 years without a single issue but the movement at the pully just bothers me...

 

Mine wobbles a tad. May just be the pulley indeed. But like you said it wobbles one day fine the next.....Id make sure the bolts are tight.

 

I would say if for 15 years he has taken good care of you then I would have to say you need to trust his judgement. I think if I went out & really looked mine wouldn't be much different. If it was throwing or chewing up belts or making noises then I would be concerned but I agree from your video, drive it & don't worry about it.

 

I know i'm beating this to death but it just bothers me. Today two Mechanics I work with looked at it and both said it looks like it's either defective or not on right. Now they are diesel mechanics but have some gasoline engine background. I dont want to insult my mechanic by suggesting his advice is inaccurate but I honestly don't feel like this is right. I took one more video. In this one you can see it moving, especially towards the end of the clip. Also you can see the tensioner bouncing. The tensioner is fairly new and barely moved at idle before, now it has a nice steady rhythmic bounce. Trust me the movement is more dramatic with the naked eye, my phone's fps suck and I cant find my camcorder battery.
https://www.youtube.com/watch?v=mrA4...e_gdata_player
https://www.youtube.com/watch?v=Ki-g...e_gdata_player