Guest crazytrain2 Posted July 5, 2012 Share Posted July 5, 2012 I have a loud knock (similar to rod knocking) which occurs at low RPM and must be from the: water pump belt tensioner pulleypwr steering unitalternatoror A/C unit I know this because it went away completely when I removed the serpentine belt. Sound seems to be originating from water pump but no leaks, pulley isn't wobbly and not squeeling.Would belt tensioner knock if going bad?BTW - belt is brand new. It's to hot for typical trouble check process, so I thought I'd ask for your thoughts first.Thanks,MW Link to comment Share on other sites More sharing options...
DAVES89 Posted July 5, 2012 Share Posted July 5, 2012 Sure it is not your harmonic balancer? Link to comment Share on other sites More sharing options...
Guest Richard D Posted July 6, 2012 Share Posted July 6, 2012 Mechanics stethoscopes are not expensive and really pinpoint sounds. Link to comment Share on other sites More sharing options...
Guest Corvanti Posted July 6, 2012 Share Posted July 6, 2012 (edited) Sure it is not your harmonic balancer?that was one of my 1st problems when i purchased my reatta in march. doesn't take much of the rubber (on the rear - facing engine) to be gone to cause your symptom - and it was tight, not wobbly at all...if that is it, "while you're there", replace the crank sensor!!! Ronnie's site helped me more on those repairs than my service manual. ReattaOwner.com - OfflineEDIT: just noticed Ronnie's site is offline at this time. i'm also ass-u-ming from your signature line that we're not talking about a reatta... same mechanicals? Edited July 6, 2012 by Corvanti (see edit history) Link to comment Share on other sites More sharing options...
Ronnie Posted July 6, 2012 Share Posted July 6, 2012 Buick Reatta Repair Tips and Information - ReattaOwner.com is back online now. Sorry for the inconvenience. Both the harmonic balancer and the Crankshaft Position Sensor are available in The Reatta Store. The bolt that holds the balancer on is hard to remove. Instructions for removal are on my website. Link to comment Share on other sites More sharing options...
Guest crazytrain2 Posted July 6, 2012 Share Posted July 6, 2012 Below is a link to 4 audio recordings I made. Based on comparing it to some YouTube recordings I think you're right about it being the harmonic balancer. If you listenm to them, the one with file name ending in "0013" includes engine start up and shut down. You can really hear the knock at shut down. Please see whether you still think harmonic balancer and not something worse after listening. Thanks much for the help guys.Home - MW Link to comment Share on other sites More sharing options...
Ronnie Posted July 6, 2012 Share Posted July 6, 2012 Remove the belt again. Engine Off! See if you can feel any movement when you try to turn the pulley (outside) part of the balancer back and forth. See if you can feel a clunk. Then take a mirror an look at the balancer from the side where it bolts on. If you see large dry rot cracks where the inside of the balancer is bonded to the drive pulley, or chunks of rubber missing the balance is probably bad.This comes up pretty often. I need to do a tutorial on diagnosing the harmonic balancer when I get some time. Link to comment Share on other sites More sharing options...
Guest Corvanti Posted July 6, 2012 Share Posted July 6, 2012 all i can say with my cheap laptop speakers is that they all sound like mine did before replacing the harmonic balancer and crank sensor.you should be able to see with extra light and/or feel the roughness - missing rubber without removing it.if i was in vegas i'd put a few bucks on that being the problem... Link to comment Share on other sites More sharing options...
NCReatta Posted July 6, 2012 Share Posted July 6, 2012 Without a doubt the Harmonic Balancer. Sounds just like my '89 id when it went bad. Link to comment Share on other sites More sharing options...
Jim Posted July 6, 2012 Share Posted July 6, 2012 Easy to check if it is the harmonic balancer. Take the belt off and start the engine and see if the noise is gone. Link to comment Share on other sites More sharing options...
Guest crazytrain2 Posted July 6, 2012 Share Posted July 6, 2012 (edited) Thanks Corvanti, and yes I went ahead and ordered a new crankshaft sensor as well. You're also correct about the mechanical's being similar, but I try not to abuse making to many requests for help out of respect of the fact it is afterall a Reatta site. And occasionally I like to think I even provide some help (Even a stopped clock is right twice a day )Thanks again for everyone's helpMWJim, just saw your post and yes that was one of the first things I tried and the noise went away. I've never had a H/B go bad before so my first thought was Water Pump, Pwr Str pump, belt tensioner etc. or something of that nature. Now with help it sounds like H/B. thx Edited July 6, 2012 by crazytrain2 (see edit history) Link to comment Share on other sites More sharing options...
Guest Corvanti Posted July 6, 2012 Share Posted July 6, 2012 no, thank you! being a retired/disabled law enforcement officer, you "made my day" in trying to help folks. these "new fangled" electronic/computer cars , have me on a steep learning curve. i would have given up without the help i found here on the forum!!! Link to comment Share on other sites More sharing options...
padgett Posted July 7, 2012 Share Posted July 7, 2012 Have had enough go that a HB is one of the spares I just keep around. Unlike an old Chevvy with a thin ring you hardly notice when bad, there is a lot of rubber in these. At least it is captive. Link to comment Share on other sites More sharing options...
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