Knocking at front of engine.
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Joined: Jul 2007
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From: Kernersville NC
Knocking at front of engine.
I removed everything, (only block, heads and intake remained) from my engine bay and detailed. I finished re-assembling and started it up. I now have a intermittent knocking at the front of the engine. Knocks several times, then stops for 10 or 15 seconds, then starts again. Nothing looks out of place or skewed in any way. Seems like a pulley maybe. Does the water pump make this kind of noise when going bad? The fan does not have any slop. It is definitely coming from the fan/pulleys/belts area. I know I have some investigating to do, and it could be anything, but does anyone have any ideas?
Thanks
Thanks
Melting Slicks
Joined: May 2003
Posts: 2,387
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From: Meriden CT
Check to see if your harmonic balancer is rubbing. Happened to me before as the balancer was going bad.
I went to a friends shop and borrowed his automotive stethoscope. Pinpointed the noise in two seconds with that bad boy. Try and find one, it is a huge help.
I went to a friends shop and borrowed his automotive stethoscope. Pinpointed the noise in two seconds with that bad boy. Try and find one, it is a huge help.
Melting Slicks
Joined: May 2007
Posts: 3,246
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From: Bay Area CA
pull off your belts one at a time, AC first, run it, then AC and P/S, run it, then AC, P/S and ALT belt, you can run it for a minute or so w/o the Water pump turning, and see if/when it goes away. if it's still there after all the pulls, it may be the timing chain, mine went bad recently, stock plastic cam timing gear, same symptoms as your getting at first.
Melting Slicks
Joined: May 2006
Posts: 2,369
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From: Centerville Louisiana
I removed everything, (only block, heads and intake remained) from my engine bay and detailed. I finished re-assembling and started it up. I now have a intermittent knocking at the front of the engine. Knocks several times, then stops for 10 or 15 seconds, then starts again. Nothing looks out of place or skewed in any way. Seems like a pulley maybe. Does the water pump make this kind of noise when going bad? The fan does not have any slop. It is definitely coming from the fan/pulleys/belts area. I know I have some investigating to do, and it could be anything, but does anyone have any ideas?
Thanks
Thanks
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Joined: Jul 2007
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From: Kernersville NC
Thanks for the great info all!
Red Vette- Shroud is good, and nice looking car!
Joe - The scope thing sounds like the ticket, If taking the belts off doesn't work.
Running man - I'll try the belts first. Hope it is not the timing chain. It does seem to run a little rougher now? Did your's start off missing a little? I was thinking the timing was off since I had the distrubter out? Maybe not!
Croaker - Horsepower display is definatly not my problem (Stock 80 L48). Most likely the problem is the mechanic!
Thanks for your help. I will post when I find the problem.
Red Vette- Shroud is good, and nice looking car!
Joe - The scope thing sounds like the ticket, If taking the belts off doesn't work.
Running man - I'll try the belts first. Hope it is not the timing chain. It does seem to run a little rougher now? Did your's start off missing a little? I was thinking the timing was off since I had the distrubter out? Maybe not!
Croaker - Horsepower display is definatly not my problem (Stock 80 L48). Most likely the problem is the mechanic!
Thanks for your help. I will post when I find the problem.
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From: Kernersville NC
OK. I removed the belts one at a time and lost the knock after I removed the last belt which was the Alt.. The pulley on the alt. seems fine and spins freely by hand as does the fan and water pump. Looks like it must be the crank pulley. What do you think? What can go wrong with this pulley? Of course, I may have put it on wrong if that is possible?
Instructor
Joined: Mar 2007
Posts: 223
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From: Henryville Indiana
I had a similar problem with my 79,Came to find that the alt fan behind the pulley was rubbing the alt bracket when the belt was adjusted.Never saw it until I adjusted my belts one afternoon.
Re-positioned the alt bracket upwards as I was tightening the front bolt and tightened the lower bracket bolt LAST.Haven't had a problem since May!!!!!
Re-positioned the alt bracket upwards as I was tightening the front bolt and tightened the lower bracket bolt LAST.Haven't had a problem since May!!!!!
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Thread Starter
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Joined: Jul 2007
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From: Kernersville NC
I had a similar problem with my 79,Came to find that the alt fan behind the pulley was rubbing the alt bracket when the belt was adjusted.Never saw it until I adjusted my belts one afternoon.
Re-positioned the alt bracket upwards as I was tightening the front bolt and tightened the lower bracket bolt LAST.Haven't had a problem since May!!!!!
Re-positioned the alt bracket upwards as I was tightening the front bolt and tightened the lower bracket bolt LAST.Haven't had a problem since May!!!!!
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Joined: Jul 2007
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From: Kernersville NC
I got it. Well, I know where the noise is comming from anyway. The water pump pulley is making contact with the crank pulley. I think I may have a dent on the edge of the wp pulley. Should they be that close?
Melting Slicks
Joined: May 2006
Posts: 2,369
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From: Centerville Louisiana
You know thats how I found my probem with just the A/C belt it was enough stress to make the noise louder. Mine was cracked around the bolt holes you couldn't see it until I took it off and then if it wasn't for that really light metal dust I could of missed it
Drifting
Joined: Jun 2007
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From: Formerly from the Great White North but now residing in the Desert Southwest NM (The Land of Dis-Enchantment?)
Check your clearance between the harmonic balancer and your waterpump. Some pumps have a boss on the bottom that gets pretty close. It happened to me.
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Melting Slicks
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From: Bay Area CA
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From: Kernersville NC
Thanks
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Joined: Jul 2007
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From: Kernersville NC