Aluminum Block V8s 4.1, 4.5, 4.6, and 4.9 liter engines.

Northstar knocks when cranking

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Old 12-04-2009, 03:52 PM
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Default Northstar knocks when cranking

Hi, I have a 94 Eldorado, and have been working a few things out, I bought this about a month ago and it wouldn't start, I changed the starter relay, and battery, Now starts but now it has a knocking sound in it as it cranks, and goes away about 99% once it fires. I pulled the belt to eliminate the accesories, still makes noise. Today I pressure washed the engine compartment and blew it dry as much as I could, when I started it to put it back in the garage it didn't make any noise at all, let it run a few minutes to dry out, tried starting it a few more times and it was quiet, I assume once everything dries out it, it will knock again. It doesn't seem internal as I put a load on it, it isn't there. Could this be the harmonic balancer? I was thnking at first maybe a tensioner or timing chain and/or gears, but after it got wet and went away I am a bit stumped. This is a very informative site and am glad I found it with being a GM guy for years, but never owned anything like this. Mostly chevy trucks.

Thanks in advance,
AL
 
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Old 12-04-2009, 08:48 PM
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Originally Posted by Alfonzo
Hi, I have a 94 Eldorado, and have been working a few things out, I bought this about a month ago and it wouldn't start, I changed the starter relay, and battery, Now starts but now it has a knocking sound in it as it cranks, and goes away about 99% once it fires. I pulled the belt to eliminate the accesories, still makes noise. Today I pressure washed the engine compartment and blew it dry as much as I could, when I started it to put it back in the garage it didn't make any noise at all, let it run a few minutes to dry out, tried starting it a few more times and it was quiet, I assume once everything dries out it, it will knock again. It doesn't seem internal as I put a load on it, it isn't there. Could this be the harmonic balancer? I was thnking at first maybe a tensioner or timing chain and/or gears, but after it got wet and went away I am a bit stumped. This is a very informative site and am glad I found it with being a GM guy for years, but never owned anything like this. Mostly chevy trucks.

Thanks in advance,
AL

i would think that unless the harmonic balancer is lose, it would make the same noise, belt or no belt.

it could also be a pulley or any of the accesories.
see what happens when its all dry and you run her again.

the belt is like new, right?



.
 
  #3  
Old 12-05-2009, 09:21 AM
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I ran it without the belt, and still had noise, I put it back on and cleaned engine compartment, and when it was wet it didn't make any noise.
 
  #4  
Old 12-05-2009, 06:25 PM
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If balancer is loose engine will not have oil pressure. Oil pump is drive by "crush" between balancer and machined land on crankshaft. It is possible noise was caused by carbon and it corrected itself.
 
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