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Major vibration after rebuild

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Old Oct 22, 2012 | 09:55 PM
  #1  
arad99's Avatar
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From: Weirton WV
Major vibration after rebuild

We finally got the engine back in the 7 and got everything hooked up. The engine fired right up within 5 seconds. We rebuilt it this time because it smoked badly.
The rotors had new bearings pressed in by a local NAPA shop but nothing else was done out of the ordinary. The irons, housings and rotors were re-used from the last rebuild. Nothing was really changed except for the seals and gaskets.
I let it run for a while but it vibrates really bad.
Any ideas?
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Old Oct 22, 2012 | 11:06 PM
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Make sure your plug wires are in the proper locations.

Counterweight installed correctly? Drive-shaft loose?

Golden Marmot?
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Old Oct 23, 2012 | 12:20 AM
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From: Weirton WV
Originally Posted by texFCturboII
Make sure your plug wires are in the proper locations.

Counterweight installed correctly? Drive-shaft loose?

Golden Marmot?

What is a "Golden Marmot"?

Definitely not the drive shaft because the 7 is still on jack stands?

How can the counterweight be installed incorrectly?

I will check the plug wire in the morning.

thanks for the input.
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Old Oct 23, 2012 | 01:11 AM
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From: Weirton WV
Are all S5 counterweights the same? I have an extra one.

Can rotor bearings be pressed in incorrectly?
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Old Oct 23, 2012 | 09:35 AM
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Rotor bearings can be pressed incorrectly but honestly, if they were, you likely wouldn't be able to fit the eccentric shaft through.

Is the engine running correctly, but just vibrating? Sure it's not an accessory with a bad bearing, or a broken clutch fan?

If you didn't swap the counterweight with one from another engine, that's likely not it.

End play alright?
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Old Oct 23, 2012 | 10:16 AM
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start by removing all the accessory belts and running just the engine. if it's still there then determine if it's just a misfiring condition by checking the plugs with a timing light and spraying carb cleaner in the intake while the engine is running.
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Old Oct 23, 2012 | 08:44 PM
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From: Weirton WV
Originally Posted by Aaron Cake

Is the engine running correctly, but just vibrating? Sure it's not an accessory with a bad bearing, or a broken clutch fan?

The engine seems to be running as well as a new rebuild with used housings can. The idle is not even yet but it starts right up. The only accessory on the engine is the alternator and I will take the belt off tomorrow and see if it makes a difference.

If you didn't swap the counterweight with one from another engine, that's likely not it.

I do have parts from the original engine laying around the garage but it was also a S5 T2. I don't think I swapped them though

End play alright?
I ordered a dial indicator and when it comes in I'll recheck the end play.
thanks Aaron
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Old Oct 23, 2012 | 08:48 PM
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From: Weirton WV
Originally Posted by RotaryEvolution
start by removing all the accessory belts and running just the engine. if it's still there then determine if it's just a misfiring condition by checking the plugs with a timing light and spraying carb cleaner in the intake while the engine is running.
OK, thanks Ben. I'll check those tomorrow.
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