Replaced Crankshaft --> Knock from top of Motor Now? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

lanerjo · 02-26-2011, 12:35 AM

OK here's the deal... Stock KA24DE The crankshaft keyway was rounded off and would not hold the woodruff key. Solution replace the crank...

Replaced the crankshaft with a remanufactured crankshaft from autozone with matching bearing set. I double checked the clearances of all the bearings with plastiguage. All were within specs. Every bolt that was taken off of the engine was torqued to FSM spec and then rechecked.

Put the motor back together... Fired it up... Knocking

sounds like it is coming from the top of the engine... The top of the engine was not touched except to reset the timing chain (which the FSM was followed step by step).

nismoman · 02-26-2011, 07:15 AM

might be the chain hitting the guide on top under the valve cover. My sr did this, gave me a heart attack.

lanerjo · 02-26-2011, 10:55 AM

The guides were removed while the engine was apart...

It is my understanding that the KA in not an interference motor. Plus there were no binds, or noises from turning the crank by hand... Still no binds or noises from turning the crank by hand.

The noise sounds like a valve or something though. Which is what is messed up because nothing that was done would have touched a valve.

The only thing I can contemplate being the issue is maybe a piece of the woodruff key or possibly a piece of the oil pump drive (there was a small chunk missing) somehow got up to the top of the engine and is making that noise. There were no unusual marks on the timing chain though, so I see this as unlikely.

:b ash:

nismoman · 02-26-2011, 06:28 PM

The ka absolutely is an interference motor.

lanerjo · 02-26-2011, 07:02 PM

Either way when the engine was going back together there was no binding nor any noises or tough spots when turning by hand.

This is really racking my brain...

Kingtal0n · 02-27-2011, 11:17 AM

i know you dont want to hear this but that is the noise they make when you've got some clearance in the bottom end that should not be there, the diagnosis would be offset usually because it (could) be valvetrain related, of course... but you just changed the crankshaft...

Slammed · 02-28-2011, 10:36 AM

Quote:

Originally Posted by lanerjo

The noise sounds like a valve or something though. Which is what is messed up because nothing that was done would have touched a valve.

:b ash:

Is it a knocking or ticking.. I had a crazy tick noise and i bled the lifters and its really quiet now, need to drive a bit to rid the rest.. Maybe you had your cams/rockers off when you had to redo the timing.. and if you replaced crank engine couldve been upside down? the process takes like 30min- 2hrs

02-26-2011, 12:35 AM	#1
lanerjo Join Date: Jun 2008 Location: Overland Park Age: 42 Posts: 16 Trader Rating: (1) Feedback Score: 1 reviews	Replaced Crankshaft --> Knock from top of Motor Now? OK here's the deal... Stock KA24DE The crankshaft keyway was rounded off and would not hold the woodruff key. Solution replace the crank... Replaced the crankshaft with a remanufactured crankshaft from autozone with matching bearing set. I double checked the clearances of all the bearings with plastiguage. All were within specs. Every bolt that was taken off of the engine was torqued to FSM spec and then rechecked. Put the motor back together... Fired it up... Knocking sounds like it is coming from the top of the engine... The top of the engine was not touched except to reset the timing chain (which the FSM was followed step by step).

02-26-2011, 07:15 AM	#2
nismoman Zilvia Junkie Join Date: Jul 2005 Location: Bowie, MD Posts: 412 Trader Rating: (0) Feedback Score: 0 reviews	might be the chain hitting the guide on top under the valve cover. My sr did this, gave me a heart attack. __________________

02-26-2011, 06:28 PM	#4
nismoman Zilvia Junkie Join Date: Jul 2005 Location: Bowie, MD Posts: 412 Trader Rating: (0) Feedback Score: 0 reviews	The ka absolutely is an interference motor. __________________

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02-26-2011, 10:55 AM	#3
lanerjo Join Date: Jun 2008 Location: Overland Park Age: 42 Posts: 16 Trader Rating: (1) Feedback Score: 1 reviews	The guides were removed while the engine was apart... It is my understanding that the KA in not an interference motor. Plus there were no binds, or noises from turning the crank by hand... Still no binds or noises from turning the crank by hand. The noise sounds like a valve or something though. Which is what is messed up because nothing that was done would have touched a valve. The only thing I can contemplate being the issue is maybe a piece of the woodruff key or possibly a piece of the oil pump drive (there was a small chunk missing) somehow got up to the top of the engine and is making that noise. There were no unusual marks on the timing chain though, so I see this as unlikely. :b ash:

02-26-2011, 07:02 PM	#5
lanerjo Join Date: Jun 2008 Location: Overland Park Age: 42 Posts: 16 Trader Rating: (1) Feedback Score: 1 reviews	Either way when the engine was going back together there was no binding nor any noises or tough spots when turning by hand. This is really racking my brain...

02-27-2011, 11:17 AM	#6
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 38 Posts: 4,649 Trader Rating: (17) Feedback Score: 17 reviews	i know you dont want to hear this but that is the noise they make when you've got some clearance in the bottom end that should not be there, the diagnosis would be offset usually because it (could) be valvetrain related, of course... but you just changed the crankshaft...