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-   -   Clunking sound when turning motor by hand, is this normal? (http://forums.pelicanparts.com/porsche-911-technical-forum/739584-clunking-sound-when-turning-motor-hand-normal.html)

Norm Faustino 03-17-2013 06:04 PM

Clunking sound when turning motor by hand, is this normal?
 
So I rebuilt my motor 6 years ago and the car has not run since, never was. Now I know there are all kind of questions as to why but it's a long storyto do with health and job issues. So, I am finally getting ready to finish up and install the motor and trans but I went to turn the motor with a wrench on the crank bolt to make sure it's not bound up and I discovered a slight gadoonk-gadoonk clunking sound coming from the flywheel end of the motor feels kind of like a dull metallic sound like a rod knock. I am totally puzzled because it had no such noise before when I put the cases together and timed it etc. Now I wonder what it could be. Does anyone have their motor on a stand that could tell me if this something to be concerned with? I need to know if i am in for another total rebuild of a rebuilt motor. LOL! :D

Norm Faustino 03-17-2013 06:54 PM

technical bump. Seriously, No one has an idea?

Plays with cars 03-17-2013 07:28 PM

Scratching my head as to what it could be. But it is a safe statement to say "no" this is not a normal noise.

Always in the same spot in the crank rotation? Constant rotation or rocking crank back and forth? Every revolution, or every other?

Tippy 03-17-2013 07:31 PM

Dumb question, but are you turning the engine in the right direction?

Norm Faustino 03-17-2013 08:10 PM

Well yes, but it does it in both directions which is why I am worried about it. because it will be there while accelerating and downshifting or lifting off the gas so I really am going to have to address this. I always regretted not installind JE Pistons for the rebuild so maybe I will hurt the credit cards a bit.:D

Reiver 03-17-2013 08:13 PM

You should not turn the engine over the wrong direction...it is just not designed to do that.

Porboynz 03-17-2013 08:54 PM

Clutch and pressure plate fitted but still seperate from the gearbox? Could be the clutch release bearing flopping around.

Norm Faustino 03-17-2013 09:01 PM

Quote:

Originally Posted by Reiver (Post 7335234)
You should not turn the engine over the wrong direction...it is just not designed to do that.

Yes that's true but we're talking about just rocking it back and forth. How else would you troubleshoot a knock like that?

Norm Faustino 03-17-2013 09:15 PM

Quote:

Originally Posted by Porboynz (Post 7335274)
Clutch and pressure plate fitted but still seperate from the gearbox? Could be the clutch release bearing flopping around.

Actually, it is still seperate.

James Brown 03-18-2013 01:55 AM

you should just hear the piston rings slicing in the cylinders, a gadoonk sound might be something hitting on the flywheel? check that area close for anything that might hit the case as it rotates. That's all i got.

T77911S 03-18-2013 04:04 AM

does it happen at the same point/angle of rotation every time?

does it happen each 360 degrees or every other rotation?

are the plugs in or out? if out, any resistance? all pistons moving up and down?

sounds crazy, but turn the motor upside down on the stand. any noises. turn the crank over again?

put a screw driver to your ear and have somone else turn it over and try to narrow it down

Norm Faustino 03-18-2013 04:52 AM

Happens at all positions of the rotational plane, even upside down and I 've been able to isolate it to the flywheel end of the engine. It seems to me like play in a wrist pin or a rod end. Thanks for the input guys but I am too much of a worry wart to notgo back in and find out what's up. keep em coming and I will keep you posted on the findings.

T77911S 03-18-2013 06:35 AM

nothing consistant? like every 90 degrees? it happens more than one time per rev?
you know, i want to say i have heard the same thing on a motor but i think it was on a engine in a car. no odd sounds when running and no other problems. i will have to let it simmer for a while see if i can remember

Norm Faustino 03-18-2013 07:25 AM

No constant pattern at all, it only happens when I back and forth the crank like you would if you're trying to detect radial play. If I continue spinning in one diection I dont hear anything. Mybe I shouldn't worry since the motor only goes in one direction huh?

aj88cab 03-18-2013 07:42 AM

Take your chain covers and valve covers off and see if you can localize the noise before you go "all-in".

techman1 03-18-2013 07:43 AM

Valve covers off? Able to see the rockers? Any jump in time with the clunk? Wondering if one of the valves could be sticking open.

pdtweeks 03-18-2013 08:33 AM

sounds like crankshaft end-play to me, if you're just pushing the wrench one direction, then the other....depending on how much play there is, it could be "normal" ?

Norm Faustino 03-18-2013 10:38 AM

I would love it if John Walker's workshop could chime in on this.

James Brown 03-18-2013 10:57 AM

i vote on starting that sucker up, it will all seat in

T77911S 03-18-2013 11:12 AM

i thought it was a consistantly happening noise buy turning continuously in one direction.

at this point i think i would put it in. pull the plugs, turn it over to build OP then fire it up.

i still think i have seen this before, just cant remember. it might have even been on my 2.7


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