Crankwalk or something else?

[Specter]

There is this sound coming, as if something is rubbing against the other, it only comes when the engine decelerates, not at acceleration. There is no sound at idle. The car runs perfectly fine. The Clutch is perfectly fine. The engine is a 2g, it starts so the crank sensor is fine. The rubbing sound only comes at deceleration. And when you crank the engine, there is a hammering noise when the starter cranks the motor. I showed it the 2-3 guys and they are saying that its the flywheel, either that its coming loose, or its having some play. The engine is bone stock and with fairly low miles. What do u guys think?

 

[CSMShaun]

It is certainly possible that it is the flywheel. Do you know what flywheel bolts are in it and what they were torqued to upon assembly?

 

[Specter]

The Bolts are standard and were torqued to factory spec when my last clutch job was done which was like a week ago. The problem was i swapped on to a larger diameter flywheel in order to run a bigger clutch. I was running a very small clutch/flywheel before with a not so strong PP. So the now bigger flywheel had holes which were smaller then the bolt holes on the crank itself. So we drilled the holes bigger. Now what might have happened is that perhaps one of the hole was a little bigger or might be a little out of the line which is causing the flywheel to have some play.
So i just wanted to know how would a crank walk sound like and when does the sound come.

 

[CSMShaun]

Extreme crank walk would sound like rod knock which sounds like a clatter. Where the holes you drilled bigger in diameter than the flywheel bolts? If they are then you could be hearing the flywheel shifting back and forth on the bolts due to the large holes.

 

[Specter]

No the holes are not bigger in diameter then the flywheel bolts, they are of the exact size, the bolts go in the flywheel pretty jammed up, but i think one or more holes is not drilled properly. Just a thought, would excessive play in the flywheel damage the crank? I have not run it above 10mph, and ran only for like 5 miles or so, brought it home, heard the sound couple of times, and shut it down. Should i drain the oil and open up the chamber to see if the crank is fine, also check in the oil any tiny metal pieces? I guess if it is flywheel then there should be marks on the inside of the gearbox.

 

[Specter]

And yes about the sound, checking some videos at you tube of crank walk, the sound is totally different, i see rod knocking sound on idling and at acceleration in a crank walk situation. Where as in my situation i only hear sound when ever the engine decelerates from higher rpm like from 2000rpm down to idle.

 

[CSMShaun]

What clutch did you install in it? Is it sprung or unsprung? What material is it made of? Some clutches are very loud when new. Especially unsprung clutches using ceramic/cintered iron rather than the organic disc.

 

[Specter]

The Clutch is sprung, made of that orgranic material, its totally stock, nothing performance. The noise is very loud and is not clutch related, you could feel the vibration if you put your hand on the head.

 

[CSMShaun]

Unfortunately you are probably going to have to disassemble and inspect to find the cause of your problem. /ubbthreads/images/graemlins/frown.gif

 

[KT]

Title should read "Crankwalk or someone else"

 

[fivestardsm]

[quote name=Specter The problem was i swapped on to a larger diameter flywheel in order to run a bigger clutch. I was running a very small clutch/flywheel before with a not so strong PP. So the now bigger flywheel had holes which were smaller then the bolt holes on the crank itself. So we drilled the holes bigger.



I would say that this is a definet possibility to a problem. As far as I know, You can not run a bigger flywheel without it hitting the case of the bellhousing, and also hitting the output shaft for the transfer case. Are you sure you are actually refering to the flywheel, and not the pressure plate?

What was the setup in question originally designed to fit in?

Any more info would be helpfull, but if you dont have any, then it looks like it is time to take it back apart and inspect it. You deffenetlydont want to destroy the trans because of improper parts.

 

[Specter]

^^ I Swapped the whole gearbox with the bigger diameter flywheel and clutch/PP. My car is fwd by the way. Yeah well i guess i would have to open it all up to check what is the problem, i just hope that the crank is fine.

 

[Specter]

Okay so i have drained the engine oil. I could feel tiny metal pieces in the oil. There are so small that u cannot see them, but you can only feel on your fingers, i do not know the correct word to explain it. I then opened the chamber, the crank seems to be fine, there is no play at all, rotated the crank, seems to be okay. So what should i take from the oil? Will the engine run okay?

 

[Specter]

Would now be opening the gearbox to check the flywheel as it is probably the flywheel causing all the racket.

 

[CSMShaun]

If something in your rotating assembly of the engine has failed you will see the metal in the oil or have large chunks of it in the bottom of your oil pan. Usually an engine that has had failure in the rotating assembly will sieze if you let it run too long due to loss of oil pressure.