Loud engine clacking/tapping noise - Cyl #4
06-08-2010, 12:19 PM
#11
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Originally Posted by Billman250,May 29 2010, 09:20 AM
Scored #4 cylinder.
The high compression in #4 is because of the excess oil getting past the rings, due to the wear.
Seen it before, a few times.
The high compression in #4 is because of the excess oil getting past the rings, due to the wear.
Seen it before, a few times.
09-10-2010, 08:38 AM
#12
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Replaced the retainers/keepers with an AP2 set yesterday, the sound has subsided slightly but it's still there. I'll be taking this to a machinist tomorrow morning, just wanted to see if anyone else has a clue as to what it could be.
09-10-2010, 08:59 AM
#13
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I can almost say for certain you have a scored cylinder. The noise is coming from the piston skirt.
I can say for certain that that noise is not the valvetrain.
I have seen this first hand. the high comp in cylinder 4 guarantees you have scored walls.
Wish i had better news for you. I've dealt with this car for years, and I know all it's noises and issues.
I can say for certain that that noise is not the valvetrain.
I have seen this first hand. the high comp in cylinder 4 guarantees you have scored walls.
Wish i had better news for you. I've dealt with this car for years, and I know all it's noises and issues.
09-10-2010, 09:01 AM
#14
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If you wanna check them, pull the oil pan, and move the #4 piston to the top. If its scored, it will be quite obvious.
Another thing you can do is drain the oil, reach in the pan with a coat hanger, and pull out the FRM flakes.
Another thing you can do is drain the oil, reach in the pan with a coat hanger, and pull out the FRM flakes.
09-10-2010, 11:11 AM
#15
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After I take it in tomorrow I'll pull the pan (again) and thoroughly check #4. I'll snap some pics of it when I get a chance, probably Saturday afternoon/night.
What are FRM flakes? Also, what exactly on the piston skirt would be causing the noise? Not disagreeing with you, just trying to get more details so I know what I'm looking for here.
What are FRM flakes? Also, what exactly on the piston skirt would be causing the noise? Not disagreeing with you, just trying to get more details so I know what I'm looking for here.
09-11-2010, 02:07 PM
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Pulled the pan and baffle plate. Can't really see anything other than the crank/rods and bottom of the pistons... At TDC the rotating assembly blocks the entire view of inside the cylinder. (Pics will be up soon.)
Also I scraped around the oil pan and the drained oil and there are no chunks, flakes, pieces, slivers or shavings of any sort. The oil looks pretty clean.
Will try and snap pics of the walls.
Also I scraped around the oil pan and the drained oil and there are no chunks, flakes, pieces, slivers or shavings of any sort. The oil looks pretty clean.
Will try and snap pics of the walls.
09-11-2010, 02:38 PM
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Status update: I think Bill may be right about that scored wall... 
Can't really get any clear pictures of it, but it looks like there are streaks on both sides of #4 cylinder each about 2" wide.
Still trying to comprehend how that translates into a knocking noise.
Can't really get any clear pictures of it, but it looks like there are streaks on both sides of #4 cylinder each about 2" wide.Still trying to comprehend how that translates into a knocking noise.
09-11-2010, 04:57 PM
#19
Sorry to hear. Billman is the man (no pun intended). His diagnosis are usually correct. With the high compression in cylinder#4, does scoring occur in all cars or under certain conditions?
09-11-2010, 05:13 PM
#20
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Originally Posted by lke2drvgsr,Jun 8 2010, 02:19 PM
I'm still unsure why a scored wall would be making a metal-to-metal sound. It's pretty clear that the sound is coming from the valve train. I'll try taking video of it next using a stethoscope.