engine rattle final update
Thread Starter
Drifting
Joined: Nov 2007
Posts: 1,513
Likes: 34
From: columbus ohio
engine rattle final update
a month ago i posted that i heard the engine knock and the oil pressure
was a little lower but not zero. the rattle or knock was a steady sound and does not increase with rpms, which i am use to when thrown bearings go. with the help of frank (midyear) and my friend steve a mechanic it was determined the crank is slightly moving north and south a little. frank does not quite believe that but steve does and when we put
it on the rack and stood in the middle of oil pan you can hear it. steve said i could drive it, but i have learned long ago not to ignore sounds in engines. so steve pulled the 327 out of the 66 and will be bagged. and a zz4 will go in. thanks to everyone jim
was a little lower but not zero. the rattle or knock was a steady sound and does not increase with rpms, which i am use to when thrown bearings go. with the help of frank (midyear) and my friend steve a mechanic it was determined the crank is slightly moving north and south a little. frank does not quite believe that but steve does and when we put
it on the rack and stood in the middle of oil pan you can hear it. steve said i could drive it, but i have learned long ago not to ignore sounds in engines. so steve pulled the 327 out of the 66 and will be bagged. and a zz4 will go in. thanks to everyone jim
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
To stop the crank from going "north and south", all you had to do was shove the clutch pedal in. If you shoved the clutch in and the noise went away, somebody was on the right track.
Intermediate
Joined: Jul 2009
Posts: 49
Likes: 0
From: La Habra Ca
If the crank moves back and forth it should not exceed .006 th.
in most applications. The sound you are hearing seems more like a reciprocating knock. (Excessive clearances/worn bearings etc)
In any event, you could check the crank thrust clear. with a dial indicator mounted on the front or back of the crank...move it back/forth
and see what u get. Also a worn crank thrust will not cause loss of oil press.
in most applications. The sound you are hearing seems more like a reciprocating knock. (Excessive clearances/worn bearings etc)
In any event, you could check the crank thrust clear. with a dial indicator mounted on the front or back of the crank...move it back/forth
and see what u get. Also a worn crank thrust will not cause loss of oil press.
Racer
Joined: Jun 2009
Posts: 333
Likes: 22
From: Chicago Ill.
If you had enough movement with the end play , or thrust of the crank shaft to here a knock , your oil pressure would be way down. If you had carbon on the top of the pistonand it hits the head ,it sounds like a rod knock.
Intermediate
Joined: Jul 2009
Posts: 49
Likes: 0
From: La Habra Ca
In over 30 yrs of building engines I have seen the thrusts literally wiped out on cranks
and never have encountered knocking from it. Loss of o/p yes if its major worn! Just my opinion.
To be safe have your rotating assy inspected
and never have encountered knocking from it. Loss of o/p yes if its major worn! Just my opinion.
To be safe have your rotating assy inspected
Last edited by Engine Doctor; Jul 21, 2009 at 11:07 PM.
Race Director
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From: northern california
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Jim
Last edited by jim lockwood; Jul 22, 2009 at 08:03 AM.
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Thread Starter
Drifting
Joined: Nov 2007
Posts: 1,513
Likes: 34
From: columbus ohio
the car is a 4 speed. and yes the oil pressure went to half of what it was.
steve believed the rear main or thrust bearing is bad (don't quote steve)
i do not know anything about this. anyway the zz4 is in and i am in the process of moving to a condo. move is aug 3 if any of ya want to help. i have own this condo for 4 plus years and let my inlaws live there. they decided to move in with their worthless kids. one month with a son and
another month with their other daughter and pay them 800 a month. those kids will bleed them dry. my wife was the best of their children.
anyway steve and i are going to put it on a engine stand in a week or two
and park it in the condo's garage. when the moving is done i think i will
have frank (midyear) come over and tear the pan off and he can say what the real problem was. jim
thanks for all the info, i am glad i pulled it so i did not completely ruin the block.
steve believed the rear main or thrust bearing is bad (don't quote steve)
i do not know anything about this. anyway the zz4 is in and i am in the process of moving to a condo. move is aug 3 if any of ya want to help. i have own this condo for 4 plus years and let my inlaws live there. they decided to move in with their worthless kids. one month with a son and
another month with their other daughter and pay them 800 a month. those kids will bleed them dry. my wife was the best of their children.
anyway steve and i are going to put it on a engine stand in a week or two
and park it in the condo's garage. when the moving is done i think i will
have frank (midyear) come over and tear the pan off and he can say what the real problem was. jim
thanks for all the info, i am glad i pulled it so i did not completely ruin the block.
Platinum Supporting Dealership
Joined: Aug 2004
Posts: 3,582
Likes: 13
From: St. Marys Ohio
Seems to me I had a crank issue similar to yours years ago in a 65 convertible. Had a pretty good oil leak to go along with it. 
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Tom Hendricks tom@budschevy.com
http://www.facebook.com/pages/Buds-Chevrolet-Buick-Corvette/176730955684255?ref=hl
Corvette Specialist Since 1993
BUDS CHEVROLET
St. Marys, Ohio
800-688-2837
WEBSITE WWW.BUDSCHEVY.COM
HOURS MON-WED 7:00AM - 5:00PM
FFRIDAY AND SATURDAY BY APPT.
OFF THURSDAYS
NCRS # 23758 Miami Valley Chapter ( Ohio )
NCM Founding Member #1143
NADA Classic Car Guide Advisiory Board Member
C5/C6 Registry Corporate Member # 5
My Corvettes. 63, 71, 73, 78.
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Joined: Jan 2002
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If that's the case, a whole bunch of vette owners should hear a whole lot of knocking. I'm not an engine builder, but have built a few and understand many things about the operation of a engine. If your problem is not machanical I would be very surprised. It just hasn't been discovered yet. 
Dennis
Dennis
Le Mans Master
Joined: Jan 2005
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From: Lake Wylie SC
I had a "knocking sound" with a slight loss of oil pressure that turned out to be the warning sounds of a lifter failing. The damage would have been less had I caught it before it failed completely.
Doug
Doug
Last edited by Shurshot; Jul 23, 2009 at 08:26 AM.
