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knocking sound on fresh rebuild

Started by AFrechette, July 11, 2019, 12:46:38 PM

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AFrechette

Hi Folks,

Here's a terrible sound on a freshly rebuilt 1960 390.   The tone sounds higher than a rod knock, but any suggestions are welcome. It was rebuilt by a reputable shop here in Portland OR. 

Here's a link to the video.

https://youtu.be/OekGHGabNAw


Ideas?

Thanks,

Allen

TJ Hopland

Video says its unavailable.   

Have you talked to the shop?    Did they have the whole car?  Or just the engine?  And if it was just the engine did they do a run/break in on it?
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Eric DeVirgilis CLC# 8621

Need to go back to the shop - pronto.
A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute

chrisntam

1970 Deville Convertible 
Dallas, Texas

AFrechette

I did the break in on it, and followed the normal fast run to break in the cam/lifters.   My guess is it's a rod knock but it sounds a lot higher tone.

We have nicknamed this car Christine...




goob

Was the noise evident upon initial start up or did it appear after the break in process? it would be a great help to get the video working, you'll get several more opinions...but I would suggest you contact the rebuilder for his opinion.

AFrechette

It took YouTube a few minutes for the video to go live...should work now.

This noise developed after a few hours of running.   Hell of a racket.

Thanks!

hornetball

Video doesn't work.  Is it marked "Private"?

AFrechette


Odd.  I reposted it so this is the new link.   It shouldn't be private?

Thanks!

https://www.youtube.com/watch?v=8l-iojqbIy4&feature=youtu.be


INTMD8

Strange. Doesn't sound like bottom end as it's irregular and not rhythmic/consistent.

(still possible I suppose if it's spinning a bearing).

Have you tried stethoscope or even a screwdriver listening around to pinpoint the area of the noise?

Try running it with no belts?

AFrechette

Not yet.  Sure sounds like it's coming from beneath the intake.   I am going to validate oil pressure before I run it anymore.   The dummy light goes out immediately, but the gauge I added shows 20lbs.  That's got me scared. 


DeVille68

Just a guess: one of the timing chain gear bolts that attach to the camshaft could be too long and hitting the block behind it?

I just rebuild my my 472 and had a problem while break-in the cam, wiped out a lobe. Sounds a lot different. A rod bearing that had turned caused the rebuild - also sounds a lot different.

Your video sounds like something that is hitting something every revolution. Watching the video a few times it seems to me that the knocking sound comes from the outside of the engine? Check the fan and every piece on the front of the engine.

Best regards,
Nicolas
1968 Cadillac DeVille Convertible (silver pine green)

AFrechette

Will do.  The sound is changing and getting worse.  Crazy racket.  Never heard anything like this.  I have been restoring cars since 1976.   

AFrechette

Mystery Solved...

Collapsed lifter...push rod was rapping on the valve cover...that's a new one for me!


The Tassie Devil(le)

Definitely an odd sound, but glad to see that it was not a major problem.

BUT, having said that, hopefully it will just mean an intake manifold and valley cover removal, and a simple lifter extraction.

Bruce. >:D

PS.   Could they have been Chinese Lifters?
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

AFrechette

I was able to pull it out the top with a set of long hemostats.   BTW, would the rocker shafts normally get cleaned in an engine rebuild?  This one is full of crap!   Not sure if these can be disassembled...??

Allen 


INTMD8

During a rebuild rocker shafts should be completely disassembled/cleaned/inspected/re-assembled (if no wear issues).

Make sure the shafts are oriented correctly or the rockers won't get oil.

Jeff Rosansky CLC #28373

+1 on the crappy rebuild. That really sucks.
I am going to suggest you do an oil change and cut open the filter. If the rockers are full of crap there's no telling what else is in there. Then put in fresh break in oil.
Jeff
Jeff Rosansky
CLC #28373
1970 Coupe DeVille (Big Red)
1955 Series 62 (Baby Blue)
Dad's new 1979 Coupe DeVille

Jay Friedman

Quote from: INTMD8 on July 11, 2019, 07:49:37 PMDuring a rebuild rocker shafts should be completely disassembled/cleaned/inspected/re-assembled (if no wear issues).   Make sure the shafts are oriented correctly or the rockers won't get oil.

I totally agree, though I'm not familiar with 1960 motors.  My experience with my '49's 331 motor is that it's not easy to clean out the interior of the rocker shafts without removing the swedged (is that the right word?) in plugs at either end.  You would have to poke into the various holes with brushes and/or dip the shaft in a powerful solvent.  I've once even put a small chain through 2 holes in the shaft and then shook it around with mixed results.  If you remove the end plugs it's much easier, but then you would have to "re-swedge" in the plugs, which if not well done can pop back out, causing a major loss of oil pressure.  An alternative solution is to buy brand new rocker shafts from Terrill Machine, DeLeon, Texas for $38 each. 

Other points that need cleaning are the tiny holes in each rocker arm through which oil is distributed to the surface on which each rocker arm rotates, as well as the pivot point between the rocker arms and the tips of the push rods.

On a '49 (is a '60 the same?) there are notches cut into both ends of the shafts which when installed must point toward the center of the motor.  As  INTMD8 wrote, this orients the many holes in the shaft correctly in relation to the rocker shaft brackets (which hold up the shaft), through which oil is distributed to the interior of the shaft, then the rocker arms and the push rod pivot points. 
1949 Cadillac 6107 Club Coupe
1932 Ford V8 Phaeton (restored, not a rod).  Sold
Decatur, Georgia
CLC # 3210, since 1984
"If it won't work, get a bigger hammer."