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Knocking then Whistling---Videos up

Ok well I got some numbers on the oil pressure, just throwing out some more possibilities

Cold engine 40 PSI in Park/ 35 in drive

Hot engine 15 PSI in Park/ 10 in drive

its about 27 PSI at 1500 RPMS and about 37 PSI at 2000 RPM's
 
It is really hard to tell by those videos. Can you shoot another except slowly rev the motor so we can hear the knock with RPM variation? Also rev it a little one time so we can see what happens. Do you have any exhaust leaks? If so it will make it really hard to tell which noise is what.

One trick you can use is to take a pieces of an old broom handle and put it up to your ear, put the other end on the oil pan, then the valve cover, etc. and see where the noise is strongest. Works kinda like a stethoscope. Sounds odd but works great.
 
Just another possibility, that sounds a lot like the cracked flexplate that was on my 4.3. The center of the flexplate started cracking, and by the time I got it home it was nearly toast. Took one really good smack with a hammer to knock the center of it out. Thing was that you couldn't see it until you pulled the torque converter back out of the way.

Just pull the bolts out of the torque converter and slide it back towards the tranny. Then look at the center of the flexplate and look for any sign of cracking. Mine wouldn't even hardly flex on the outside because the torque converter would steady it, but the center was toast.
 
New Video

Alright recorded a new video with variations in RPM's in this video you can the slight wobble I mentioned earlier in the thread

http://vids.myspace.com/index.cfm?fuseaction=vids.individual&VideoID=14590492


Also did the stethoscope idea and I get three places that seemed the loudest 1.) The Alternator itself 2.) the front of the left valve cover 3.) the front of the oil pan

I also unbolted the torque converter to check again for cracks, again couldn't find any and when flexing only the outer part flexes, but I'm guessing(don't honestly know) thats normal since its called a flex plate.
Also took some pics of it to see if maybe someone can see something I didn't
Shot with KODAK Z730 ZOOM DIGITAL CAMERA at 2007-07-31
Shot with KODAK Z730 ZOOM DIGITAL CAMERA at 2007-07-31
Shot with KODAK Z730 ZOOM DIGITAL CAMERA at 2007-07-31

Shot with KODAK Z730 ZOOM DIGITAL CAMERA at 2007-07-31

Shot with KODAK Z730 ZOOM DIGITAL CAMERA at 2007-07-31

Shot with KODAK Z730 ZOOM DIGITAL CAMERA at 2007-07-31

Shot with KODAK Z730 ZOOM DIGITAL CAMERA at 2007-07-31

Shot with KODAK Z730 ZOOM DIGITAL CAMERA at 2007-07-31

Also tried prying on both ends of the crankshaft and virtually has no play on the balancer side or the flexplate side unless you really pry on it, you can move it a hair
 
Sounds like a pretty deep knock to me... Most likey not exhaust or valves.

If you notice at idle the flex plate seams to wobble, then as soon as the rpm goes up its as straight as can be.

What is the condition of your oil?
 
Oil is perfect, there is no metal shavings in it and it is nice and clear

Also just did an oil change maybe three weeks ago

Also the motor doesn't burn any oil as far as I can tell, I've never had to add any before an oil change and I check it often, more often here lately
 
Are you running a mech fuel pump?
My vote is fuel pump push rod. It will make a knocking sound that sounds like a rod knock, but goes away with more RPM.
Not sure about the whistling though.
 
I swear I here two different sounds. One sounds like an exhaust leak. Unfortunately the other doesn't sound good at all. That knock is very deep. That's not valve-train or accessory noise. Sounds like bearing noise to me. I would pull the pan down and pull the caps to inspect. Got a feeling you'll find your problem there.
 
Yeah its got a mechanical fuel pump.

I was hoping it wouldn't be bearings but it was pointed out to me if you watch the video closely you can see some walking with the flywheel/flexplate moving forward and backward

Would that mean bearings??? or slight walking normal???
 
mudbog42 said:
Would that mean bearings??? or slight walking normal???
Click to expand...


If you can see it moving, it's too much.

Sounds like a main to me, but it is extremely difficult to tell some times. I would pull the main caps and inspect those bearings first. If all is well, start pulling rod caps and check them.
 
set a budget for a crate 350.. they are pretty cheap about 1300 for a basic..

for all the headache, fuss and tearing down a motor ..get the new motor the way you want it and swap it in..

after all that my "screw it and throw money at the problem" meter is pegged in the just do it section.


hell the piece of mind alone is worth it and people will still pay you decent money for the current motor.
 
This motor was rebuilt not too long ago 350 .030 over,4 bolt main, pop-up high compression pistons ( I think 11:1), Torque Cam, Z28 valve springs, High volume oil pump, Heads have been milled, Factory Corvette intake, 780 cfm carb., 3500 stahl converter. 3 angle valve job. maybe only has about 2-3000 miles on it

I don't want to go from that to a stock motor
 
Holy shiat, why are you running a 3500 stall converter in a 4X4? You try crawling up rocks or a good hill a couple times and you'll be pucking tranny fluid everywhere.
 
What exactly were you doing when this developed? I wonder if that high volume oil pump didn't starve the crank bearings- Keepping the oil in the top of the engine and little in the pan.

I haven't listened to your vid yet (at work) but goin out on a limb here- Take your water pump belt off and fire it up and see if the noise is gone.
 
JEBSR said:
Holy shiat, why are you running a 3500 stall converter in a 4X4? You try crawling up rocks or a good hill a couple times and you'll be pucking tranny fluid everywhere.
Click to expand...


Just to clear the stall converter up, its actually in my 51 Chevy Deluxe:D
 
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