Clankity-Klunk Noise in Oil Pan *RESOLVED*

Williboy

Well-known member
Supporter 2018
Well that's about the best I can describe it except for maybe " a loose socket banging around". Nothing rhythmical, Not a "knock-knock" sound.
Noise comes and goes. Only seems to do it while in idle in Park or Neutral. When in gear it goes away. Higher RPM noise dissipates. . While warming up it's louder, after warm it's less. Pull plugs while running, no difference in noise. Drives great, no loss of power. No flakes on dip stick
Checked with copper tube to ear. Definitely from the oil pan area. Doesn't come from dizzy, fuel pump, alt, water pump, valve cover. Can't hear anything in tranny or torque convert area. Tonight, after about 15 min of testing sound went away.

I pulled all the carpet to replace the floor pans and with all the rust holes I can hear ( and smell and taste) much more so I can't swear it's a new problem. I heard something before but I thought it was a loose air cleaner.

Any ideas??? Bad rod?? Oil pump?? Bad torque convert?? Cracked flex plate??
 
Could be oil pump. From what I've experienced, a rod knock is pretty much always there. You may get lucky and it'll be an easy fix.
 
End play in the crank? I had a junkyard chebby 400 that did that from time to time, I could grab the crank pulley and wiggle the crank in and out 3/16". I dont know what the noise was actually coming from I just knew it was not good so I got another motor and never got around to tearing it down.
 
Hard to say, but it's easy enough to pull the crossbrace and then the oilpan, and then you'd be able to check the oil pump, rods and mains, and maybe even the cam / fuel pump drive.

You might even find a surprise in the oil pan - I found a socket and wrench in one years ago...bonus tools!
 
My engine mech is also saying that a rod knock is fairly consistent, he's also thinking along the lines of cracked flex plate.

Is it possible to unbolt the torque convert from the flex plate and run the motor w/o doing damage???

I'm planning to pull the pan this weekend and take a closer look and I'll check the flex plate so hopefully I'll find more info then, I'm hoping for something easy
 
Williboy":2573c68n said:
My engine mech is also saying that a rod knock is fairly consistent, he's also thinking along the lines of cracked flex plate.

Is it possible to unbolt the torque convert from the flex plate and run the motor w/o doing damage???

I'm planning to pull the pan this weekend and take a closer look and I'll check the flex plate so hopefully I'll find more info then, I'm hoping for something easy

If you have the original fle-plate, then I doubt it. Early flex-plates were just a bent piece of steel that bolted to the torque converter. The ring gear was on the torque converter itself. If yours is set up like that, well then it would be kind of hard to start the engine without a ring gear. And, you can't push the converter back far enough in the bell to clear the studs that hold it onto the flex-plate wthout pulling the tranny, at least not safely...

Do you have a flywheel (with ring gear) or flex plate?

If you're already pulling the tranny to get the torque converter clear, then why not pull the flex-plate while you're there and have a real look?

Mike.
 
Thanks for jogging my memory on the flex plate. The ring gear is on the torque convert. That would sorta make it difficult to start w/o.

I'm going to tear into this weekend and post my (hopefully easy fixed) findings.
 
Well I think I found the culprit of the noise... and luckily it was easy!!!!

The oil pan was just barely touching the belly bar. Both the bar and the pan had a shiny worn spot. And if you think about it, when I would put it gear, it would torque the motor up and away just far enough. I threw a couple washer under the motor mounts to raise the motor and no more noise. (of course one of the mount studs broke so have to get new ones)

I dropped the pan anyways and everything looks great, nothing in the pan and all rods nice, clean and tight, oil pump ok.

Back to the floor pans, interior, disc brakes, steering column, etc, etc....
 
Go ahead and change out both rubber mounts. It is not uncommon for the rubber to separate from the metal mount itself, thus causing the engine to rock back and forth.

Also, stay with a good brand of mounts that are US or Canadian made. There have been several complaints from various member about the rubber separating.
 
Wilhelmus":1e8xpdgy said:
Happened to me three times with the Korean ones. They only send you 2 right mounts, too.

That must be on your Mustang I'm thinking.
You'll be glad to know that on your little 'chero both mounts are the same.

Mike.
 
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