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Am I screwed? Loud knocking

Daniel Toro

Active Member
Local time
4:22 PM
Sep 10, 2021
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Ash Vale, Surrey, UK
Loud noise coming from the engine. Though about lifters at first but it's quite loud under the engine also.
Tried a flush and oil change but nothing.
I'm very concerned now.
It's a 440 6 pack.

If driving the noise seems to ease a bit but it the rpm goes up it gets much worse.

I tried to make a video:

Thank you.
Get a length of 5/16 fuel hose, insert a 12 inch length of steel fuel line in one end and put the other end in your ear. Go hunting!!!
My bet is an exhaust flange gasket has blown out. Rev it up when it's dark, and see if you can see a light from the leak.
Mechanical fuel pump? If so, put your ear to that as well. Fuel pump rocker arm broke off mine, it still ran perfectly but mimicked what sounded like exhaust leak or lifters... Very similar to that sound of yours.
If you can't find an exhaust leak or anything else that a homemade stethoscope will tell you, pull the valve covers off and see if everything is normal in there but I'm with the others.....sounds like an exhaust leak.
Harbor Freight has an inexpensive stethoscope. Good to have in the tool box.
Thank you all for the replies, that's much better than having to open the engine. I'll try to pay attention and see if I can spot an exhaust leak somewhere, that option never crossed my mind but it does make sense.
It's easy to over diagnose a problem. With the video you did a fine job of presenting the problem. Please post what you find!
Exhaust leak.. not a knock at all. Run your hand around the back of that manifold while it's running and you will feel the puffs of air.. Don't get too close obviously. :)
Harbor Freight has an inexpensive stethoscope. Good to have in the tool box.
That stethoscope is how I eventually found my issue. Eliminated exhaust leak, lifters, oil pump failure, and eventually found it with the stethoscope... It was my first experience with folks around here. Good times lol

Ticking/knocking after warm up
In the field away from tools, I find. a straight stick, grab it in a fist, stick my thumb out and press it against my ear as though I was trying to plug it. The sound transfers very well.
Great vid of the sound. My pop used a long screw driver to his ear for internal diagnostics. Also, would partially block the exhaust tip with a rag to increase the source of the leak upstream.

If not an exhaust leak check that nothing is hitting your torque converter cover, like a torque converter bolt. But doesn’t sound quite metallic enough for that so exhaust leak is most likely. If you have exhaust manifold gaskets I’ve seen entire pieces of them break loose and get blown out a few times.