Dull knocking

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Oct 15, 2004 | 03:16 PM

blwilli

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Dull knocking

ok, quick question y'all. What would make a dull, solid knocking (like a hammer hitting a steal beam) that is louder at the bottom of an engine?

Oct 17, 2004 | 01:43 AM

hate2loveford

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Assuming that the engine isn't actually thinking of throwing a rod out the side of the block..., check the catalytic converter cover. Mine had a weld or two break and it made a horrible rattling sound at certain RPM ranges until it was rewelded.

Oct 17, 2004 | 09:19 AM

blwilli

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nope, not the cat in this case...its NOTHING like a rattle...nice consistant Knock.

Oct 17, 2004 | 08:48 PM

rusty70f100

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From: Iowa

What engine is it and does it do it all the time? Piston slap sometimes makes a knock.

Does it occur at full engine speed or half engine speed?

Oct 26, 2004 | 08:41 AM

blwilli

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it has the 4.0L (1993 Explorer)...does it ALL the time, worse under load.

Oct 27, 2004 | 10:19 AM

mrshorty

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Worse under load? Is it spark knock (aka ping)? Fairly common to these engines.

Oct 27, 2004 | 11:28 AM

blwilli

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no, it is not a spark knock...no, there are no fault codes, yes, it is worse under load. Not to mention, it is louder at the BOTTOM of the engine, whereas spark knock would be in the heads. No, it is also not a rattling catalytic converter cover (actually, that cover isn't even there anymore).