low rpm knocking

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Oct 12, 2004 | 12:54 PM

Nick L.

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low rpm knocking

Hi everybody, My engine is a '75 400 and just recently it started knocking real bad. It almost sounds like something is loose and rattling internally. It is a real loud knock when the truck is idling or at low rpm, but I rev the motor up it goes away until the rpm's drop back down. The engine does have low oil pressure but always did since I put the motor in last year. Otherwise it runs the same as it did before it started knocking. I'm hoping you guys can give me some ideas to look for. Thanks.

Oct 12, 2004 | 08:27 PM

danlee

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From: Delaware

It could be lifters rattling due to lack of oil at low RPM.

Dec 2, 2004 | 06:31 PM

123michigan

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From: newberry mi

ya might wanna try makin sure that your torque converter nuts are tight. i have had a 400 that ratled low rpm like a mother and all that was wrong was loose torque converter nuts

Dec 3, 2004 | 07:28 AM

Nick L.

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Yeah, I tightened them up and after seeing all my main bearings and everything were tight, Im hoping it was just the torque converter nuts that were the problem. I hope to get it started sunday or monday and find out.