Rattle in oil pan below 700rpms

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usar17

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A rattle developed last week while parked with the ac running. Thought it was the compressor at first. Got it home to find the noise coming from inside the pan when at idle. Gonna pull it Monday to poke around. Any spitball ideas awhile at what it might be?

Recent oil change, no more then 10k since GM engine rebuild.

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bucket

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A cracked flexplate or loose convertor bolts can sound like a rattle in the pan too.
 

usar17

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I checked them first

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Honky Kong jr

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A rattle developed last week while parked with the ac running. Thought it was the compressor at first. Got it home to find the noise coming from inside the pan when at idle. Gonna pull it Monday to poke around. Any spitball ideas awhile at what it might be?

Recent oil change, no more then 10k since GM engine rebuild.

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I know GM had a rash of engines missing halfs of the bearings missing.......that was mostly 454s tho if I remember correctly but you would have noticed it before 10k miles tho.
 

Camar068

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not doubting you, but maybe an exhaust heat shield?
 

74 Shortbed

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Does it have stock exhaust system????, heat riser maybe...
 

usar17

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No aftermarket

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HotRodPC

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With aftermarket exhaust, that needs checked well. You'd be surprised at what can ratlle and rattle up against and transfer rattle.


But, bucket suggested cracked flexplate. So how well did you check it? I've seen it several times, where you check the flexplate, and it is in fact the flexplate. As it gets worse, it'll show it's face if that's what it is. 10K on a motor SHOULD NOT have a bearing issue yet, but I've seen guys "rebuild" an engine before, didn't hot tank it, it had metal shavings within the oil gallies from the previous spun bearings. Them new bearings were playing knock knock whose there within 500 miles. He had to pull the engine, hot tanked it, had to polish the crank and luckily it didn't need turned again, and new bearings once again. You know how it is, some people just don't listen and they pay dearly.

Keep a good eye on your oil pressure. Good oil pressure is a good sign it's NOT the bearings or low rpm rod knock.
 

usar17

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Good pressure. I thought it was the flexplate too. Ill pull it and gp over it thoroughly

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84c10Tony

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Friend; "Hey, did you hear me and remember to put that washer on the oil pump bolt?"
Me; "what washer?" "I didn't see a washer" "bolt?" Uhm...
 

usar17

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Haha

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What kind of a noise is it ? A tick, a rattle or a knock ?
 

usar17

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Sounds like a rattle of a loose bolt. Checked all the bolts on the bellhousing and the torque converter. All good. Disconnected the torque converter and pulled it away from the flywheel. Still getting the noise so I know it's engine side. Working on getting the flywheel off now

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usar17

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..... all six flywheel bolts were only hand tight

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bucket

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Well at least it wasn't internal. Did it waller anything out?
 

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