strange knocking?

2016 SUBARU IMPREZA
88,689 MILES • 2.0L • 4 CYL • 4WD • AUTOMATIC
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the car is perfectly kept and serviced with ams oil 10w-30. i am from (Jamaica) the car has a minor exhaust system set up it had received a minor tuning from Elite performance. it runs nice and all however i burst a top hose one night coming in and bought a hose and install top up with coolant i saw 3 small oil spot in my reservoir bottle but none in engine oil(checked dip stick) the radiator cap has a small amount of creamy color. i bought all seals included head gaskets engine oil filter transmission oil etc. when they installed the engine, it idles and cold started normal however when revved at 3,500 RPMs it knocks, the remove and 1 off the four conrod bearing was so slightly dragged i doubted it was even a mark anyways i bought new conrods and piston rings and they re assembled and same noise ..all internal components are fine no shavings no wears nothing at all.. the flex plate checked oil pump checked no signs of oil starvation on the inside .. no one can fine the problem they just say buy new engine.
Aug 21, 2025 at 6:06 PM
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Yep, I have seen a broken/cranked crankshaft which will make this noise. If you remove the crankshaft you should be able to see the crack. Sorry. :/
Aug 22, 2025 at 9:17 AM
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The crankshaft was removed and went to a machine shop and no faults found just a little polish only 1 conrod bearings so so slightly touched it did seem like the prob I bought the set and new rings and still the same sound
Aug 25, 2025 at 6:05 PM
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While the crankshaft was out did you check the wrist pins? Once can be seized in the piston head. If there is just a little stiffness it will cause a knocking noise.
Aug 25, 2025 at 6:07 PM
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I'll have to remove the engine again to fully check I'm giving the car to someone else...u guys need an outlet for repairs and service in Jamaica u would be rich too much crafting from these guys here
Aug 29, 2025 at 6:08 PM
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I am sorry to hear that, I hope everything turns out for you.
Aug 30, 2025 at 9:30 AM