Harley Hank Posted March 8, 2019 Report Posted March 8, 2019 (edited) I have a dodge 230 motor that just started knocking at the bottom. It only knocks at startup & when it's on low idle. Once you rev up the motor a bit the knock goes away.. Any help will be appreciated as this is my first flathead.. Im lost... Edited March 8, 2019 by pinche_vejo More info Quote
Frank Elder Posted March 8, 2019 Report Posted March 8, 2019 Its the same as any other piston driven gasoline engine, pull the motor and inspect the rods are they tight or have bolts moved, rod bearings loose or cracked, crank for fore and aft movement..... burnt or destroyed crank bearings the list goes on. All done easier on an engine stand than on your back under an engine. Sounds like the dreaded rod knock to me, I had a 440 that did the same to me.....turned out the oil pump was weak and not enough oil was getting to the bearings. The higher the rpm the more oil pressure you get, and the knock "went away" when the engine was revved, at start up and idle a weak oil pump will starve the lower end "bearings" of your engine. Don't start it anymore as you may damage the engine further. Good luck. Quote
MBF Posted March 8, 2019 Report Posted March 8, 2019 W/o knowing what your actual oil pressure is showing, you may want to look at the lower half of the engine. If this is in a truck, you should be able to remove the pan from under the vehicle.. Jack the truck by the frame and support it on stands with the front suspension hanging and relaxed. That will give you room to drop the pan and check the bottom end. Quote
Dodgeb4ya Posted March 8, 2019 Report Posted March 8, 2019 Time for a quality rebuild...if you wanna do it right. Quote
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