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FE Technical Forum / Re: I think I killed my 390 with neglect, advice needed
« on: October 14, 2026, 07:35:23 PM »
My Suggestion Would Be To Drain The Oil, And Replace The Oil And Filter Before You Do ANYTHING Else Involving Turning The Engine Over. You Dont Want The Oil Pump Pumping The Water/Coolant Thats Potentially In The Bottom Of The Pan Through The Engine. If You Have A Bore Scope, Take A Loook Inside The Cylinder That The Coolant Had Hydrolocked. You May Have To Turn It Over A Bit To Get The Debris Out Of It. Spray A Little WD40 In It, And Turn It Over A Few Times. Then Add A Slight Amount Of Oil In The Cylinder, And Spin It Over Again For A Few Times. Then, To Save Un Necessary Tear Down Work, Hook Up A Compression Guage On That Cylinder, And See If It Has Some Compression. You May Also Try Removing The Radiator Cap, And Introducing Compressed Air Into The Cylinder At Bottom Dead Center, (With An Air Adapter Like You Would Use To Hold The Valves Shut While Changing Springs),And See If It Holds Or Whether Air Is Escaping Through The Radiator. Best Case, Its An Intake Gasket That Failed, Worst Case, A Split Cylinder, Failed Head Gasket, Or An Issue With The Cylinder Head Being Cracked Or Rotted Out. A Pressure Test Will Answer A Few Questions, And Give You An Idea Of Where To Start Tearing It Apart. Please Be Sure And Drop That Oil Thats Probably Contaminated With Coolant (Check The Dipstick) Before You Turn It Over Any
More. Hope Its Something Simple To Correct, And Not Much Damage Has Been Done.
More. Hope Its Something Simple To Correct, And Not Much Damage Has Been Done.
