Depends where the knocking is coming from, what sort of knock, how loud it is, what speed and whether it is load and speed dependent.
It is important to have a rough idea of the location or source of the knock in order to decide whether to dismantle or not and if dismantling what to begin checking. Even if you had the patience to make the sound heard with words it would be no substitute for an experienced person hearing it.
Also different people describe noises differently and hear them differently.
Aluminium is a common material used in such engines and it expands about seven times more than steel as it heats up and this is the principle reason why cold engine knocks can fade after warm-up and why some cold engines are silent and are noisier when hot.
Listening through a stethoscope or a large screwdriver is an aid to locating the area of the knock. A load dependent knocking indicates piston or connecting rod problems and if the noise becomes louder and more harsh on load or as the speed increases it signals trouble sooner rather than later
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SOURCE: 1986 FORD 300 SIX CYLINDER ENGINE KNOCKS
Hi Bill 609!
Definitely sound like a rod insert to me. With my practiced ear, I cna tell the difference between a main bearing knock (deeper sound, more of a thudding noise), rod bearing knock (not so deep, gets louder as the engine revs, kind of a rat-tat-tat-tapping noise), and a wrist-pin knock (not quite as loud or deep and gets louder with decelerating RPM).
You can tell which cylinder the knock is on by removing the spark wires to each cylinder one at a time while the engine is still cold enough to knock. (Don't get shocked!)... when you hit the right one, the knock will noticeably quieten or possibly quit altogether!
The 300 Six is a tough old motor and I have seen them survive for years with rod knocks... Just allow the engine ample warm-up time before driving, drive on the conservative side, and keep an eye on oil level and pressure.
An oil and filter change to a higher viscosity oil with a can of STP Oil Treatment (Or something similar) is a good band-aid fix for now, I would recommend Castrol GTX 20/50w... in my opinion, Castrol is the best brand out there, I use it religiously - - - I have a customer with a Chevy Suburban who has followed my advice and adhered to good maintenance discipline that has racked up over 300,000 miles on the original small block and no consumption or engine issues, and is still running strong!
Bill, the temporary fix will work for a while, hopefully a long while --- BUT when it reaches the point that the knock doesn't go away, it is time to park it until the real repair can be done --- otherwise you risk throwing a rod and destroying your engine beyond repair!!!
Please don't hesitate to post a comment or ask if you have further questions. I hope this information answers your question and concerns and wish you well with the Ford. *** And remember to rate my assistance... Your rating is my only compensation for helping you in the free blog!!!***
Thanks!
-WildBill
SOURCE: Car is knocking
Sounds like a bad connecting rod bearing or a carbon knock, de-carbon the engine and retest for noise, if it is still there the engine will need to be torn down the crank refinished and new bearings installed.
SOURCE: Knocking until car warms up
Sounds like a lifter noise. worn lifters can't keep oil in them anymore so over night the oil leaks out. when you start the vehicle, you will hear a ticking noise or knocking noise till the lifters fill with oil again. only remedy is to replace the lifters.
you could try an additive but it's temporary.
SOURCE: motor knocks when first started
It sounds like the lifters are draining down over night. When was the last time you changed the oil? A fresh oil change may do the trick, if not try some hydraulic lifter additive ( you just add to the engine oil)
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