slight hollow knocking sound in great detail description

[petter]

i have a 85 2.3 it has a slight hollow knocking sound constantly that fallows the rpms its louder on the bottom and it sounds like its coming from the back drivers side it is louder when its cold but is still noticeable warm and its more noticeable in the cab then outside. the knock is louder at low rpm and gets drowned out a little bit at 3000 but is still slightly there the oil pressure is 60psi cold and 50psi warm after a long highway trip the oil is at 40 my temps never get above 185 with the heater on cold but on warm it drops to 160 any help is appreciated

 

[petter]

when im on the highway oil is at 50 but when i slow down its at 40 but never drops below that

 

[flaminranger]

how many miles? it could just be worn out.
does it do it only when accelerating or also at cruise?

 

[petter]

no clue how many miles it was my uncles before i got it he said he ran the original out of oil and swapped a new from the factory 2.3 mustang non turbo in he drove it for a year or two then parked it it sat for 10 years before i found it fired right up first try i just did minor stuff to it all new seals gaskets including head but its there at cruise and acceleration but its louder during acceleration

 

[petter]

if the engine was worn wouldn't the oil pressure be lower even at its lowest 40 is not bad i dont think

 

[tomw]

A collapsed piston skirt, or one with too much clearance will knock pretty well when cold, and then quiet down some when warmed up. If that is the case, you live with it, or replace the piston, or have it knurled. A rod bearing will knock loudly at idle, but be much less noticeable at higher rpm. Your oil pressure numbers are good, IMO.
Is is a hard sounding rap rap rap or a milder nok nok nok or a low-frequency thud thud thud?
tom

 

[kimcrwbr1]

You can take a long metal rod and use it as a stethescope. just put it on different points on the engine to isolate the closest point. the closer you get the louder the knock, tap, thump. It is kind of fun listening the bearings, lifters, injectors and such. Just be careful of moving parts. any metal rod will work (long screwdriver) just put somthing on the end you can set your ear on.

 

[kimcrwbr1]

if the engine was worn wouldn't the oil pressure be lower even at its lowest 40 is not bad i dont think

The oil pressure is fine did you do a compression test. If the engine has not been run in a long time you need to start it in steps. firt before even starting it you shoud drain a little from the pan and see if there is any water in there or a oil change with filter before you even crank it. Disconnect the plug wires and prime the engine with oil first by cranking on it for a minute or two try and get as much oil as possible to the upper end then start it and let it idle until the oil pressure is all the way up before reving it up. You may have done nothing wrong and need to find the problem and fix it.

 

[pbilt]

i had the head off to change the gasket and while is was in there i cleaned all the carbon out had the head cleaned magged and planed all seals and gaskets where replaced new oil before it was started and radiator flush its not a rap its more of a hollow knock not very noticeable at idle more taking of in the beginning of all gears or during acceloration