Infoneeded: Starting car, makes a wierd sound(knocking): please help

[OrangeMustangGt]

my car has been sitting for around a day, and when i went to start it up, for the first second it made a knocking sound that imediatly went away. What could this be? My only clue is, my old f150 with 200,000 miles make sorta the same sound for like 8 secs when it first starts up, untill it gets oil pressure. COuld there be something failing with my oil pump, or what can i do about this, would anyone know where the sound could be coming from? it only does this when its been sitting for a while, same as my pickup. Thanks

 

[StangJonGT]

Could be some piston slap, but it is likely valvetrain noise. Change your oil to a good synthetic and monitor the level daily.


Jon

 

[Afastgts95]

Are you a quart low on oil?

 

[OrangeMustangGt]

hmm, i will go and change to synthetic oil, i may be low also, damn rear main seal, thanks guys

 

[KingDiamond]

Check your harmonic balancer too.

 

[fearless302]

mine does the same thing.......maybe someone will shed some light on this topic...

 

[StangJonGT]

Check your harmonic balancer too.

Usually that will affect vibration and idle, not emit a sound. This sounds very much like an oil starvation problem.



Jon

 

[The Hitman]

Change the oil and filter and monitor the level. What kind of Oil Filter are you using? Most of them have a valve that prevents ALL the oil from draining back into the pan and leaves some in the filter so that a "dry start" does not occur. These valves can go bad leading to a dry start every time you start the car. Change the filter and monitor.
It's very unlikely that it's the pump. Not that they don't go bad.. But RARELY.
Start small and work your way up.