I'm pulling out what little hair I have left with this one.
My 351CJ makes a whistlen sound at the front of the head behind the power steering pump bracket.
The noise will appear only after it has warmed up not when it's cold.
I have checked for any vacume leak or crankcase leak by isolating the pvc valve, carb spray over all intake areas and even checked for header gasket leaks and its none of the above.
By using a peice of tubing and tracing the sound, it is right behind the pump bracket at the head near the block and the gasket.
there is no coolant loss or temp changes from running at idle to freeway speeds.
The sound does not change in eather pitch or volume with engine speed changes, it is most noticable at idle and is still there with a rise in rpm but gets drowned out by the noise from the fan.
The only thing that is differant from before is the addition of an alum highflow water pump from stock cast pump.
Now I made sure the head gaskets were on correctly (has tab showing) when i rebuilt it and it runs great.
But I do remember that the coolant passage area of the gasket had small amount of metal showing in the inside where coolant passes.
Could the flowing coolant over this cause the noise like a tuning fork?
As it only appears when it stars reaching operating temp and after the thermostat opens.
Any Ideas DH?
PB
My 351CJ makes a whistlen sound at the front of the head behind the power steering pump bracket.
The noise will appear only after it has warmed up not when it's cold.
I have checked for any vacume leak or crankcase leak by isolating the pvc valve, carb spray over all intake areas and even checked for header gasket leaks and its none of the above.
By using a peice of tubing and tracing the sound, it is right behind the pump bracket at the head near the block and the gasket.
there is no coolant loss or temp changes from running at idle to freeway speeds.
The sound does not change in eather pitch or volume with engine speed changes, it is most noticable at idle and is still there with a rise in rpm but gets drowned out by the noise from the fan.
The only thing that is differant from before is the addition of an alum highflow water pump from stock cast pump.
Now I made sure the head gaskets were on correctly (has tab showing) when i rebuilt it and it runs great.
But I do remember that the coolant passage area of the gasket had small amount of metal showing in the inside where coolant passes.
Could the flowing coolant over this cause the noise like a tuning fork?
As it only appears when it stars reaching operating temp and after the thermostat opens.
Any Ideas DH?
PB