Terrible thumping noise!!

[V8_power428@hotmail.com]

hey my truck has made a sound like someone hits it with a rubber hammer at random times, the tricky thing is sometimes it keeps going after the truck has been shut off!! I managed to get under the hood one day while it was doing it and one of my heater hoses was pulsing with the Thump! does anyone know what would cause this???

 

[rangerrager]

the only thing i can think of is something with the thermastat.but im not sure
weird

 

[Jorley]

Most likely air trapped in the cooling system. There was another thread on here about the same thing not long ago.
I found it for you. Here's the thread.
http://www.therangerstation.com/forums/showthread.php?t=14552

 

[CraigK]

Possibly steam hammer?
(I've seem this phenomena with a 24" high pressure steam line - scary!)
When pockets of steam created inside your engine block (a very hot spot &/or poor coolant circulation?) condense rapidly. The rapid boiling and condensing might be causing the hammering sound. This would be consistent with the hose pulsing too. What percentage antifreeze are you running?

CraigK