Kurt Wallis
Newbie
I recently purchased a K3500 dually 454ci. The engine was recently rebuilt or they said. It does have all new gaskets and is very clean. After I got it home I did a compression test all cylinders were at 155psi. After driving it around town I noticed that When it's cold it doesn't smoke but When you start it up after you have driven it it puts out a small cloud of blue smoke. I figured the bottom end was rebuilt but he just put the old heads on with out going through them. Then I went on a trip 640mil to hall some furniture. Going there I was empty so it was easy going. All went well till the last gas stop on pulling out as I accelerated at 2000rpm I got a lifter tapping if I left off the gas back down to 2000 it would go away. I could go 75prh at 2600rpm with no noise as long as there was no load on the engine. I pulled the valve covers off all was tight so I came home empty. The hole trip home was the same no load on the engine no noise or below 2000rpm. I thought it might a lifter and cam eating each other as they may not have been matched up When it was put back together. Some have said weak valve spring. My experience with small block engines is broken springs but you have a dead cylinder. This thing ideals fine and runs smooth until you get into it. I am out of ideas