So a buddy and i just swapped a newer j35 into my 06 pilot.(trans and chassis have 153k engine has 83k.) and theres a thumping noise that stays steady through entire rpm range, we cant figure it out. My lady completely destroyed the head gasket on the last engine and we poured at least 32oz of coolant out of the mid pipe. It does have a misfire on cylinders 3,5,6 gunna check the coil packs and spark plugs, but need help diagnosing this steady thumping noise.