We try to use the best quality products for your customers, We road tested 28 miles with no problems at that time and did other repairs to truck with no problems. With purchasing rebuilt engines we can't control how re-builders set up clearances and tolerances internally in engines and haven't had any problems like this in over 18 years of using this supplier of engines. Sorry for the inconvenience and we are working on this to get truck back to you so as possible. Thank You