Hey y'all I am not only new to the site but also new to s-series. I have gone to school to be a technician but mainly what they teach you is to rely on technology (i.e. Osilisope, hand held diagnostic computer, the ford computer based program, etc...) like I said I went to school to be a technician not a mechanic which is well and good at a shop with all the right tools but I'm not finished my schooling yet ( waiting for an opening in the coarse I want) and I'm working at home in the driveway. Any way back to the point I have a 1999 Chevy blazer LS 4dr 4x4 4.3 v6 the engine knocks but it's a soft knock almost sounds plastic and it changes inconsistently to the motor like every revolution is different 1 knock them 3 then 1 then nothing then 4 it's nuts .... Leave it to idoll and the noise goes away till a load is applied some times just putting it in drive will do it some times I get down the road a 1/4 mile ... I'm lost some say flywheel is cracked some say torque converter (I don't see how unless it's the bolts) first time I started it when I purchased it the lady's son said it sounded like a rod but when I went to move it it didn't make the noise again till I was 1/4 mile down the road and I had to use 4wd to get out of they're lawn bc it was stuck and it didn't knock at all like I said till I got 1/4 mile down the road ... So like I said I'm a bit lost here so if y'all can help I would greatly appreciate it! I don't own a code reader maybe next check but any other questions mechanics wise I will gladly answer or look into and answer thanks y'all !

 

Ok y'all it's a little unsettling that I got no responses on here but I layed under my blazer with it running and the noise is coming from midway on the engine... Seems to me it's a rod knock after all so I guess it's time for a vortec 5.7 swap and I'll rebuild my 4.3 to put in my eagle give them both a boost in power seeings how I always find myself towing a trailer and want to buy a travel trailer any way any thoughts?