94 s10 blazer. I think I might have loose flexplate bolts. Mine has the removable inspection cover exposing the converter and flexplate, Anyhow, is it possible to get up in and squeeze with a wrench and tighten the flexpate to crank bolts as is? or do I have to remove the converter bolts and push it back??

 

The flex plate to converte bolts can be tightened in the vehicle. Take the cover off, tighten one, and rotate the engine by hand to the next one. Mark each one with a marker. The flex plate to crank bolts though, you'll need to remove the transmission. Be sure to put some thread locker on EACH bolt. Remove them, put the locker on them and retighten.

 

Lock-tite RED. Make sure the suckers wont be coming back off. Take the inspection plate off at wiggle it. Any movement is bad and it should be obvious. Sadly alot of the ones I see get loose also are ruined by being loose and knocking around.

 

Thanks guys. I had the inspection plate off last weekend, and the 3 converter bolts were tight, no apparent cracks, flexplate super tight, but for some stupid reason I forgot to check the bolts to crank. Such a PIA just getting the cover off. Thinking now thought piston slap, but with the stethoscope sounds like its coming from flexplate

 

what noise is it making?

 

Well when I first start the truck, especially cold, the lifters tick like a sowing machine, but that stops after 30 seconds. The recent separate knock is a quieter rythymic knock sounds like from the bottom end and I "only" hear it at idle. In gear I do not hear it at all or accelerating I do not hear it. But it is present at idle in Park. Pissing me off because I can't isolate it. I changed the oil yesterday, dropped the 5/30 and put in 10w/30 with one quart Lucas. No change. The old oil was dark but no junk in it. I also cut open the oil filter, no apparent bearing material or metal. This is a 94 with 175,000 miles. It seems one by one, part by part, I am having to replace the entire truck!!! The knock sounds VERY much like all the youtube videos of chevy piston slap.

 

if the flexplate was loose you should hear a noise when the starter spins it. It sounds like a knock and is commonly misdiagnosed as a knock.

 

Nah, while starter spinning, quiet. Great oil pressure too.

Took these earlier today

s10 blazer Rod Knock or Piston Slap Cold Start - YouTube

More light knock or piston slap? - YouTube

Warmed up light knock - YouTube

 

Sounds like you have an exhaust leak.