Quote:
Originally Posted by tiso_us
Good read!!...Thanks, I had no Idea these cars had this kind of problem with them. Here is what i did next.....after replacing the oversized bearing, i put the engine back together, but before i do that i want to make this note about the bearings first, the bearings had alot of play from side to side, something like the width of a dime on both sides.
With that said i'll continue.....after putting the vehicle back together and replacing the oil filter and oil with 5W-30 which was on the oil cap, I started it up, for the first 5-10 seconds it ran smooth like a ribbon, than my worse nightmare came back........tap....tap....tap., this time it was not as bad when ideling, but noticable when the engine was raised.
Now i'm considering pulling the heads off to see if there were valve damage.
Could it be a piston slap!?!?!.
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It very well could be piston slap. Only way to realy tell is mic the cylinder walls and see how bad the taper is toward the top of the cylinder(s).
This usualy will stop after 2-3 mins tops. I'd say about 50% of GMs I've worked on in the last 5-6yrs do this on start ups. After they warm up it should stop.
You also could have the valve lash wrong causing the lifters to bottom out. Which can pump them dry so not enough oil would flow to the top end to lubricate it.
Good Luck
06-07-2009, 06:59 PM
