SScooter

Just bought an AWD TBSS really cheap because the motor was knocking but I've never heard one like this. Upon initial startup for about a second and goes away. Then it starts knocking very quietly and slowly gets louder and louder does this for about 20 seconds then goes away for about 20 seconds and repeats the cycle. Any ideas?!

ysb02

No codes thrown? My AWD TBSS was getting knock btw on stock timing + 93 octane.

SScooter

No it never did throw a code im stumped because as far as I know if it was a spun bearing the knock wouldnt come and go like that.

Bill00Formula

iTrader: (4)

I bought a truck (non LS) that was knocking on occasion and when I took the motor apart there was a ton of slack in the timing chain. Not sure if the symptoms were the same as yours.

By the way I have a traiblazer ss with 94,xxx miles (wife drives). Still runs well.

Pwebbz28

iTrader: (31)

Bad lifter? My buddies TBSS had a lifter go bad and take out the cam at 50k miles. Bone stock truck that his wife has driven since new