I want everyones input on loud ticking sound when you start the car.

Just recently and not often when I start the car, I head this loud ticking sound (3 ticks) the sound if I could describe it is almost like a hammer against metal.

My buddy thinks its the timing chain/tensioner. If it is, did GM release a new version or heavier duty for a tensioner?

 

There is an updated version. Crateenginedepot sells it

 

i wouldnt keep driving it if i were you, i would agree with your buddy that its the timing chain tensioner. if it were to fail. you could end up like 1LowLS and having to do alot of work.

 

If it happens only on cold starts (ie. when you haven't driven the car for several hours) then its definitely the tensioner.

I had the same symptoms before mine was replaced

 

Check ya oil first see where ya at the factory tensioner was spring loaded pressure to the timing chain the newer ones work off oil pressure

 

Hmmmm mine has done this forever. Should probably change it soon I guess...ehhh

 

Just an update it was the actuator for the air circulation. Which is a big sigh of relief. I will be saving up to do the tensioner

 

I have something similar...
When the engine is cold, sometimes it makes a thwaack sound about a half second after starting up.

I guessed it was the AC clutch popping because it usually happens when I used the AC the day before, and shut the engine off with the AC engaged. The next morning, the AC buttons are turned off before starting up, but I think something mechanical is already engaged and when the belts spin, it makes a thwaack sound as it disengages.

I asked about this when I had my water pump replaced. They said the chain looked fine, and the tensioner is a non-wear/ not replaceable item. I thought it was the timing chain too.

I figured it was just noisy, but perhaps it too is something to do with the AC/ air ducts.

Mine is an 07 LS, and they did show on the computer that the tensioner is a non-wear (probably not the right term), non-something.... But they/ it said it is part of the motor and can't be taken off.

I hope it is not my tensioner and await a head failure...