2006 4.2 Trailblazer Engine noise/knocking - VIDEO and SOUND

[CASHKJ]

Here is a video of what the engine in my TB sound like any ideas.

Thanks!


[video=youtube;ABzWUrhlgT0]http://www.youtube.com/watch?feature=player_detailpage&v=ABzWUrhlgT0[/video]

 

[CaptainXL]

That's rod knock I believe. Drain oil and check for metal or send to a lab for analysis to check for bearing material. Sorry.

 

[Harpo]

OUCH that doesent sound to good.

But it seems to be louder at the back of the Engine.

And it is kind of strange that it suddenly stops for a while.

The first thing i comes to my mind is, check the bolts to the torque converter to see if one of them is loose.

I had that problem on a previus car , i feared the worst but it was only one bolt that came loose.
That sound also come and goes as the bolt turns.

That bolt caused a crack in the flexplate, but i rather have that than a bad rodbearing.


Just an idea to check this, its a lot easier than a rod bearing.

Hope for the best

 

[gmcman]

Almost sounds too slow for a rod, hard to say though. Sounds like it's in the head.

Checking the oil will tell a story. What you need to do is loosen the coil harness fom the coil packs while it's running and see if the knock changes at the moment you pull the harness.

May throw a code but just pull one at a time for a few moments.

 

[gmcman]

Once you test the individual cylinders and if the knock persists, I would get a quality oil pressure gauge and check the pressure at the sensor tap and note the pressure when the knock is present.

Could be an oil starvation issue but just a thought.