Knock, Knock, Knock....

[Addicted To Boost]

What would cause a knocking noise (not deep, yet louder than just a tick) and smoke that smells like oil? I know its a vague description, but I need some ideas. I have good oil pressure and the oil level is good.

[Addicted to eaton]

Dropped valve? Scored main bearing (high miles) Not much to really work with lol.

[ManicMechanic]

Steady knock or intermittent?

[Addicted To Boost]

It can't hold an idle at all now and it sounds like its misfiring quite a bit in the exhaust. Cruising in OD at 55, the car just shakes, but the tach stays rock solid, I have a solid 40 PSI of oil pressure cruising around and 20 PSI at idle. Only has 129k... It JUST started doing this today too... Ran absolutely perfect prior to this.

[Addicted To Boost]

The knocking is steady and increases in frequency as RPMs increase, also decreases in speed the lower the RPMs are.

[Addicted to eaton]

dropped exhaust valve?

[ManicMechanic]

I'd be doing a compression test and pulling valve covers.

[birdman]

X2 on the compression test, sounds like a valve to me.

[Addicted To Boost]

Compression test reveals... 170 PSI on all cylinders... except cylinder #3. Cylinder #3 has 0 PSI and the spark plug is black and wet.

 

RIP TGP

[Addicted to eaton]

Now, Dont give up yet. Check to see how much damage.

[BXX]

if it actually dropped the valve the piston would shatter. I know, I have a l67 in my garage that suffered the same fate.

 

pull the valvecover and look for a broken valvespring. If so, replace it and see if you can't salvage the engine enough to make it run and quite down

[Addicted To Boost]

Wouldn't it have the same effect if a lifter broke or if I lost a cam lobe? Its pretty common to have cam lobes wipe out on TGPs...

[BXX]

yes, but valve springs break often too on Gen 2 660s

 

might as well pull the valve cover to get an idea of what is actually wrong.