40 miles on new engine, now have knocking from the front....

[WSLN 6]

What happened?
There is a knock coming from the middle of the engine, near the front. It varies with rpm, and is not coming from the valvetrain. At idle it is barely audible, but just touch the throttle, and it is quite loud.
Any guesses?

 

[VadersV6]

Is the crank sensor tight and have equal clearance on both sides of the interrupter ring? I had this and turned out to be the crank sensor had come loose and the ring was tapping into it. Also get a hose and listen to the cam sensor and wherever else you think the sound may be coming from.

 

[bilt2run]

ahh chit

Text book description of a rod bearing.

 

[KevinB]

Text book description of a rod bearing.

Sounds like what the motor in my car currently does. After dropping the pan and pulling all the rod caps, I found a bearing sitting on top of another I vote rod knock too. Sorry

 

[VadersV6]

Its also a textbook description of a loose crank sensor. Also a bad cam sensor. Also a bad idler pulley. Also a bad water pump. Also a bad oil pump....lots of things. Dont be so doomsdayish with the guy, you're scaring him!
A deep sounding, heavy thunk thunk thunk would be a rod. A tak tak tak sound isnt likely a rod.

 

[Russ Merritt]

DOOMSDAY IS HERE!!!!!!!


Where's the Grim Reaper icon????

 

[Brer Rabbit]

Please keep us posted...

Now u got me real nervous... Can u please give a detailed account of what u did from start up til now. I just got mine started and drove it around the block once so far. I know I have an exhaust leak, but I would go after my engine builder with a bat if something went wrong in my motor after 40 miles. Except for the turbo we have similar set ups, I hope its not cam related.

 

[chrisgarrett]

Use a stethescope or a screwdriver to your ear to listen to the cam sensor. If that isn't the source, take off the belt and run the car to see if it is anything on the belt: tensioner, alternator, compressor, etc.. Even a belt that is too long can make a tapping noise. As mentioned above, check the clearance on the crank sensor. If it's none of those, take off the valve covers and see if all of the lifters look the same and the pushrods are turning.

 

[onefastcar]

Could be many things bad spark plug wires can make this sound be methodical while checking this out.

 

[WSLN 6]

Thanks for the info guys! I am not scared, just dissapointed I guess. The car had one oil change so far, not a spec on the drain plug. Sounded fine until after a few bonzai highway runs. Felt surprisingly stable past 150....lol Love that cam!

 

[Brer Rabbit]

Past 150?!!!

Im startin to get excited as we have the same cam, I copied this combo and hope it does as well as the untuned 11.20 pass that impressed me. Im sure with that big ass turbo u have ur car will go 10.50 without pushing it. Is the bottom end stock?

 

[KevinB]

To eliminate some things, this is what I did:

Take the belt off. Run the car without the serp belt. This will eliminate all belt driven devices (water pump, ps pump, alt, idler pulley.) Do not let the car run for too long.

Take off both valve covers, make sure none of the rocker shafts are broken. Also look for broken v-springs.

Check cam sensor. Swap it out if you have another.

Check crank sensor. Make sure it's tight and you can fit a matchbook between the sensor and both sides of the interuptor ring.

Has your oil pressure gone down?

Does the oil have lots of metal in it? A spun bearing will leave bearing material behind.

Remove oil pan, remove rod caps....hopefully you will not find what I did.

Good luck!

 

[WSLN 6]

Took the valve cover off, the oil is a lovely metallic gold color.......

 

[blacksix]

Oh . . . :frown: . Been there, done that. 300 miles last time.

 

[WIKEDV6]

Im startin to get excited as we have the same cam, I copied this combo and hope it does as well as the untuned 11.20 pass that impressed me. Im sure with that big ass turbo u have ur car will go 10.50 without pushing it. Is the bottom end stock?

Allow me to give you the detail; That was untuned 11.20 @119mph on pump gas and 19 psi boost shifting only at 4900 rpm

Prasad

 

[Silver Fox]

I realize this isn't at the front of the engine, but check your torque convertor to flywheel bolts. If they are loose, the make a knocking noise when you tip into the throttle. Might be worth checking. You don't need to ask me how I know.

I also had a Monte Carlo years ago that the flyweel cracked on it. Sounded like my engine had thrown every rod, but turned out to be a simple fix.

Rob

 

[chrisgarrett]

I realize this isn't at the front of the engine, but check your torque convertor to flywheel bolts. If they are loose, the make a knocking noise when you tip into the throttle. Might be worth checking. You don't need to ask me how I know.

I also had a Monte Carlo years ago that the flyweel cracked on it. Sounded like my engine had thrown every rod, but turned out to be a simple fix.

Rob

If he has gold metal in his oil, it ain't the converter bolts.

 

[Silver Fox]

If he has gold metal in his oil, it ain't the converter bolts.

I missed that part!

 

[Jerryl]

Took the valve cover off, the oil is a lovely metallic gold color.......

If he has gold metal in his oil, it ain't the converter bolts.

Agree. Dumb question; Should the oil filter not have prevented this from making it to the valve cover? Or is the thread starter simply implying "Std clean oil metallic gold color"?

 

[WSLN 6]

The oil wasn't metallic when it came out of the bottle......lol
I have a biggie filter, plus a remote big filter for the turbo.
I am going to drop the oil right now and see what it looks like on a larger scale.