HELP - Got a LOUD knock

[Bigdough666]

Jus finished racing some foo in a Thunderbird, whooped his ass. As I slowed I heard this

KNOCK, KNOCK, KNOCK

So far, this is what I know. Its definately RPM dependent. I still have some power, but not much. Oil level and pressure is perfect. 2000 miles on a fresh rebuild, Clevite 77 bearings, ARP everything.

The noise appears to be coming from the top of the head, right next to the turbo. And its LOUD as hell. Can u spin a cam bearing? What else could it be? I'm really hoping its not a rod bearing, as it sounds like its NOT in the bottom end. Any ideas? I need some help, Im scurred.

 

[GrimJack]

Broken valve?

There are no bearings on the cams... and they wouldn't make much noise anyhow, they just spin, nothing like the rod that is moving up and down with the weight of piston, rod, wristpin, etc, not to mention the force of the combustion pounding on it.

 

[Bigdough666]

I wasnt sure. I didnt think there were, but I dont know wha could make so much noise on the top of the head. Im sure its on the top, sounds like its right under the valve cover. Im prolly gonna pull it off tomorrow to take a look.

Thanks, keep the ideas coming.

 

[MKIIIChucky]

Jus finished racing some foo in a Thunderbird, whooped his ass. As I slowed I heard this

KNOCK, KNOCK, KNOCK

So far, this is what I know. Its definately RPM dependent. I still have some power, but not much. Oil level and pressure is perfect. 2000 miles on a fresh rebuild, Clevite 77 bearings, ARP everything.

The noise appears to be coming from the top of the head, right next to the turbo. And its LOUD as hell. Can u spin a cam bearing? What else could it be? I'm really hoping its not a rod bearing, as it sounds like its NOT in the bottom end. Any ideas? I need some help, Im scurred.

look down at your crank pulley , your crank key might be cracked , see if the crank pulley moves around when u rev up the engine ... Happend to me on the engine that came with the car when i bought it, any ways i thought it was the timing belt or somthing on the head but it was the crank pulleys key thing cracked into pieces when i pulled off the pulley, but it could be somthing else thats wrong with ur car !!! .good luck.

 

[MKIIIChucky]

look down at your crank pulley , your crank key might be cracked , see if the crank pulley moves around when u rev up the engine ... Happend to me on the engine that came with the car when i bought it, any ways i thought it was the timing belt or somthing on the head but it was the crank pulleys key thing cracked into pieces when i pulled off the pulley, but it could be somthing else thats wrong with ur car !!! .good luck.

ohh yeaa, when my crank pulley was knocking on the lower part of the engine , my oil pressure n everything else was all fine

 

[Bigdough666]

I never even thought of the crank pulley. I'll check it out.

 

[Bigdough666]

Ok, NOT the crank pulley.

 

[Dirgle]

Is it a knock or a tick? If it's more of a tick it's possibly an exhaust leak.

 

[Bigdough666]

Nah, its a LOUD knock. What gets me is that it sounds like its right under the valve cover. I dont know wha it is.

 

[MKIIIChucky]

Ok, NOT the crank pulley.

kool, good luck with finding out the problem

 

[IJ.]

Might have spat a valve shim out

 

[Bigdough666]

Thats the 2nd time Ive heard that, I HOPE thats it. Toyota adjusted my valves (shimmmed em too) so if it did chunk one, they'll fix it.

 

[shaeff]

maybe one of the cam caps came loose? if it were that, it could bounce up and down and make a knocking sound...

-shaeff

 

[TONY!]

From what I gather, if you take out the spark plug wire the cylinder with the knock, the sound would greatly decrease if it is indeed a spun bearing.
(I am pretty sure I read that a couple of times, but I have no first hand experience wiht it.)

Bigdough666, if I am not mistaken, you had rodknock before, or am I confusing you with someone else?
Because if you did have a case before, did you replace your connecting rod? Did you have the new oil clearance between the bearings and the crank measured? Many times the connecting rod for that cylinder that has a case of rod knock becomes unusable because the bearing tang notch is damaged.

 

[Bigdough666]

Na it wasnt me. BUT IT IS NOW.

ITS MUTHAFUCKIN ROD KNOCK.

Turns out, the oil was fuckin low. That + racing = ROD KNOCK.

Gonna be tearing it down this week. Hope I didnt jack the crank. :3d_frown: