Hi folks. I was doing a valve clearance adjustment the other day as there was grinding noise when engine braking. While doing that I noticed noise, If you listen at the 2-second and 46-second marks of the video, you’ll hear a metallic knocking sound. I’m not sure how to describe it—it’s like a blacksmith hammering iron. During this timeframe, the crankshaft completes exactly 720 degrees of rotation. Also, I over-torqued the valve adjustment bolt. How can I check if anything needs replacing? It is a 2003 JDM F20c. Any advice is appreciated thank you!
https://drive.google.com/file/d/1-7p...ew?usp=sharing

 

hard to tell much from that. But grinding noise during engine braking would not be due to valves being out of adjustment. Really would need to know more about that or be able to hear that happening to be able to say much about what it is.

On the adjustment nut, how much did you over torque it? Does it still thread smoothly?

 

Hi engifineer, thanks for the reply. https://drive.google.com/file/d/1YwU...ew?usp=sharing
This is an audio recording I made earlier while driving. I'm not sure if it tells any story, recording taken in the mesh pocket on the front passenger side.

I'm not sure by how much I over torqued it as my seized up torque wrench caused it. I estimate I applied around 40 Nm. It still threads smoothly though I reckon.

 

If it can be loosened, and still threads up and down by hand once loosened, its totally fine.

You didn't apply enough torque to damage the structural integrity of the stud.

Its that feel we build from experience, what feels like not enough, or too much, torque for a given fastener. Something seems wrong, stop, think, check.

You did that. Congrats!

There is a level beyond that, where you can actually feel the spot where you've applied correct torque. Mechanics feel that can be as accurate as a torque wrench. One can actually feel that moment the bolt begins to stretch. Feel the change in degrees of turn vs resistance. From a steady increase in resistance logarithmicaly proportional to degrees of tightening, to a more steady resistance.

 

That seems twice the torque needed for almost everything under the valve cover.

We've had a rash of over-torqued bolts (OK, two) today both caused by the wrong or known broken tools or not paying attention. Our engines have aged to the point they're not replaceable and parts are scarce. I fully understand the satisfaction of these DIY tasks. The Service Manual is conservative but don't rush or take shortcuts. When in doubt RTFM.

-- Chuck

 

I used to trust tools far more than I trusted myself. Though my questioning spirit is still alive and well, and I managed to save the engine lol

 

Can't agree more. Cheers Chuck