K24/K20 Frank Knock from motor :/

[mikeyinid]

I recently noticed a knocking sound coming from the timing area of my engine. I only hear it through the passenger window at low rpm and low speed. It's barely audible at idle or just revving the car while it's stationary. I will attach a video that shows pretty well where you can hear it. I spoke to the guys at my local Honda/Acura shop briefly about it and they said a knocking rod will be picked up by the knock sensor. Not every knock but there would be a higher than normal knock count no matter what. I'm not seeing that. I have a knock here and there usually when the cams go from 20 degrees to 30 and always in the same fuel/ignition cell. So can be fixed.

My question is, would the knock sensor in fact pick up rod knock?

https://youtu.be/ayPSBcR-Yrw?si=sUInobsZcp3mrDht

[mikeyinid]

Over the last 4-5 days I've noticed a knocking sound coming from the engine. It's coming from the pulley/passenger/timing side. I can't hear it from the top with the hood open. I can hear it ever so slightly with my head down near the passenger front tire at idle. I can hear it while driving at cruising speeds in the 2000 to 3500 rpm range from the passenger window. I don't hear it through the drivers window while driving. Last night my wife drove the car while I was in the passenger seat and it's very clear. It increases and decreases with rpm. I don't really hear it while the car is stationary and revving the car, maybe very faintly. Definitely not as bad as I do while driving.

Here is what I've done recently, I noticed the sound shortly after:
I changed the PCV hose because the old one had a crack and it was making a hissing sound. Checked the PCV and the bearing moved freely so I didn't replace, hissing sound went away with new hose.
I also changed the oil for the first time. I put in amsoil 5-30 and noticed the sound almost right away which makes me wonder if the guy I bought it from had some sort of oil stabilizer in there to cover the knock up. Since changing the oil there is now an oil leak in the same area of the motor I haven't found yet (passenger side, rear of motor, maybe vtec solenoid?). Very small, maybe a drop or two overnight but it did not leak before the oil change.

My tuner sent me a cal and set the rev limiter to 8800 even though I told him multiple times I wanted a 8k redline. I'm not saying revving it to 8800 one time would cause a rod knock, but I noticed it immediately after. If there was already an issue it definitely didn't help the situation. Knock count was also through the roof on this cal, several hundred on a 20 minute drive.

The other thing is, the knock sensor isn't picking up anything out of the ordinary. I called the guys at Humble in Tulsa and they told me a knocking rod will definitely be picked up by the knock sensor. Not every knock, but a higher knock count would be present. I'm not seeing that.

There is no loss of power although the car is not running as smooth as it did. It's vibrating more and a little tougher to drive at low speeds. No detectable misfires, nothing in the logs. On a cold start I don't hear it, until the idle settles.

I've gone back through multiple cals and the issue is there on all of them. On the cal that came on the car it is almost undriveable now. Very jerky at low speeds. Lurches while cruising and holding rpm's. I always had those issues on that cal but they're worse now.

This is supposedly a fresh swap, the guy I bought it from said he did the swap in february. He said the JDM K24 he used had less than 50k miles. He said he replaced every gasket, brand new type s oil pump with all new OEM parts, new timing (chain, tensioner, guides all OEM), new dc 2.2 cams and full supertech valvetrain. I'm a little skeptical because I've found so many things that weren't done correctly, or doesn't line up with what he told me.

I had a mechanic listen to it, he said he doesn't hear a rod knocking just a really noisy valvetrain but the car was stationary and like I said, I can't really hear it when the car is stationary. My son and my wife can both hear it when they're passengers.

[mikeyinid]

This happened over a 72 hour period:
Changed hose from PCV to intake (temporarily resolved)
Changed oil
Next day got logs for new cal from tuner (logs attached to previous comment)
Noticed knock the following day.

[mikeyinid]

@Hondata, can you answer my question? The question being, will the k20z3 knock sensor pick up rod knock? I was told by a tuning shop that it would but I think you'd probably be the end all be all when it comes to this kind of info. Hopefully.

[Spunkster]

It can pick up many kinds of noises that should not be there.

[mikeyinid]

Thank you, Spunkster. I did figure the issue out. Failed Inline Pro timing chain tensioner. Got a new one in there and she is perfect.

[CalibratEd]

Thank you, Spunkster. I did figure the issue out. Failed Inline Pro timing chain tensioner. Got a new one in there and she is perfect.

Glad you were able to figure it out.

-Ed

[mikeyinid]

Thank you, Spunkster. I did figure the issue out. Failed Inline Pro timing chain tensioner. Got a new one in there and she is perfect.

Glad you were able to figure it out.

-Ed

Thanks Ed. You've been helpful. Much appreciated.

[CalibratEd]

Thank you, Spunkster. I did figure the issue out. Failed Inline Pro timing chain tensioner. Got a new one in there and she is perfect.

Glad you were able to figure it out.

-Ed

Thanks Ed. You've been helpful. Much appreciated.

No problem. I’m glad I was able to help troubleshoot. I hope you hear back from your tuner soon.

-Ed

[tobychap]

Your knock sensor may not detect rod knock, especially if it's subtle or at lower RPM. Rod knock, however, produces a lower frequency knocking sound, often between 1-5 kHz, which may not always trigger the knock sensor. Since you're hearing the noise near the timing area, you may want to inspect the timing chain, guides, and VTC actuator first before assuming it's rod bearings.

[tobychap]

Your knock sensor may not detect rod knock, especially if it's subtle or at lower RPM. Rod knock, however, produces a lower frequency knocking sound, often between 1-5 kHz, which may not always trigger the knock sensor. Since you're hearing the noise near the timing area, you may want to inspect the timing chain, guides, and VTC actuator first before assuming it's rod bearings.

Rod knock typically gets louder under load and doesn’t go away with RPM changes. If you can replicate the noise by revving in neutral, it’s less likely to be rod bearings and more likely something in the timing or accessory drive system.