Link G4 knock light issues

Hi guys, is my new Link G4 knock light defective or is the bosch donut style knock sensor installed in too noisy of an area as it's on the cylinder head (near coil and spark plug wire)?

Heads cam 2009 Corvette z06 ls7.

Essentially I am having my knock light flash red occasionally when the engine is idling and also when I blip the throttle (no knock can be heard nor is the factory ls7 e38 ecu detecting any KR, factory sensitivity in the tune's tables).

What is more strange as you will see in the video, is that the knock light won't flash red when I purposely knock on parts of the engine with a wrench.

I am using Resistor TR6 spark plugs, just swapped from non-resistor TR6 as I thought that was probably my issue but the same issues persist.

-supplied Bosch donut style sensor torqued to 15 ft lbs

-I tried 4 different circuits for my power source in case I had a noise issue on one of them, no change.

-With EMI reducing Faraday tape, I thoroughly wrapped the connections where the black and white knock sensor wires connect to the green and yellow knock light wires, no change.

-grounded the blue wire directly to the negative terminal of the battery versus my chassis ground, no difference.

-went from 91 octane to 97.5 octane fuel, no change as the red light still flashes from a mild throttle blip from a 900 rpm idle to 1500 rpm.

-disconnected knock light power and reconnected it while the engine was running to rule out any premature learning while the engine was still in crank mode, so it has "learned" with the engine at a stable idle.

The knock light is just below the "like" in the video. Engine is running in the video.

https://youtube.com/shorts/iSr5UPgkZic?si=YVUCVvNHCiK_7uGk

I think that's not a good location for the knock sensor. What happens if you use the factory location low down on the block. Will it fit with a longer bolt (so stack the OEM knock sensor and your Bosch sensor. Testing shows that this usually works really well.

That is a wonderful idea and I will try that. The factory location is way down below and away from the spark plug wires, awesome idea to stack the sensors. Will test this out, thanks.

Latest update: I found a monumental spot to mount the knock sensor. A tiny bit above the existing factory donut LS7 knock sensor on the driver's side, is a free hole that I bolted the knock-light's knock sensor to. So this location should be perfect. Torqued sensor to 15 ft lbs

The result is that it doesn't set the light off anymore with a throttle blip, nor randomly when idling, nor when revving down and coming to idle.

Just unsure why tapping with a wrench doesn't excite this knock-light.

Sensor loom is date stamped 28/10/2018 so the shop must have had this kit on their shelf forever, I just bought it a few weeks ago brand new.

I'm glad David was able to help you out!

Fortunately the knock detection system is a bit smarter than the wrench.

Hi Mike,

If you watched the video link I posted and your conclusion remains as above, then I will have to trust the Knock Light as I have never dealt with one before.

Thank you

This forum post has some insight into how the Link Knock Light works internally.

https://forums.linkecu.com/topic/10434-knock-link-light-question/

I did look at that forum post before joining here. Actually one of the members that posted in that link's post, was thinking that my loud wrench tapping should have been picked up by the knock light.

So this is unresolved at the moment, only thing I can do to test the light is to command a very aggressive ignition timing with insufficient octane, to induce an audible knock and then see if the knock light is being triggered. Just a bit shy doing that on an LS7 versus a $500 LS

The most important factor in generating knock is engine temperature. The hotter the engine / air temp is, the more likely to knock with lower octane fuel. We generate knock all the time when calibrating knock setup on standalone ECU. Your fear of a couple of seconds of knock at low load (2000-2400 RPM) is unwarranted.

What ECU are you using?

I have no light throttle fear, my fear is not knowing if the knock light should be picking up the hard tapping with a wrench or not. Stock ecu.

Please catch up with the thread as you are mentioning things that I have already addressed.

Hi Matt,

Just to follow up on your email.

I understand why you might be a little nervous; this is important tool, but rest assured both David and Mike are correct and are more than qualified enough to be trusted with the help and advice they are giving you here.

That is not what a knock sensor is for and it's not how you test one.

Your issue is/was not related to anything that hitting your engine with a wrench will identify or fix so it's best if you put that completely out of your mind moving forward =)

I hope that helps, and I am glad David's advice on sensor placement helped, too. This is a great webinar to watch in general if you haven't yet as well for anyone that stumbles on this thread: https://www.hpacademy.com/previous-webinars/203-ideal-knock-sensor-placement/

Thank you for the reply. I will trust my knock light a bit more now and I appreciate the clarification.

I recently joined this forum and because I don't know anyone but Andre Simon from the HPA videos I have watched, I simply wanted mutliple sources to reply with a similar conclusion before going with that conclusion as final. No disrespect intended, just a new guy here.

I come from the factory GM ecu tuning world and it took me a while to learn who to trust online. As I progressed through my tuning career, I realized there is a lot of misleading information online but picked up on the guys to listen to like Greg Banish.

Looking forward to learning from you guys. Although I've tuned for 13 years, I still learn something new every time. So to have seasoned tuners on here helping out, will probably get me out of some sticky tuning jams I know I will get myself into at one point.

You're all good mate, it's better to err on the side of caution than throw it into the wind with these things and the first steps are always the ones we analyse the most 😎

I hope you enjoy diving into the next challenge as you progress further and further into EFI tuning.

I don't know if you've taken the EFI Tuning Fundamentals course yet to prep for tuning, but it includes a section on knock which includes how to check your knock monitoring method by introducing knock in a deliberate but careful manner, to confirm that it picks knock up. While it's not for your exact combination of tuning software and knock detection device, the method is universal.

https://www.hpacademy.com/dashboard/courses/efi-tuning-fundamentals/the-tuning-process-understanding-knock/

The course continues with a section on optimizing ignition timing, which is one of the biggest tools in engine optimization as a whole, and knock avoidance.

I'll be going through the material thoroughly, a few rainy days coming up so I'll be glued to HPA. I appreciate the links.

Awesome. Enjoy.