knock low load

[Edain]

Hi team.

I have the following question.
Analyzing my car's engine logs, I see a knock of 8.0 at low load. For example, if I shift from 3rd to 4th at 2300k RPM, the knock increases for a moment. At high load, the knock doesn't increase; it stays at 0.79. I want to know what's happening. Maybe it's a false knock. I should clarify that the knock doesn't increase at all at high load. I'm sharing my log and tune details.

My car's specs:
- HPFP updated.
-CPE CAI
- ETS big intercooler.
-Downpipe anda catback 3in
- LTR7IX-11 spark plugs.
- Smoke vacuum test: Pass.

Thanks!

[mituc]

You may have an intake leak (I know you said you passed the smoke test but the logs show a different story), and once you fix that see if anything changes. Right now the combined fuel trims are around 12-16% and the very small boost time you had in this log shows that the leak may be before the turbo.

[Edain]

Thanks for replying. Today I'll disassemble the entire intake system before the turbo to make sure it's properly adjusted. I'll come back and post the results. Thanks

[Edain]

Hi Mituc. I've checked all the connections and hoses, and everything seems fine. I did another smoke test and I see a small leak at the EGR gasket. Do you think that could be the problem?

[mituc]

Hi Mituc. I've checked all the connections and hoses, and everything seems fine. I did another smoke test and I see a small leak at the EGR gasket. Do you think that could be the problem?

Any leak could be the problem. So fix anything that you can find.
Also, from your log it's hard to determine if the leak is on the boost side or on the vacuum side because you barely had any boost action in that log, and it was around 2500rpm. A leak on the EGR pipe would result in a boost leak and I could not see that in your log, but on the other hand there were too few lines to draw a proper conclusion. ...thus my conclusion that your leak is on the vacuum side.

You can download and use this dashboard preset for your next logs: https://www.dropbox.com/scl/fi/s7e5zpu3 ... e98oc&dl=0 - it has everything that we need in pretty much any situation.

[Edain]

I'm happy you can help me. How do you need me to send you the log? Is it normal driving, or something specific?

[CrazyCanadian]

Hit the log button once the motor is warmed up and go for a little drive. Log the whole drive. You want different throttle positions, try and stretch out the light throttle rpms.. Do a couple WOT runs if things feel safe.

[Edain]

Here's my log: note the knock increases when the a/c is on and also if I press the accelerator from 2 to 2.5k rpm.

[mituc]

Ok. So every single time the ECU commands some cam timing, knock retard follows shortly after. Every single time, no exception.
The AC may increase the load a bit and the need for the ECU to command more cam timing.
So get the car checked and make sure the AC pulley bearing is not dry and about to fall apart, and obviously also check the timing maybe you have to replace it.
Also, you clearly have a leak somewhere, looking in the same log when the car speed is 0 (meaning you're idling) the AFRs are all over the place which is somehow understandable considering how the fuel trims look.

[Edain]

I forgot to mention is that this only happens during the day, when the temperature is 36 degrees Celsius. It doesn't happen in the morning or evening because the temperature drops. The maximum increase is 2 degrees. Could it be excessive heat under the hood? As I said, here in my city there are stop signs on every corner and no constant speed. I have a large ETS intercooler.