ECMlink RESOLVED - Crazy knock under part throttle/low load/open loop

[dwb]

I've attached a data log of my commute to work this morning.

I've been experiencing lots of knock under low load, part throttle, ~2k-3k RPM, and usually open loop. In this log, knock continues into closed loop for a bit. I have to release throttle and roll back into it for knock to stop, and even then it doesn't always stop. This same behavior happens every time the engine is cold, up until either closed loop or full operating temp. Once at full operating temp I primarily see knock under higher load/RPM/throttle as expected which you can see later in the attached log.

Stock fuel system, 91 octane. Stock MAF. Mostly stock car except ECMLink and MBC. Running stock 2g timing maps on a fresh 6bolt with 2g pistons. No other changes to ECMLink from a stock 1g config. No boost leaks, no exhaust leaks. Lifters do not tick (3g revision). I do notice some extra engine vibrations around 3k RPM, which I speculate might be a very slightly bent CAM or sprocket (these CAMs came from a 1g that was rolled over/landed on top of the hood and broke one sprocket). I'll be swapping CAMs and sprockets in the upcoming week(s) to verify this speculation.

I'd appreciate it if someone could take a look at the attached log and let me know if there is something amiss that can be adjusted. I'm an ECMLink noob so please forgive me. Hopefully I've captured the pertinent fields and values.

 

[dwb]

Issue remains after re-torqueing the knock sensor. It wasn't really that tight to begin with. So I did finger tight and then about an eight to quarter turn from there.

Onto HLAs...

 

[Stapl3]

Did you try the file I made for you?

 

[dwb]

Did you try the file I made for you?

Not yet, sorry. I'm hoping to eliminate this phantom knock first then have some fun with the tune. I do appreciate the work you put into it and I will definitely be using it in some capacity.

I had another thought about this phantom knock to determine if it is indeed mechanical noise. Since I can easily reproduce the issue without getting into boost or anywhere near actual knock, I could remove the knock sensor from the block, tie it up to the firewall and wrap it in a rag. Wire the wastegate open and go for a test drive. If I see any knock at all, I either have a faulty knock sensor or some sort of electrical interference/noise. Does the knock sensor require an electrical ground?

BTW, new HLAs have been ordered.

 

[Stapl3]

Not yet, sorry. I'm hoping to eliminate this phantom knock first then have some fun with the tune.

Sigh.
I feel loading my file will eliminate the knock. You're a goosechase looking for physical noise when really your timing is absurd^2.

 

[dwb]

Sigh.
I feel loading my file will eliminate the knock. You're a goosechase looking for physical noise when really your timing is absurd^2.

I apologize, I misunderstood the purpose of your file. I thought your tune was more aiming at the higher load/RPM (true) knock. Not the 2000-3500RPM range where I'm getting PK. I'll have to upload it and see what it does.

 

[Stapl3]

Rad, would love to see if it works or at least a step in the right direction. I'm going against the consensus here and think the knock is legit and you do not have PK.

 

[We're on Boost]

Sure, it'll be interesting to see what it does with less advanced timing.

 

[dwb]

Alright, here's a log with @Stapl3's maps. I'll take another one in the morning with the same route as my first logs.

BTW, It feels like a dog with these maps.

 

[We're on Boost]

Alright, here's a log with @Stapl3's maps. I'll take another one in the morning with the same route as my first logs.

BTW, It feels like a dog with these maps.

This log starts at 153 degrees already. We wanted to see it at lower temps like below 140, from a cold start like your May 17 log. Because that's where the long runs of 43 raw were (the max possible reading).
But yeah this is pretty awful still at the high temps.

 

[dwb]

Another log attached. This is from a cold engine, @Stapl3's timing maps, same route like the one on May 17th. I've reduced my knock sensor control to 2500RPM and 10% throttle.
Massive knock detected starting around 225 seconds. I had to keep letting off but it kept pulling 15deg

 

[danl]

You asked a question about removing the knock sensor and zip tying it to the firewall earlier. You can do this and it works. Guys would do this 20+ years ago and they would usually smoke the engine the very first pass. You’ve been warned, keep it in vacuum. Still, it’s an acceptable test to determine if the knock is mechanical noise from the engine.

 

[dwb]

You asked a question about removing the knock sensor and zip tying it to the firewall earlier. You can do this and it works. Guys would do this 20+ years ago and they would usually smoke the engine the very first pass. You’ve been warned, keep it in vacuum. Still, it’s an acceptable test to determine if the knock is mechanical noise from the engine.

I fully understand the repercussions of "disabling" the knock sensor this way. I'd just wire my wastegate open for the duration of the test.

 

[danl]

I think it was also a good suggestion to try the lower timing maps. That is very easy to do and the test adds further data to your quest for answers.

At this point it will be interesting to see what the new hla’s do. 85% of the time they work every time. Hla’s are maintenance items on these cars. They last 60-100k for me.

 

[dwb]

I think it was also a good suggestion to try the lower timing maps. That is very easy to do and the test adds further data to your quest for answers.

At this point it will be interesting to see what the new hla’s do. 85% of the time they work every time. Hla’s are maintenance items on these cars. They last 60-100k for me.

Indeed it does, which I didn't fully grasp the point until yesterday

HLAs arrived today. I decided to go with the Topline brand. With a long weekend coming up, potentially I can get them swapped out then.

 

[1990TSIAWDTALON]

You asked a question about removing the knock sensor and zip tying it to the firewall earlier. You can do this and it works. Guys would do this 20+ years ago and they would usually smoke the engine the very first pass. You’ve been warned, keep it in vacuum. Still, it’s an acceptable test to determine if the knock is mechanical noise from the engine.

DO NOT disable the knock sensor in anyway. I set my sensor at a point WAY beyond my max RPMs to "test" what I thought was PK, I smoked that motor just like was stated. It got me home but had 2 melted pistons so a full rebuild was needed.

 

[dwb]

DO NOT disable the knock sensor in anyway. I set my sensor at a point WAY beyond my max RPMs to "test" what I thought was PK, I smoked that motor just like was stated. It got me home but had 2 melted pistons so a full rebuild was needed.

Ouch! Was this the engine you had running earlier this year?

N/A 4g63's don't have knock sensors, so as long as the wastegate is wired open it's essentially N/A. That's my plan if new HLA's don't fix my PK issue. I need to know if it's mechanical noise or not. I understand the risks, but hopefully it doesn't come to this.

 

[1990TSIAWDTALON]

Ouch! Was this the engine you had running earlier this year?

N/A 4g63's don't have knock sensors, so as long as the wastegate is wired open it's essentially N/A. That's my plan if new HLA's don't fix my PK issue. I need to know if it's mechanical noise or not. I understand the risks, but hopefully it doesn't come to this.

Good, no knock sensor. No the car that happened to was my 92 Auto car when it was stock. I put Link in it and was getting some early knock and couldn't for the life of me figure out what was the issue so I set my sensor up around 8000 and went out and did a pull. That was all it took. I toasted 2 pistons and that is what made me upgrade that car. I had thought about leaving it original and was fun to drive but needed a little more get up and go so I was turning the boost up on that 13b hairdryer when it happened. There may be mention of it in that cars BIO, I can't remember if I announced to the world how dam STUPID I WAS.

 

[danl]

I also smoked a built motor when I disabled the knock sensor in code. This is more for the people who read this in the future.

 

[1990TSIAWDTALON]

Sorry @danl
I made a mistake. We both own it.

 

[dwb]

OK, new HLA's installed. Doesn't seem to be quite as "chatty" in the top end. Fixed a few boost leaks too. Looking better!!!
Log attached, cold start, same drive. Knock disabled below 2500RPM and 10% throttle.

 

[We're on Boost]

Looking better!!!

Yeah! All that 43 raw stuff is gone. Now all I see is what looks like real knock at high load, at 501 and 639 sec.

 

[danl]

Things look better on the phantom knock front. You still have some periods of knock and they look real. Even early on in the log you get 2-4 deg of retard and it appears to be due to too much timing. As you get the car warm and do a 1-2-3 gear pull, that looks like real knock as well. Again, the timing advance appears to be aggressive.

 

[danl]

Use the global sliders to remove 5 degrees of timing from 2500-redline. Take another log and post the file. I’d like to see a change before making suggestions.

 

[dwb]

It does look better, doesn't it? It feels like a different car, much more responsive. @danl I'll give your suggestion a try next chance I get. Thanks!

 

[Blinkyblinx9]

That's awesome, seems like noisy HLAs or some were bleeding off too much oil pressure. I'm interested to see if that had any effect on head pressure now that things have quieted down.