So after all this time, does anyone know 100% for sure what is causing the knock

[bast525]

I have had an AP from day one, and also been tweaking with ATR since the day it was available, but really, this question goes for anyone who has the ability to tune their Speeds. I would think... I would HOPE that by now someone has learned or proven at least something about what is really going on with this weird, bipolar little engine and causing random stutters, knocking, big puffs of smoke, and blown engines. I have been reading through threads but haven't really seen anything more than random people passing on random speculation.

I can personally say that I have tried many of the 'tricks' that should have logically worked (or that would.. you know... work on ANY OTHER CAR). I have tried adding fuel. I have tried lowering boost. I have tried retarding ignition timing. I've swapped to colder plugs. I've checked and rechecked for boost leaks.

99% of the time, I can nail the throttle at any RPM in any gear and have no problems. But at random times, I will go WOT from a cruise, car will buck/stumble, sometimes badly, with a sound like a light backfire from the exhaust, I will usually see a big puff of smoke (hard to tell but it looks greyish to me which is kinda scary), and usually will see big KR numbers on the AP.

I can go out, find a nice deserted area, and do pull after pull after pull with no issue. But when I'm just driving around normally, and then need to speed up suddenly for some reason, this is more often than not when I have this happen.

The theory that SEEMS to fit most is the idea that gunk is getting sucked up from the PCV or whatever during normal driving, and then suddenly getting on it causes this stuff to get sucked up and choke the engine. But that's just one of the plausible theories out there. I am a po'bastard and have yet to be able to install any kind of PCV fix, catch can, or everyone's favorite meth injection, which, if the gunky theory is correct, I guess this is the only way to fix this. But for self-tuners... have any of you guys found, for 100% certain, another culprit that I should be looking at?

What have we as a group learned, what do we know for sure, and what are we still not sure about?

EDIT: oh yeah I should mention... I am not even at ALL concerned about part throttle or cruising KR anymore, and this is not the concern of my post.

I've definitely read enough info that suggests that this really is nothing to be worried about.

I am talking strictly about WOT knocking, and not even necessarily KR on the AP, but that gut wrenching stutter, big puff of smoke, and sounds like an engine about to convert internal parts to external parts...

[DCLXVI]

FMIC, oil catch can, MAF mesh, and a protune.

[bast525]

Originally Posted by DCLXVI FMIC, oil catch can, MAF mesh, and a protune.

That's it? that's the guaranteed recipe for no more knock or no blown engine? What about meth? What about removing the balance shaft? Who's having the most success with tuning themselves using ATR?

Not being sarcastic... these are all things I've read that someone or other has suggested COULD be causing the problem.

I just got done reading through SLS MS3's blown engine thread... I want to think that because I am so lightly modded (intake and AP) that I am safe, but when I am leaving a light or whatever and get on it in 1st/2nd/3rd gear, and the car bucks and I hear sounds no engine should make, and a big puff of smoke out the back... I don't think I'm safe either way.

[boosted3]

maf mesh is bull shit

[smakdown61]

I drive 120 miles a day roundtrip for work and I just ignore the cruise knock. Its just the ecu trying hard squeeze out as much timing as it can for good gas mileage. How did I confirm this? Here are some observations:

1. The knock doesn't just show up then disappear. It will throw 4 or 5 degrees (supposedly) and slowly work its way down to zero like its testing itself. 4 or 5 degrees of retard when ur running 40+ isn't shit and you won't feel it.

2. Instead of lifting when I see KR I started to just let it ride. After a few times of rolling down to zero, it actually stopped KR'ing at cruise. When you lift, it doesn't give the ecu a chance to learn so it keeps trying.

3. According to the mazda DISI training doc, the ecu can only pull up to 6 degrees of timing during an actual detonation situation. I've seen 6+ kr during 80mph cruise quite a few times without the car stumbling or hesitating.

[bast525]

Smak... thanks man you actually pointed out a glaring error in my original post... I shoulda mentioned I am not at all talking about or worried about PT KR... OP edited for clarity

[smakdown61]

Originally Posted by bast525 Smak... thanks man you actually pointed out a glaring error in my original post... I shoulda mentioned I am not at all talking about or worried about PT KR... OP edited for clarity

Ah I see what you were saying. Yeah its certainly possible if you aren't running a catch can that under boost its forcing that gunk into your combustion chamber. Honestly, after using ATR to adjust my tune and adding an occ and one step colder plugs I don't have any WOT knock at all.

[2007speed3]

All of a sudden for the past 2 days i would get 3-6kr when driving like a granny not in boost just cruising along.

I decided that to reload the map and of course that stopped it, but im sure once the computer relearns again it will reappear.

Originally Posted by smakdown61 Ah I see what you were saying. Yeah its certainly possible if you aren't running a catch can that under boost its forcing that gunk into your combustion chamber. Honestly, after using ATR to adjust my tune and adding an occ and one step colder plugs I don't have any WOT knock at all.

I cant say the same for me, i have both 1 step and 2 step colder plugs, knock doesn't change.... i still get 1.8 2.3 3.5 4.6 6.3 or whatever knocks at the most random fucked up times, ie. no boost leaving a stop light just gradually adjusting my speed 5 plus mph or letting off the throttle at 3100-3500rpm suddenly.

[slo4now]

I dont have knock, cant help you here.



Try TORCO

[smakdown61]

Originally Posted by slo4now I dont have knock, cant help you here. Try TORCO

Do you monitor with a dashhawk?

[boosted3]

I get crazy random knock sometimes just crusing like u said dosent effect anyting or i dont hear anything,but somedays it wont even kock at all,I dont even worry about that anymore.Unless im wot in boost thats the only time u really wory about that knock....

[jahman]

Originally Posted by smakdown61 I drive 120 miles a day roundtrip for work and I just ignore the cruise knock. Its just the ecu trying hard squeeze out as much timing as it can for good gas mileage. How did I confirm this? Here are some observations: 1. The knock doesn't just show up then disappear. It will throw 4 or 5 degrees (supposedly) and slowly work its way down to zero like its testing itself. 4 or 5 degrees of retard when ur running 40+ isn't shit and you won't feel it. 2. Instead of lifting when I see KR I started to just let it ride. After a few times of rolling down to zero, it actually stopped KR'ing at cruise. When you lift, it doesn't give the ecu a chance to learn so it keeps trying. 3. According to the mazda DISI training doc, the ecu can only pull up to 6 degrees of timing during an actual detonation situation. I've seen 6+ kr during 80mph cruise quite a few times without the car stumbling or hesitating.

Smak, what about the shift to the next gear and just as you let off the clutch KR appears. Do you think thats the same thing? Or maybe its some kind of false alarm or drivetrain noise as it gets loaded up again as you shift into the next gear. Or perhaps my engine is self destructing slowly.

[nytmar3]

Turn off the KR monitor on your dash hawk......no more knock. If your not hearing it, I wouldn't worry about it.

[bf360]

Originally Posted by boosted3 maf mesh is bull shit

holy shit the first post i actually agree with you on

[DCLXVI]

i wasnt really saying that was the solution, i just gave 3 options which claim to aid in no more knock

[Haltech]

Originally Posted by smakdown61 I drive 120 miles a day roundtrip for work and I just ignore the cruise knock. Its just the ecu trying hard squeeze out as much timing as it can for good gas mileage. How did I confirm this? Here are some observations: 1. The knock doesn't just show up then disappear. It will throw 4 or 5 degrees (supposedly) and slowly work its way down to zero like its testing itself. 4 or 5 degrees of retard when ur running 40+ isn't shit and you won't feel it. 2. Instead of lifting when I see KR I started to just let it ride. After a few times of rolling down to zero, it actually stopped KR'ing at cruise. When you lift, it doesn't give the ecu a chance to learn so it keeps trying. 3. According to the mazda DISI training doc, the ecu can only pull up to 6 degrees of timing during an actual detonation situation. I've seen 6+ kr during 80mph cruise quite a few times without the car stumbling or hesitating.

This is the answer and you can verify this simply with a dashawk if you are in doubt. You can set the visual alert for knock and do color changes for each range of knock (degrees) ... Mine starts off Dark green and works itself to yellow. What is funny, no one ever believed me that part throttle knock is something to be worried about. Its nothing more then the computer trying to adjust timing to match the best mpg... Ive also verified this with the MPg computer on the car.. As your phantom knock begins, look at the mpg readout and watch it adjust

[Deadman]

it is or is not somthing to worry about? lol

[Frequentflyer]

Originally Posted by Deadman it is or is not somthing to worry about? lol

It is not something to worry about. Mine only does it during cruise in 5th and 6th gears. 5th more than 6th actually. I'll get a very infrequent .3-.7 during WOT, which I usually can't reproduce from one datalog to another.

I was getting WOT stumble and it turned out to be my plugs. I was using ITV24's and had about 20k miles on them. Replaced them with ITV22's and no more stumble. I'm going to start changing my plugs every 6 months. I put 24k miles a year on the car. For $36 a set, it's a no-brainer. This car is not easy on spark-plugs at all. You can't go 100k miles a set of plugs with this car like you can in a Honda motor. A "wrenching stutter and a big puff of smoke" doesn't sound like a pre-ignition problem to me. It sounds like spark blowout, but that's just my opinion. The puff of smoke is you going rich from the misfire.

I also try not to "nail" the throttle. If you've gotta nail it, you've gotta nail it, but I try not to make it a habit. I ease into it to let the fuel catch up to the fucking pint sized turbo we have. I'm not talking about driving like granny, but giving it a potato or two going from cruise to WOT rather than putting your foot through the firewall may help you avoid some KR, especially below 3,000 RPM.

[Lex]

I wouldn't worry about low load KR.

Only KR I would worry about is WOT.

[Fobio]

Originally Posted by Lex I wouldn't worry about low load KR. Only KR I would worry about is WOT.

That's basically the assumption I've taken since getting a SRI and monitoring thru the DH...once I confirmed I wasn't the only one, I never looked back.

[clos561]

ive always let off the gas when im cruising at 70+ and see high kr of 5 or so. next time ill let it ride. my whole ride up to the SU meet i was getting kr but i would let off the gas when ever my warnings went off. so if tahts true then that explains why i got it almos the whole way up. the ecu couldnt learn and adjust because i was letting off the gas.

[Lex]

Originally Posted by clos561 ive always let off the gas when im cruising at 70+ and see high kr of 5 or so. next time ill let it ride. my whole ride up to the SU meet i was getting kr but i would let off the gas when ever my warnings went off. so if tahts true then that explains why i got it almos the whole way up. the ecu couldnt learn and adjust because i was letting off the gas.

At low loads the ECU rides the knock threshold to achieve maximum efficiency and relies on the knock sensor (KR) for this.

The fact that engines let go at light loads has nothing to do with KR at light loads. The damage is done during high loads and experiencing abnormal combustion.

[bast525]

yeah I did need to clarify... I am really no longer concerned about part throttle KR. I have 19,000 miles on my current plugs... guess it would not hurt to change them. I've had misfires from spark cut before on other cars (bad plug wires usually in those cases) and it was not as violent as this, but I won't argue that it is a possibility.

The thing that strikes me is how RARE and RANDOM it is. There is no pattern, it can seemingly happen at any time, it tends to happen usually in low gear... 1st or 2nd, right as boost builds.

People have said it's my fuel pump but the times I've ever happened to catch a log of this, fuel pressure was fine...

[Haltech]

case closed, fookers... lol

[ungrave]

Lex,
What about audible part throttle knock? I'm not talking about KR. Actual knock itself. I've heard the worst knock in my life at 10-20% throttle when going from vacuum to just starting to boost when accelerating up an on-ramp. Sounded like mini-firecrackers. Could this be bending rods or causing other damage that would cause the engine to let go later? My understanding is that any audible knock is really bad for an engine whether it's part throttle or full throttle.

Originally Posted by Lex At low loads the ECU rides the knock threshold to achieve maximum efficiency and relies on the knock sensor (KR) for this. The fact that engines let go at light loads has nothing to do with KR at light loads. The damage is done during high loads and experiencing abnormal combustion.

[SpeedSixxx]

Originally Posted by bast525 That's it? that's the guaranteed recipe for no more knock or no blown engine? What about meth? What about removing the balance shaft? Who's having the most success with tuning themselves using ATR? Not being sarcastic... these are all things I've read that someone or other has suggested COULD be causing the problem. I just got done reading through SLS MS3's blown engine thread... I want to think that because I am so lightly modded (intake and AP) that I am safe, but when I am leaving a light or whatever and get on it in 1st/2nd/3rd gear, and the car bucks and I hear sounds no engine should make, and a big puff of smoke out the back... I don't think I'm safe either way.

so you're saying that you actually stutter and shit and hear noise?...now I know my car is safe and good..LOL

i never once stuttered or any of that u talk about. and I never hear any knock unless i suck at taking off from a light in first and i almost stall (almost never) ..only when i shut the car off does it sound like a 1920's car knocking...but i think thats all speed motors...

[stevessvt]

Was on a 20 mile drive today. Was in 6th about 75 mph and went wot to pass someone and the dashhawk flashed a knock event, but I didn't see it in time to see what kind of knock it was. I deffinately felt a pause in acceleration. Should I worry? Completely stock except for second cat delete.

[SpeedSixxx]

Originally Posted by stevessvt Was on a 20 mile drive today. Was in 6th about 75 mph and went wot to pass someone and the dashhawk flashed a knock event, but I didn't see it in time to see what kind of knock it was. I deffinately felt a pause in acceleration. Should I worry? Completely stock except for second cat delete.

dont worry about it at all..just ignore...

do urself a favor and continue to hit the gas while the knock warning goes off...ur car will learn and this wont happen as often

[stevessvt]

On way home I nailed it a few times and no knock this time out. I guess it learned it's lesson.

[evidence]

Originally Posted by stevessvt On way home I nailed it a few times and no knock this time out. I guess it learned it's lesson.

Hmm.. well there is still the theory that you collected/pooled some fluids in the intake/PCV system while cruising for so long, and went WOT and sucked it all up. Just something to keep in mind that hasn't been dis proven yet. The OCC will help with this.

Personally during long cruises I ease onto the throttle every now and then and hit a bit of boost to clean it out. If in the end it does hold merrit, you don't want this happening at WOT being sucked up very quickly and at full timing.

[stevessvt]

So was driving again, was only a few minutes on the road. At 60 I rolled in to it in 6th to pass someone. Heard a ping, felt the car slow a not and saw the DH flashing a 7.0 KR! WTF? I am bone stock except second cat delete! I am scared shitless I'm going to be driving somewhere and it's going to puke it's guts out.

Coincidence? I Just realized I put $20 in gas on Sunday just before the first knock event.

[Blackspeed]

Originally Posted by SpeedSixxx when i shut the car off does it sound like a 1920's car knocking.

i hate that sound.
this quote belongs in the thread" you know you have a speed 3 when..."

[jahman]

This is pretty much what I thought also. I've also learned to ignore the KR when entering the next gear. Seems to be the same thing as part throttle cruise KR. It learned and now it doesnt do it much at all.

ALso whats interesting is that on my morning commute to work, I can predict EXACTLY when KR is going to happen. It happens in the same spot every day all the time. It hits about 4.6 and does the count down. So it seems to have some kind of "schedule" to it probably related to distance and not time, as I've gone in various traffic conditions, got behind someone really slow, or drove really fast and it still happens at the same spot.

[stevessvt]

So am I being a drama queen? Should I not over think it?

[tunersteve]

Originally Posted by smakdown61 I drive 120 miles a day roundtrip for work and I just ignore the cruise knock. Its just the ecu trying hard squeeze out as much timing as it can for good gas mileage. How did I confirm this? Here are some observations: 1. The knock doesn't just show up then disappear. It will throw 4 or 5 degrees (supposedly) and slowly work its way down to zero like its testing itself. 4 or 5 degrees of retard when ur running 40+ isn't shit and you won't feel it. 2. Instead of lifting when I see KR I started to just let it ride. After a few times of rolling down to zero, it actually stopped KR'ing at cruise. When you lift, it doesn't give the ecu a chance to learn so it keeps trying. 3. According to the mazda DISI training doc, the ecu can only pull up to 6 degrees of timing during an actual detonation situation. I've seen 6+ kr during 80mph cruise quite a few times without the car stumbling or hesitating.

Smak, you and I think alike. I had actually made this same statement a while ago as well, with the same exact scenarios and results:

My PT Knock 'Experiment' - Mazda Forums

Glad to see that we're on to something.

Honestly, local guys who don't monitor KR don't seem to have a problem. I actually am going to raise my warnings on the DH above 6 for the low end of the alerts, since anything above that should be legit (and bad).

[Speedee3]

I have to agree with Nytmar. I think too much info can be a bad thing. Knock and pinging can be heard pretty readily when it occurs. These ecu tuned cars (i miss the old school "tuning") are tweaked for ragged edge mileage etc, so that thresholds are often being crossed that while visible on a Dashawk, are negligable...in "most" cases. (and on cars with stock components/tunes)

Sometimes, ignorance is bliss.

My 2001 Rodeo has pinged under "float" conditions...(steady speed, barely on the throttle) since mile 1. Damn thing wants premium fuel, sooooo thats what it gets. The tune is an example of a manufacturer cutting parameters tooooooo close.

Ken

[2007speed3]

Today i was in 5th at around 3100 3200 rpms, kr shot to 5.9 and held it for about 1 mile, it did not change at all. I hit a bump in the road and it went away, my throttle position and rpms did not change tho, so wtf....

[slo4now]

Originally Posted by smakdown61 Do you monitor with a dashhawk?

Better late than never, but yes i monitor with a dashhawk.

[Erich]

Been trying this this last couple of days, and sure enough my PT knock has been slowly disappearing. Down to about a quarter of what it was 3 days ago.

[stevessvt]

Curious,...if a rod was tweaked, would you pull less vacuum at idle?

Originally Posted by Speedee3 I have to agree with Nytmar. I think too much info can be a bad thing. Knock and pinging can be heard pretty readily when it occurs. These ecu tuned cars (i miss the old school "tuning") are tweaked for ragged edge mileage etc, so that thresholds are often being crossed that while visible on a Dashawk, are negligable...in "most" cases. (and on cars with stock components/tunes) Sometimes, ignorance is bliss. My 2001 Rodeo has pinged under "float" conditions...(steady speed, barely on the throttle) since mile 1. Damn thing wants premium fuel, sooooo thats what it gets. The tune is an example of a manufacturer cutting parameters tooooooo close. Ken

What are your thoughts on knock events you can hear?