Engine rebuilt - noise and KR

[mrQQ]

Hi,

so I had my engine rebuild. I'm not sure if because of BSD, or something else, but I have a lot of vibrations and noisy engine bay now. Does everyone have so?

Also, related to that, or not related, I dont know, but now I have a lot of KR registered at high gear low rpm throttle input. As in sometimes every blip on accelerator would produce 2-5 KR. I can't for my life find anything loose under the bonnet.

So my questions are, to those who rebuilt their engines - did you have something like that? If so, what did you do? Could I just raise the KR min RPM value to say 2.5k?

[mzr0818]

Curious to see on this. Noise and vibration is normal with a balance shaft delete, but I have not heard of acquiring KR with it as well

[Tokay444]

Bring it back to whomever built it and get them to do it right.

[Nitr0EngiE]

I feel bad for you as it seems your alone and exiled where you live with no valid support but to answer your question no something is really wrong you should not get KR like that. sounds like something serious like maybe a loose rod cap or something you dont want to me loose is loose

[Justin@Freektune]

That is quite normal in a lot of engines. usually around 3k and .3-.5 load.

[mrQQ]

Originally Posted by Justin@Freektune That is quite normal in a lot of engines. usually around 3k and .3-.5 load.

well you mister are damn right. I had a constant KR light for all my 50 mile trip @ 80mph @ 3.2k rpm @ 0.5 load. It was fluctuating 1-6 but it was constantly on. Damn that's annoying.

Should i just increase min load to 0.6?

edit: on the same note - has anyone ever had knock sensor go bad? the part is 75$ which i don't want to shell out just for a guess. But I really hate the car as it is now, I simply don't trust it.

[btstarcher]

Originally Posted by mrQQ well you mister are damn right. I had a constant KR light for all my 50 mile trip @ 80mph @ 3.2k rpm @ 0.5 load. It was fluctuating 1-6 but it was constantly on. Damn that's annoying. Should i just increase min load to 0.6? edit: on the same note - has anyone ever had knock sensor go bad? the part is 75$ which i don't want to shell out just for a guess. But I really hate the car as it is now, I simply don't trust it.

Yes, knock sensors go bad sometimes. I thought you already replaced it though?

[Justin@Freektune]

Originally Posted by mrQQ well you mister are damn right. I had a constant KR light for all my 50 mile trip @ 80mph @ 3.2k rpm @ 0.5 load. It was fluctuating 1-6 but it was constantly on. Damn that's annoying. Should i just increase min load to 0.6? edit: on the same note - has anyone ever had knock sensor go bad? the part is 75$ which i don't want to shell out just for a guess. But I really hate the car as it is now, I simply don't trust it.

I would honestly just turn the min load on the sensor at that rpm to .9 or so.

[mrQQ]

When you say normal..

I have this at around 2k. At loads of 0.5-0.7. That is driving in 5th gear at 35mph and lightly pressing on accelerator. I almost constantly get KR raning anywhere from 0.3 to 8. After some driving though, it usually disappears mostly.

Is this the same that you noticed, Justin?

and Tokay, I know I could do that, but let's be fair - they shop will be clueless if I don't give any hints. So I'd rather collect some info before bringing it to them. I've chedked everything I can reach from top of engine bay, and I just don't see anything loose.

Worst case scenario it's something inside. But how to verify?

edit: could it be cause of the injector seals? But I guess that would be high load knock... this is only very very low rpm and load..

btw, IF it would be something in the engine, wouldn't it happen also in higher rpm/load? I don't think I even saw a single instance of KR above 2.5k!

[Dizzy Turbo]

I though part throttle kr was normal lol

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[Nitr0EngiE]

he sounded like he was describing something more severe than the normal PT KR we see

8.0 KR ?

[Justin@Freektune]

Yes some cars will max out the knock sensor in that region. If you log it, I can almost guarantee its between .3-.5 load at 3k rpms. Has a lot to do of the harmonic frequencies

[phate]

Sounds normal to me. Is the engine high compression? I get some very real knock that I can hear running 93 octane with some wicked counts of KR. It goes silent when running E85. You can test by running some high octane fuel through it.

[Jeff23spl]

what is the engine build list ? CR ? and work done ?

It may be normal to get more kr but it may be an issue also...
Have you checked VVT for proper installation and chain resistance ?
Did you kept the OEM dual mass FW ? i just went from 5-6deg of KR while cruizing on stock bloc to 0.5 just by replacing a worn tranny bearing and a very very loose dual FW by a solid one.

Then it all goes with remanufacturing work, balancing etc.

something loose like a bearing cap or a too large gap on it would hardly drop the oil pressure...It could be something to check and feel confident on the work if the pressure is good.

But we have large dispacement cylinder with a long stroke so harmonic noise is there for sure and i can't tell how much is normal and how much is too much lol

[mrQQ]

10.6:1 pistons, engine build done

fidanza flywheel. VVT and chain are new. Installation is proper, I have absolutely no issues driving or idling. Whats a bearing cap? I'm guessing theres no checking that without pulling the engine out. If so, then I need more evidence to present to the shop than just "i get KR on my dashhawk"...

the KR happens at 2k. At 2.5k its completely gone.

I just did a test drive. After around 5 miles or so, it goes away completely aswell. And doesnt happen anymore.

I will try the high octane fuel. phate - I can't hear anything when it happens.. what rpm does yours happen at? Would 2k rpm, 0.7 load really be enough to have knocking on 93 on stock tune?

[phate]

Originally Posted by mrQQ I just did a test drive. After around 5 miles or so, it goes away completely aswell. And doesnt happen anymore. I will try the high octane fuel. phate - I can't hear anything when it happens.. what rpm does yours happen at? Would 2k rpm, 0.7 load really be enough to have knocking on 93 on stock tune?

If it only happens when cold, definitely don't worry about it, lol. Things take time to fully warm and expand, and we already have pretty noisy engines.

Mine happens pretty much everywhere when running 93 in warm weather. I expected it, so nbd. I run E85 99% of the time.

[john.e.stoner]

Originally Posted by mrQQ 10.6:1 pistons, engine build done fidanza flywheel. VVT and chain are new. Installation is proper, I have absolutely no issues driving or idling. Whats a bearing cap? I'm guessing theres no checking that without pulling the engine out. If so, then I need more evidence to present to the shop than just "i get KR on my dashhawk"... the KR happens at 2k. At 2.5k its completely gone. I just did a test drive. After around 5 miles or so, it goes away completely aswell. And doesnt happen anymore. I will try the high octane fuel. phate - I can't hear anything when it happens.. what rpm does yours happen at? Would 2k rpm, 0.7 load really be enough to have knocking on 93 on stock tune?

I just got a built engine and running the BNRS3 and I also see some Knock on my AP, and it's been up to 8, but then it goes away within 5 minutes of normal driving and then nothing. I see almost zero KR on my initial logs. My engine vibrates like mad, I have all the MMs now and I get all kinds of crazy harmonics (noise) at various RPMs, so like 50mph in 5th gear, rattles bad, 70 mph in 6th gear, rattles bad. I'm not sure if I'm seeing KR due to engine rattle/noise, but it is only when it's cold and for like 5 minutes, then the KR seems to be gone.

Speed Perf6rmanc3 MZR Built Long block
- Wiseco OTS Pistons
- Manley H-Beam Rods
- ARP 2000 Rod Bolts
- Speed Perf6rmanc3 10mm H-11 Head Studs
- Clevite Main & Rod Bearings

[TiGraySpeed6]

Once you're sure that there's no exciting problem at play you could raise the min load threshold some- 0.90 would mask that static pretty well

[mrQQ]

Well yeah, I already thought through the "just hide it" part of it. I need to be sure it's not a real knock and not some other issue at play, so that I don't shoot myself in the foot. I guess I need to give it some more time, see if it persists, then put in some E juicy and see how that works out.

[Jeff23spl]

at cold, it is definitely worse but usually KR shouldn't show up before 160 deg F of coolant.

Usually at warm up, the pcm do a 60 deg timing test also, it could be seen on your logs. With the timing angry pcm and 10.6:1 pistons it may naturally do that but as long it disapear when it is warmed, i wouldn't worry much about it.


The bearing cap is the removeable parts that hold cranks bearing. Their is one on each rod that bolt up to the rod to hold itself around the crankshaft. Maybe you name it differently but it is where the rod bearing sit. So when this part get loose, you may hear a ''tang'' tang'' tang'' few seconds and usually a last and louder ''TAAAAANNNNG'' then all you oil spill the ground and you need a new engine ....
So i don't think it is your problem and if it was, you would hear it very easily.

[mrQQ]

so I thought that KR only appears once the car passes ECT threshold for KR. Turns out it not like that.

KR doesnt appear till car is fully warmed up. Then it appears. And the goes away after around 10 miles of driving. Huh.

[Jeff23spl]

Is the timing advance different when kr appear and when you get again to theses conditions after warm up and kr is gone ? You can check all parameters to see if something change on the electronic but it is probably more mecanical related...

On my winter observations with dual mass fw (Not build yet and no bsd) it was looking like if the pcm was willing to see KR by rising timing up to 60deg once, right after coolant warmed up. Even if my ATR table limit it to 55deg. I explained to myself that it may be a way to check fuel octance each morning but...strange.... Just because it get worse with colder temp, i think now, that it may just be mecanically related and appear each morning before the oil get warmed up completly. I just didn't figured out how timing could rise to 60 when limited to 55, their should be a calcul or a table that bypass this limit.

for the pcm, when coolant reach 160f it is warmed but it takes longer for the oil and all parts to get to their opperating temp. Especially in cold weather...

[phate]

Oil takes quite a bit longer to warm up than coolant.

[mrQQ]

So you have pretty much the same engine as me.

So today i had around half of fuel left, around 30l, and added 10l of E85.

That did nothing. Ok, the KR number might be lower, but I'm not even sure about that. Still happening same time. Also, when cruising, I used to get some KR which would settle, as ECU plays with timing. Now I get almost constant KR reading within periods. Fuck that.

But I have one more symptom. Light accelerator from low rpm sometimes stutters. It doesn't match KR - when stutter happens no KR, when KR happens no stutter. But now I'm thinking - could it be my spark plugs? I switch back to stock before engine build, trying to troubleshoot my trims, and the stockers have seen some life. But they used to work fine on old engine, nothing like this. Could the higher compression have been enough to make old spark plugs not good enough?

More importantly, could spark plugs cause such KR readings?

[JgamB]

Doesn't this sound like piston slap commonly associated with built motors and looser tolerances?

[Tokay444]

Injector seals.

Do a leak test.

[mrQQ]

How do I do a leak test for injector seals? Shouldn't they leak only in high load?

edit: now randomly happens even in first gear.

edit 2: so I swapped in my lightly used set of ITV22's which didn't change anything.

[Realgib3]

This all sounds normal to me.

[mrQQ]

The fact that I cruise with my KR flashing 50% of the time doesn't sound normal to me...

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[Jeff23spl]

Originally Posted by mrQQ The fact that I cruise with my KR flashing 50% of the time doesn't sound normal to me... Sent from my GT-I9505 using Tapatalk

have you made any check ?
-What is your oil pressure hot and cold ? (Need a gauge)
-Is your VVT chain tight in TDC (Don't presume it is fine but check it)
-Did you made an oil change since rebuild ? If not make one and check carreffuly the oil.
Did you check compression/leak down ?

Normal knock noise of a rebuilt engine with more space between parts to support more heat is normal and this will show normal results from the above tests.
Removed BS will, for sure, create more noise.

If it was really bad: Bad knock noise comes from something bad inside the engine. Too much play around bearing wouldn't old oil pressure and if it touch metal on metal, you would see metal in your oil. This problem wouldn't go away when the engine is warmed up like yours do. IT is the same for any other mecanical issue with piston/rings etc

[Realgib3]

Ok

[mrQQ]

Hi,

i'm still in break-in, so I will do the checks after that.

So I've tried reducing ignition advance just for the kicks, and it did nothing.

Next I set KR min rpm to 2200 and didn't see a single instance of KR afterwards.

[jm211]

I agree with many above posts. Forged requires more tolerance of moving parts which means more noise from engine. Much worse when cold until things expand.

The major point to support this is it seems as if you have no kr when warm and in high rpm, only when cold and e85 didnt help, so it is not the tune. So it is mechanical.

Much of this is normal for a built motor.

I would still perform the leakdown for injector seals and make sure everything is clean (boost leaks, etc.)

Once you know you are 100% you can increase kr decay rate or turn off in lower rpm/load region to avoid the ecu fucking with your timing.

[mrQQ]

Yeah, I'm not sure how turning of knock sensor would work with ECU methodology of increasing timing till it detects KR.

edit: also, I wonder why I still have some small stutter in low rpm acceleration. Seems to be more pronounced after fresh flash, so could be before ecu learns of the trims. But since my trims are within 3%, I wonder why can I feel it.

By the way: when reinstalling my downpipe (ebay one), we noticed that thread in original wideband location is messed up. So we moved it to the spare bung which is mean for EGT or whatever. Could this be throwing something off? I get normal AFR readings in DH. In the image, from the left first bung is where it originally was, second is where we moved it.

[btstarcher]

It's obviously just noise. It's intermittent, and it doesn't go away with higher octane.

[taf0422]

This completely sounds normal to be as well. See how she does once the break in is over.

On a side note my built motor doesn't knock at all. In any situation. On the stock motor used to have KR constantly on the highway as it kept changing the timing. In the built motor it doesn't even do that. I havent even had knock during any pulls. Lol. 23k miles into

[btstarcher]

Originally Posted by taf0422 This completely sounds normal to be as well. See how she does once the break in is over. On a side note my built motor doesn't knock at all. In any situation. On the stock motor used to have KR constantly on the highway as it kept changing the timing. In the built motor it doesn't even do that. I havent even had knock during any pulls. Lol. 23k miles into

I'd check out your knock sensor just to be safe; it's not normal to have 0 KR.

[taf0422]

Originally Posted by btstarcher I'd check out your knock sensor just to be safe; it's not normal to have 0 KR.

Already did that about 12k miles ago and still same result. Its been that way since day one and Justin has tuned it. I regularly send him logs just to make sure. Compression is still spot on and it just got back from a 1200 mile road trip with no issue.

[btstarcher]

Originally Posted by taf0422 Already did that about 12k miles ago and still same result. Its been that way since day one and Justin has tuned it. I regularly send him logs just to make sure. Compression is still spot on and it just got back from a 1200 mile road trip with no issue.

What type of fuel are you using?

[taf0422]

Originally Posted by btstarcher What type of fuel are you using?

93 shell with 3 gallons e85 shell

My other map is extremely dulled down. Minimal timing and less boost. 93 only on this one. All have meth as well.