Spark Knock noise?

Jordo! · 02-25-2014, 04:06 PM

I was gonna say, that rattle sounds like something in the exhaust, so could be loose heatshield.

Random misses are frequently caused by intermittent vacuum leaks -- which may also cause the car to stall or the RPM's to drop as it attempts to get within the programmed idle range.

I'd check for a vacuum leak -- anything near the primary O2 could be the cause (including where the headers meet the cats), and definitely double check everything along the intake tract.

Good luck!

EDIT: wait, so you had bad coilpacks? Hmm.

Not sure about the other noise -- doesn't sound like valve tap to me. Any other symptoms?

TedB370z · 02-25-2014, 04:16 PM

It hesitates when it happens, but other that that, gas mileage is good, cruising there's no noise or issues...

Jordo! · 02-25-2014, 04:21 PM

I'd still search for vacuum leaks -- if more air gets sucked in than is measured, it will run lean and attempt to correct with fuel trims; that could cause the running rough and hesitation issues.

TedB370z · 03-04-2014, 01:58 PM

Update:

I pressure tested the intakes/plenum and found a leak, it was the passenger side breather that goes to the valve cover (I have K&N Typhoon Intakes) Needed some thread seal tape. Also looked at other K&N installs, and the previous owner left on the baffles/sound dampeners, which after reading the installation instructions I downloaded, K&N says to remove, so those are gone, ordered the z1 motorsports replacements.

Changed the oil with Mobil 1 Synthetic 5w30 (I was using conventional 5w30 the last 2 oil changes since I got the Z) and the violent valve/chain/whatever noise now rarely happens, as does the slight hesitation related to it. I'm wondering if the hydraulic chain tensioner was stuck from the thicker oil, causing the chain to slack and the timing go goofy?

I still have the odd issue of when I'm accelerating at a normal pace (not WOT) it'll just drop RPMs like before, but not as drastic as before I fixed the intake leak, only 200 - 300RPM.

TedB370z · 03-07-2014, 09:43 PM

Spoke too soon...

It's still making that awful noise, only when in gear, only when from a stop, only when I slowly accelerate, and it still hesitates when it happens. Give it more gas, and it catches up with itself. But, still, intermittently.

I re-pressure tested the intakes after I installed the Z1 Motorsports breather tubes, and there are no leaks, also got under the car, and except for a small leak at the passenger side muffler (that I was able to tighten and fix) there are no leaks at any of the other flanges, no leaks at the 02 sensors, and no CEL or codes. Even when the issue occurs, there's no CEL or other warning light.

Gas mileage is good, power at WOT is good, and no other weird noises.

I'm at a loss on this.

Joepro · 03-07-2014, 09:49 PM

Did you check the mafs? We had a,civic run like crap, because it caught a small bug on the sensor, probably not it but worth a shot.

TedB370z · 03-07-2014, 09:57 PM

YYYep, I used that CRC mass airflow sensor cleaner, also did the idle air learning procedure just in case.

Joepro · 03-07-2014, 10:03 PM

Seafoam? Id do a, can in the gas and intake..cant hurt at this point

TedB370z · 03-07-2014, 10:11 PM

Did that too lol, I actually just ran that tank that I put the Seafoam in down to E and filled up at BP

TedB370z · 03-07-2014, 10:16 PM

I'll try it through the intake tomorrow - you mean the brake booster vacuum tube?

Joepro · 03-07-2014, 10:22 PM

Ya that will clean out manifold and lower collector again cant hurt, but this one seems beyond my diagnostic skills at this point im just guessing at this point to be honest

TedB370z · 03-07-2014, 10:40 PM

Yeah I'm completely lost.

N0SL3N · 03-08-2014, 07:46 AM

Just a shot in the dark here but try checking the transmission mount. I say this because I had very similar symptoms in my sisters jeep. It rattled in gear and during acceleration but not when cruising. Luckily it is pretty easy to take off and inspect... or just upgrade to the Z1 unit while you are at it.

SouthArk370Z · 03-08-2014, 07:58 AM

It might help to do some parameter monitoring and/or logging.

You can find cheap ($20-40) ODB/CAN-to-USB convertors on the Intertubes and there are several free programs available. I have a page that lists/reviews some of the programs at the link in my sig.

If you have an Android device, there is an app called Torque available.

If you need to dig deeper than what the above can handle, one of the tuning apps would be an option.

TedB370z · 03-08-2014, 10:14 AM

I actually have one, I'll post some data logs soon...

02-25-2014, 04:06 PM	#1 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 418	I was gonna say, that rattle sounds like something in the exhaust, so could be loose heatshield. Random misses are frequently caused by intermittent vacuum leaks -- which may also cause the car to stall or the RPM's to drop as it attempts to get within the programmed idle range. I'd check for a vacuum leak -- anything near the primary O2 could be the cause (including where the headers meet the cats), and definitely double check everything along the intake tract. Good luck! EDIT: wait, so you had bad coilpacks? Hmm. Not sure about the other noise -- doesn't sound like valve tap to me. Any other symptoms? __________________ Enjoy it. Destroy it. Last edited by Jordo!; 02-25-2014 at 04:09 PM.

02-25-2014, 04:21 PM	#3 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 418	I'd still search for vacuum leaks -- if more air gets sucked in than is measured, it will run lean and attempt to correct with fuel trims; that could cause the running rough and hesitation issues. __________________ Enjoy it. Destroy it.

03-07-2014, 09:49 PM	#6 (permalink)
Joepro A True Z Fanatic Join Date: Aug 2012 Location: Athens ohio Posts: 1,213 Drives: Company car Rep Power: 34	Did you check the mafs? We had a,civic run like crap, because it caught a small bug on the sensor, probably not it but worth a shot. __________________ Swift\|Koni\|SPC\| FI CBE\|Z1\|Stillen\|Sbend\|Zspeed\|R/T Tuned\|523 whp\|458 tq\|10.5 psi\|SOLD Joepro's Journal\|Joepro's Boosted Performance Build \|Pittsburgh-Western-Pa-Ohio-Wv-Group

03-07-2014, 10:03 PM	#8 (permalink)
Joepro A True Z Fanatic Join Date: Aug 2012 Location: Athens ohio Posts: 1,213 Drives: Company car Rep Power: 34	Seafoam? Id do a, can in the gas and intake..cant hurt at this point __________________ Swift\|Koni\|SPC\| FI CBE\|Z1\|Stillen\|Sbend\|Zspeed\|R/T Tuned\|523 whp\|458 tq\|10.5 psi\|SOLD Joepro's Journal\|Joepro's Boosted Performance Build \|Pittsburgh-Western-Pa-Ohio-Wv-Group

03-07-2014, 10:22 PM	#11 (permalink)
Joepro A True Z Fanatic Join Date: Aug 2012 Location: Athens ohio Posts: 1,213 Drives: Company car Rep Power: 34	Ya that will clean out manifold and lower collector again cant hurt, but this one seems beyond my diagnostic skills at this point im just guessing at this point to be honest __________________ Swift\|Koni\|SPC\| FI CBE\|Z1\|Stillen\|Sbend\|Zspeed\|R/T Tuned\|523 whp\|458 tq\|10.5 psi\|SOLD Joepro's Journal\|Joepro's Boosted Performance Build \|Pittsburgh-Western-Pa-Ohio-Wv-Group

02-25-2014, 04:16 PM	#2 (permalink)
TedB370z Base Member Join Date: Aug 2013 Location: Pittsburgh, PA Posts: 87 Drives: 09 Nissan 370z Rep Power: 12	It hesitates when it happens, but other that that, gas mileage is good, cruising there's no noise or issues...

03-04-2014, 01:58 PM	#4 (permalink)
TedB370z Base Member Join Date: Aug 2013 Location: Pittsburgh, PA Posts: 87 Drives: 09 Nissan 370z Rep Power: 12	Update: I pressure tested the intakes/plenum and found a leak, it was the passenger side breather that goes to the valve cover (I have K&N Typhoon Intakes) Needed some thread seal tape. Also looked at other K&N installs, and the previous owner left on the baffles/sound dampeners, which after reading the installation instructions I downloaded, K&N says to remove, so those are gone, ordered the z1 motorsports replacements. Changed the oil with Mobil 1 Synthetic 5w30 (I was using conventional 5w30 the last 2 oil changes since I got the Z) and the violent valve/chain/whatever noise now rarely happens, as does the slight hesitation related to it. I'm wondering if the hydraulic chain tensioner was stuck from the thicker oil, causing the chain to slack and the timing go goofy? I still have the odd issue of when I'm accelerating at a normal pace (not WOT) it'll just drop RPMs like before, but not as drastic as before I fixed the intake leak, only 200 - 300RPM.

03-07-2014, 09:43 PM	#5 (permalink)
TedB370z Base Member Join Date: Aug 2013 Location: Pittsburgh, PA Posts: 87 Drives: 09 Nissan 370z Rep Power: 12	Spoke too soon... It's still making that awful noise, only when in gear, only when from a stop, only when I slowly accelerate, and it still hesitates when it happens. Give it more gas, and it catches up with itself. But, still, intermittently. I re-pressure tested the intakes after I installed the Z1 Motorsports breather tubes, and there are no leaks, also got under the car, and except for a small leak at the passenger side muffler (that I was able to tighten and fix) there are no leaks at any of the other flanges, no leaks at the 02 sensors, and no CEL or codes. Even when the issue occurs, there's no CEL or other warning light. Gas mileage is good, power at WOT is good, and no other weird noises. I'm at a loss on this.

03-07-2014, 09:57 PM	#7 (permalink)
TedB370z Base Member Join Date: Aug 2013 Location: Pittsburgh, PA Posts: 87 Drives: 09 Nissan 370z Rep Power: 12	YYYep, I used that CRC mass airflow sensor cleaner, also did the idle air learning procedure just in case.

03-07-2014, 10:11 PM	#9 (permalink)
TedB370z Base Member Join Date: Aug 2013 Location: Pittsburgh, PA Posts: 87 Drives: 09 Nissan 370z Rep Power: 12	Did that too lol, I actually just ran that tank that I put the Seafoam in down to E and filled up at BP

03-07-2014, 10:16 PM	#10 (permalink)
TedB370z Base Member Join Date: Aug 2013 Location: Pittsburgh, PA Posts: 87 Drives: 09 Nissan 370z Rep Power: 12	I'll try it through the intake tomorrow - you mean the brake booster vacuum tube?

03-07-2014, 10:40 PM	#12 (permalink)
TedB370z Base Member Join Date: Aug 2013 Location: Pittsburgh, PA Posts: 87 Drives: 09 Nissan 370z Rep Power: 12	Yeah I'm completely lost.

03-08-2014, 07:46 AM	#13 (permalink)
N0SL3N Enthusiast Member Join Date: Nov 2011 Location: Toronto Posts: 376 Drives: 2009 PG 370z 6MT Rep Power: 35	Just a shot in the dark here but try checking the transmission mount. I say this because I had very similar symptoms in my sisters jeep. It rattled in gear and during acceleration but not when cruising. Luckily it is pretty easy to take off and inspect... or just upgrade to the Z1 unit while you are at it. __________________ \| Akuma \| Motordyne \| Z1 \| NST \| CNT \| Stillen \| Avant Garde \| RJM \| Performix \| Tint \| LED \| GTR \| Nissan \|

03-08-2014, 07:58 AM	#14 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324198	It might help to do some parameter monitoring and/or logging. You can find cheap ($20-40) ODB/CAN-to-USB convertors on the Intertubes and there are several free programs available. I have a page that lists/reviews some of the programs at the link in my sig. If you have an Android device, there is an app called Torque available. If you need to dig deeper than what the above can handle, one of the tuning apps would be an option. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

03-08-2014, 10:14 AM	#15 (permalink)
TedB370z Base Member Join Date: Aug 2013 Location: Pittsburgh, PA Posts: 87 Drives: 09 Nissan 370z Rep Power: 12	I actually have one, I'll post some data logs soon... SouthArk370Z likes this.

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