Clicking Noise Heard Upon Throttle Stab - ZR-1 Net Registry Forums

KJL · 08-30-2014

Hearing a little clicking noise when a mildly stab the throttle from idle. Got my stethoscope out but seem most noticeable if I removed the rod part and just listened in the general exhaust area. Couldn't pick up much when placing the rod against the IH's or head. I guues it could be an exhaust leak but it sounds to metallic for that. Engine runs fine. I did just complete some port work on the heads and it is possible a few small flecks of aluminum may have made it into the cylinder. Not that familiar with OHC engines and looking for some input regarding possible cause and additional diagnostic ideas.

I can also hear a little click when driving with the windows open at times.

Just dyno'd the engine to 7000 rpm and it achieved 400 rwhp. Clicking was there before testing however.

Thanks!

Marc Haibeck · 08-31-2014

It's likely that the dual mass flywheel is a little loose. It's just an annoying sound. It might get louder but does not lead to a catastrophic failure. You can address it when the next clutch service is due.

KJL · 09-02-2014

After further checking I am not sure if sound is coming from rear of engine. It is a light metallic tick that would be compatible to a noisy lifter. It only happens upon throttle stab at idle and also seems to happen while throttling under load. I wish there were a trained ear locally I could bring it to who knows these engines. I have also heard similar sounds form noisy cam chain followers on other OHC engines. Is there anything in the valve train that could be the cause if it isn't the fly wheel?

LGAFF · 09-02-2014

Mine has lifter noise also....brand new lifters too on the rebuild too....6K+ miles no issues. Comes and goes seems to be dependent on the weather....BMW had a lifter issue in their N52 engines....

Other possibilities: exhaust leak, chain tensioner(unlikely), Serp belt tensioner...

KJL · 09-02-2014

Thanks for the input. Just annoying and I don't want to ignore anything that may get worse.

LGAFF · 09-02-2014

this sound?

https://www.youtube.com/watch?v=EhLP-RkFGXM

KJL · 09-03-2014

I recorded the noise with my phone while holding it down near the driver side exhaust manifold while I stab the throttle. I captures pretty much what I am hearing. It is definitely coming from this area of the engine.

mike100 · 09-03-2014

Sounds like a hairline exhaust leak. You hear it better as soon as the engine gets a load on it. I had a cracked Corsa resonator do that. tickety-ticked when you came off of coast and started going again. You could really hear it at low speeds when next to a wall or another vehicle.

KJL · 09-03-2014

Mike-

The recording was taken at the exhaust manifold area. I hope you are right. Probably should have turned the phone around but the sound is quite clear.

mike100 · 09-03-2014

Oh!- that's and exhaust leak for sure. Not sure if gasket or actual crack in pipe somewhere, but the absolute easiest way to find out in about 30 seconds is to get a decently long vacuum tube or small rubber hose as a probe. stick one end in your ear and use the other end to pass in close proximity to suspected leak areas and it will be obvious as hell and loud like a stethoscope. just blowing across the end of the tube makes a good test to show how well airflow is picked up by this test.

08-30-2014	#1
KJL Join Date: Mar 2013 Location: Roswell, GA Posts: 234	Clicking Noise Heard Upon Throttle Stab Hearing a little clicking noise when a mildly stab the throttle from idle. Got my stethoscope out but seem most noticeable if I removed the rod part and just listened in the general exhaust area. Couldn't pick up much when placing the rod against the IH's or head. I guues it could be an exhaust leak but it sounds to metallic for that. Engine runs fine. I did just complete some port work on the heads and it is possible a few small flecks of aluminum may have made it into the cylinder. Not that familiar with OHC engines and looking for some input regarding possible cause and additional diagnostic ideas. I can also hear a little click when driving with the windows open at times. Just dyno'd the engine to 7000 rpm and it achieved 400 rwhp. Clicking was there before testing however. Thanks! __________________ 1995 ZR1 #159 Ported,Corsa,4.10 Rear, Dual Disc RAM Clutch, Alum Flywheel, Haibeck Chip, ZFDoc Plates, Relocated Battery 400 rwhp 1992 ZR1 #280 Ported, Locked Secondary's, Flowmaster Exhaust, Haibeck Chip, 375rwhp 1996 Collectors LT4 (Stock) 1972 Convertible 434 Small Block 572 rwhp

08-31-2014	#2
Marc Haibeck Join Date: May 2007 Location: Addison IL Posts: 250	Re: Clicking Noise Heard Upon Throttle Stab It's likely that the dual mass flywheel is a little loose. It's just an annoying sound. It might get louder but does not lead to a catastrophic failure. You can address it when the next clutch service is due.

09-02-2014	#3
KJL Join Date: Mar 2013 Location: Roswell, GA Posts: 234	Re: Clicking Noise Heard Upon Throttle Stab After further checking I am not sure if sound is coming from rear of engine. It is a light metallic tick that would be compatible to a noisy lifter. It only happens upon throttle stab at idle and also seems to happen while throttling under load. I wish there were a trained ear locally I could bring it to who knows these engines. I have also heard similar sounds form noisy cam chain followers on other OHC engines. Is there anything in the valve train that could be the cause if it isn't the fly wheel? __________________ 1995 ZR1 #159 Ported,Corsa,4.10 Rear, Dual Disc RAM Clutch, Alum Flywheel, Haibeck Chip, ZFDoc Plates, Relocated Battery 400 rwhp 1992 ZR1 #280 Ported, Locked Secondary's, Flowmaster Exhaust, Haibeck Chip, 375rwhp 1996 Collectors LT4 (Stock) 1972 Convertible 434 Small Block 572 rwhp

09-02-2014	#4
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Clicking Noise Heard Upon Throttle Stab Mine has lifter noise also....brand new lifters too on the rebuild too....6K+ miles no issues. Comes and goes seems to be dependent on the weather....BMW had a lifter issue in their N52 engines.... Other possibilities: exhaust leak, chain tensioner(unlikely), Serp belt tensioner... __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

09-02-2014	#5
KJL Join Date: Mar 2013 Location: Roswell, GA Posts: 234	Re: Clicking Noise Heard Upon Throttle Stab Thanks for the input. Just annoying and I don't want to ignore anything that may get worse. __________________ 1995 ZR1 #159 Ported,Corsa,4.10 Rear, Dual Disc RAM Clutch, Alum Flywheel, Haibeck Chip, ZFDoc Plates, Relocated Battery 400 rwhp 1992 ZR1 #280 Ported, Locked Secondary's, Flowmaster Exhaust, Haibeck Chip, 375rwhp 1996 Collectors LT4 (Stock) 1972 Convertible 434 Small Block 572 rwhp

09-03-2014	#7
KJL Join Date: Mar 2013 Location: Roswell, GA Posts: 234	Re: Clicking Noise Heard Upon Throttle Stab I recorded the noise with my phone while holding it down near the driver side exhaust manifold while I stab the throttle. I captures pretty much what I am hearing. It is definitely coming from this area of the engine. __________________ 1995 ZR1 #159 Ported,Corsa,4.10 Rear, Dual Disc RAM Clutch, Alum Flywheel, Haibeck Chip, ZFDoc Plates, Relocated Battery 400 rwhp 1992 ZR1 #280 Ported, Locked Secondary's, Flowmaster Exhaust, Haibeck Chip, 375rwhp 1996 Collectors LT4 (Stock) 1972 Convertible 434 Small Block 572 rwhp Last edited by KJL; 09-03-2014 at 05:22 PM.

09-03-2014	#8
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,786	Re: Clicking Noise Heard Upon Throttle Stab Sounds like a hairline exhaust leak. You hear it better as soon as the engine gets a load on it. I had a cracked Corsa resonator do that. tickety-ticked when you came off of coast and started going again. You could really hear it at low speeds when next to a wall or another vehicle.