Engine Ticking - ZR-1 Net Registry Forums

Dmod81 · 04-14-2015

All - need your help. My engine has developed a tick. I drove it on Sunday - embarrassingly I did hit the rev limiter. There were no issues when I parked it. Today, when I started the car, I heard the tick. Video is here: https://youtu.be/jiUyyVhvMvk

It does increase with engine rpm, although there gets to be a point where I can't hear it due to exhaust noise. The car does seem to shake a bit. Oil is good and oil pressure is good. I attached my timing light to all of the plug wires, and got only very intermittent flashing on cylinder #6. I plugged in my Tech one, and the R Int is 146 with the L Int at 132. BLM is at 133 for both. Also, the O2 voltages were jumping around a lot.

Is the ticking/knocking noise likely the flywheel, and the overall problem likely the coil?

Thanks for all of your help.

mike100 · 04-14-2015

put a metal tube (like an old brake line) on a stethoscope or to a rubber hose you can stick in one ear and run it along the exhaust flange and any welds that might be leaking on the exhaust system.

XfireZ51 · 04-15-2015

A little more information would be helpful like, what year car, miles, mods, what side is the tick on, etc.

Dmod81 · 04-15-2015

92, 56000 miles, headers w/ cats/3" exhaust/Haibeck chip. Coils and injectors were replaced (Accels) in about 08, about 7,000 miles ago. I can't hear it very well from the top of the car, but can hear it better from under. Seems louder on the drivers side, but that may just be the garage wall echoing.

I'll also use a stethoscope to see if there is an exhaust leak or if there is any discernable noise under the can cover today.

So is the no light from the timing light on the #6 cylinder not really a smoking gun then? It just seemed weird that it worked on all 7 of the other wires.

XfireZ51 · 04-15-2015

The motor shake would suggest a miss. Which would be consistent with a cylinder not firing as indicated by the timing light. I'd swap the plugs between 4 and 6 and see if that changes at all. Also compare the color of the plugs to see if they look similar. And see what u get using the stethoscope as mike suggested.

Dmod81 · 04-15-2015

OK, I'll do all of that after work. Thanks

Dmod81 · 04-15-2015

Here's a picture of the plugs, 6 on top, 4 on bottom. # 6 did smell slightly of fuel. I switched the plugs, still no fire on cylinder 6. Nothing discernable/ conclusive heard with stethoscope.

I'm trying to look at this as an opportunity to port the top end!

RussMcB · 04-15-2015

Quote:

Originally Posted by Dmod81

I'm trying to look at this as an opportunity to port the top end!

Not a bad idea but make sure you identify your current problem first! :-)

I might have missed this earlier - Do you see a spark arching if you hold the spark plug boot near a grounding plug? That will be a huge clue to point you in the right direction.

Dmod81 · 04-15-2015

No, I don't see anything. So possibly either wire or coil. I'm going to replace both, I already have a set of wires and a set of gaskets.

I figured as long as I'm taking off the plenum, I might as well port since I've been wanting to. I'm also thinking about blocking the coolant as well so it will be easier to pull the plenum again.

Z51JEFF · 04-16-2015

Keep in mind that one coil fires 2 plugs so if the coils dead you should have 2 dead plugs.

04-14-2015	#1
Dmod81 Join Date: Mar 2010 Location: Colorado Springs CO Posts: 76	Engine Ticking All - need your help. My engine has developed a tick. I drove it on Sunday - embarrassingly I did hit the rev limiter. There were no issues when I parked it. Today, when I started the car, I heard the tick. Video is here: https://youtu.be/jiUyyVhvMvk It does increase with engine rpm, although there gets to be a point where I can't hear it due to exhaust noise. The car does seem to shake a bit. Oil is good and oil pressure is good. I attached my timing light to all of the plug wires, and got only very intermittent flashing on cylinder #6. I plugged in my Tech one, and the R Int is 146 with the L Int at 132. BLM is at 133 for both. Also, the O2 voltages were jumping around a lot. Is the ticking/knocking noise likely the flywheel, and the overall problem likely the coil? Thanks for all of your help.

04-14-2015	#2
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,802	Re: Engine Ticking put a metal tube (like an old brake line) on a stethoscope or to a rubber hose you can stick in one ear and run it along the exhaust flange and any welds that might be leaking on the exhaust system.

04-15-2015	#3
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,662	Re: Engine Ticking A little more information would be helpful like, what year car, miles, mods, what side is the tick on, etc. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

04-15-2015	#4
Dmod81 Join Date: Mar 2010 Location: Colorado Springs CO Posts: 76	Re: Engine Ticking 92, 56000 miles, headers w/ cats/3" exhaust/Haibeck chip. Coils and injectors were replaced (Accels) in about 08, about 7,000 miles ago. I can't hear it very well from the top of the car, but can hear it better from under. Seems louder on the drivers side, but that may just be the garage wall echoing. I'll also use a stethoscope to see if there is an exhaust leak or if there is any discernable noise under the can cover today. So is the no light from the timing light on the #6 cylinder not really a smoking gun then? It just seemed weird that it worked on all 7 of the other wires.

04-15-2015	#5
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,662	Re: Engine Ticking The motor shake would suggest a miss. Which would be consistent with a cylinder not firing as indicated by the timing light. I'd swap the plugs between 4 and 6 and see if that changes at all. Also compare the color of the plugs to see if they look similar. And see what u get using the stethoscope as mike suggested. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

04-15-2015	#6
Dmod81 Join Date: Mar 2010 Location: Colorado Springs CO Posts: 76	Re: Engine Ticking OK, I'll do all of that after work. Thanks

04-15-2015	#7
Dmod81 Join Date: Mar 2010 Location: Colorado Springs CO Posts: 76	Re: Engine Ticking Here's a picture of the plugs, 6 on top, 4 on bottom. # 6 did smell slightly of fuel. I switched the plugs, still no fire on cylinder 6. Nothing discernable/ conclusive heard with stethoscope. I'm trying to look at this as an opportunity to port the top end!

04-15-2015	#9
Dmod81 Join Date: Mar 2010 Location: Colorado Springs CO Posts: 76	Re: Engine Ticking No, I don't see anything. So possibly either wire or coil. I'm going to replace both, I already have a set of wires and a set of gaskets. I figured as long as I'm taking off the plenum, I might as well port since I've been wanting to. I'm also thinking about blocking the coolant as well so it will be easier to pull the plenum again.

04-16-2015	#10
Z51JEFF Join Date: Dec 2007 Location: Fremont,Ca Posts: 3,036	Re: Engine Ticking Keep in mind that one coil fires 2 plugs so if the coils dead you should have 2 dead plugs.