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I have developed a cylinder 6 misfire at idle. It occurs with a corresponding non-periodic ticking sound in that area.
Raising the RPM to 1k is enough to stop it from happening.
The only way I can describe the sound is that it sounds electrical in nature, like that of a spark plug firing. But its quite loud so it could also be metallic.
In the video it starts happening at the 0:06s mark, then again at 0:35s and again at 0:55s.
In the following thread in Facebook there is a video with the same random ticking noise.
https://www.facebook.com/595599953/videos/1118309445622613/
In this facebook thread people mention it can be caused by the throttle butterfly. I am not so sure.
In my case the noise appears only when the following two conditions happen:
- The car is fully warmed up
- The car has been driven hard or has been idling for a while (from this I understand that it's because some components get hot in this situation)
Mine happens right away, cold or hot. But only at idle. Raising the engine speed the smallest amount above idle stops it from happening. Definitely not the throttle butterfly.
You very well could have a misfire and need everything replaced but I believe that noise is the purge valve ticking. It lives just behind the engine on the RH side. And both the V12 and V8 have the same one, same location. Some are loud and a few are very loud. Get the car on a ramp and have a peek whilst running. You can physically touch it to be certain that's the source. That's where my money is, blaming it on the purge valve.
You very well could have a misfire and need everything replaced but I believe that noise is the purge valve ticking. It lives just behind the engine on the RH side. And both the V12 and V8 have the same one, same location. Some are loud and a few are very loud. Get the car on a ramp and have a peek whilst running. You can physically touch it to be certain that's the source. That's where my money is, blaming it on the purge valve.
Interesting. Thanks for the tip. I'll have the car up on the lift today and poke around. Not sure where to look for the valve but I'll follow the sound.
The coils and plugs have like 2k miles on them. I can believe that maybe one of the coils is a dud but why does the ticking (if from the purge valve) coincide with the misfire? And that too only show up for Cylinder 6? I had suspected maybe it was a fuel injector. I plan on moving the injector from #6 to #1 as well to see if the misfires move before going through the work of pulling the manifolds again.
Didn't know coils/plugs recently done. Perhaps bad new coil, connection or something of that nature. Injectors are pretty good on these cars. Valve is mounted on the body/frame rail just to the right of the collector on the exhaust manifold.
Is it this black plastic thing with the green fitting on it. If thats the purge valve, I don't feel it clicking at all. And I don't think the sound is coming from that. To my ears it feels much higher up.
Swapped #6 and #1 injector and it made no difference.
But I was right about the sound, it is a spark! I can sometimes see the spark under the manifold, in this area in the photo. Not for every tick, but some ticks I can see it spark. I tried to capture it on camera but it didn't work.
What in the world could it be? And why does it completely go away once I'm out of the idle program. Even the slightest increase to 900-1000rpm and it stops happening.
FWIW- Last year after new coils and plugs, discovered one the new plugs had a hairline crack that caused a similar issue. Didn't observe a spark. Found with OBD showing misfire of a cylinder. Best of luck with yours.
FWIW- Last year after new coils and plugs, discovered one the new plugs had a hairline crack that caused a similar issue. Didn't observe a spark. Found with OBD showing misfire of a cylinder. Best of luck with yours.
Thanks for the input. I already have spark plugs as I bought 4x 4 packs.
Did you replace your intake gasket when you pulled the manifold the second time to replace the spark plug?
V12Stealth... There's a bundle of ground wire that bolts to the cylinder head in the location you circled. I understood that it might be for the right-hand bank of coil grounds, but it could be for something else. I wonder if one of the wires broke or the bolt is loose.
V12Stealth... There's a bundle of ground wire that bolts to the cylinder head in the location you circled. I understood that it might be for the right-hand bank of coil grounds, but it could be for something else. I wonder if one of the wires broke or the bolt is loose.
Thanks for the input. I already have spark plugs as I bought 4x 4 packs.
Did you replace your intake gasket when you pulled the manifold the second time to replace the spark plug?
Was your issue only at idle like mine?
No, Did not replace new gasket. I was not able to hear your issue on the vid. You might as well look at all your wires and PVC while you have things apart. Look at all the rubber hoses too. The heat is a killer under there ! I'm sure there is interest in what you find, It's how we all learn!
Thanks for the input. I already have spark plugs as I bought 4x 4 packs.
Did you replace your intake gasket when you pulled the manifold the second time to replace the spark plug?
Was your issue only at idle like mine?
No, Did not replace new gasket. I was not able to hear your issue on the vid. You might as well look at all your wires and PVC while you have things apart. Look at all the rubber hoses too. The heat is a killer under there ! I'm sure there is interest in what you find, It's how we all learn!
