.1 engine clicking/knocking noise
#1
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Join Date: Feb 2012
Location: Morehead, KY
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997.1 GT3 engine developed a nasty noise at the track the other weekend. Noticed after the end of the session as I was driving back to garage - plugged in cheapy OBD-II reader which read cat faults (aftermarket cats), and misfires of cylinders 1, 4, 6. Oil level, pressure, coolant temp, etc all fine and car ran good on track (no money shifts - I typically short shift it around 8k). Oil filter clean, no metal debris, oil color/translucency good. Put it on the trailer and came home early ![Frown](https://rennlist.com/forums/images/smilies/frown.gif)
engine miles=12k (mostly track)
Fabspeed headers/cats/exhaust, BMC intake, chip (all done very early by previous owner)
number of ignitions, range 1 = 33 (from previous owner - no over-revs in the higher ranges)
shop where I left car is backed up so I thought I'd hit up RL for suggestions
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engine miles=12k (mostly track)
Fabspeed headers/cats/exhaust, BMC intake, chip (all done very early by previous owner)
number of ignitions, range 1 = 33 (from previous owner - no over-revs in the higher ranges)
shop where I left car is backed up so I thought I'd hit up RL for suggestions
#5
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Ched, that's terrible luck. Could actually be something dumb. Check little things that are known to go wrong with these cars.
Plugs are known to come loose. Crank pullies come loose.
As others suggested these things tend to have pressure plate, throw out bearing problems but it would show itself in functionality when driving back into the pits so I doubt that's an issue but at the same time could cause misfire codes since the flywheel has the crank trigger on it.
I don't think any of the old 3.6L cars had issue with cam bolts backing out.
Struggling to think what else it could be...at least anythign else that doesn't end with a trip to Sharkwerks for a 3.9 conversion
Plugs are known to come loose. Crank pullies come loose.
As others suggested these things tend to have pressure plate, throw out bearing problems but it would show itself in functionality when driving back into the pits so I doubt that's an issue but at the same time could cause misfire codes since the flywheel has the crank trigger on it.
I don't think any of the old 3.6L cars had issue with cam bolts backing out.
Struggling to think what else it could be...at least anythign else that doesn't end with a trip to Sharkwerks for a 3.9 conversion
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#8
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hard to tell from the video, check any external moving parts as it's rpm related.
like pulleys, belts, anything that can have friction. Hard to tell from the video, if live, it would be easy to identify if it's a rod knock or engine related.
like pulleys, belts, anything that can have friction. Hard to tell from the video, if live, it would be easy to identify if it's a rod knock or engine related.
#9
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I'm telling you, I just had a CEL giving misfire codes, and plugs fixed the problem.
My car sounded just like that. I first checked the coil packs on the misfiring cylinders (and they were fine), so next is plugs, which fixed everything.
I almost guarantee you it's a coil pack or spark plugs (or both).
Also, check your exhaust system for leaks, which causes the accelerated wear of coil packs and plugs.
Check the low lying fruit first.
My car sounded just like that. I first checked the coil packs on the misfiring cylinders (and they were fine), so next is plugs, which fixed everything.
I almost guarantee you it's a coil pack or spark plugs (or both).
Also, check your exhaust system for leaks, which causes the accelerated wear of coil packs and plugs.
Check the low lying fruit first.
#11
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I'll be there Labor day for sure for a single day lapping event. Beyond that OVR and NOR's Mid Ohio events are strong possibilities as is KY's Putnam event but I won't be able to do Friday's with any of them for the rest of the year which stinks.
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Just wondering do you have a LWF as well? In any case I would have someone check your cam-adjusters. See if the screws are backing out (another crap design). At least drain the oil and see if you have aluminium shavings (that'll be from the housing as it gets carved away).
#14
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Any loss of power while on track? With a failed coil pack it would be very noticeable power loss. I had cylinder 6 misfire due to bad maf and visually spark plug #6 had a lot of carbon bu. For example normally at brake zone of t1 at thill I'm at 135-138 mph range I was stuck at 114-118 mph. Mike
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