Clutch Vibration/Bent Connecting Rod

[John Goodman]

New owner of a 2013 Speed 3, seems stock or at least returned to stock. I've been reading up on different issues to look out for as the vehicle is in pretty excellent shape despite having ~100k on the odo and I want to keep it that way.
In my reading I've seen to be wary of clutch vibration as this is a sign of bent conrods. With the clutch pedal fully released, if I push it just enough to take up the slack at the top, I can feel a minor vibration that changes with engine speed. With other vehicles I've driven this feels about right, but I'm understandably a little paranoid about adding unwanted ventilation to the block in my new ride.
I pulled the TMIC and plugs, dropped a long extension in each cyl and turned the crank until they topped out to get an estimate if one stroke is particularly short and they were all the same.
So now I'm left with the following questions; How much, if any, clutch vibration is "normal"? Are there other causes for this vibration that I can safely ignore or fix with less effort than rebuilding? Is the quick stroke length estimate good enough to feel "safe" to drive without fearing the ZZB?
Thanks for reading, please let me know what you think!

 

[DISIFTW]

It's hard to tell a slight bend tell using the long extension method; best way is to drop the oil pan and visually inspect. The slight vibration in the clutch could be a few things, is it the oem clutch or aftermarket? It also could be nothing at all.

 

[John Goodman]

It's hard to tell a slight bend tell using the long extension method; best way is to drop the oil pan and visually inspect. The slight vibration in the clutch could be a few things, is it the oem clutch or aftermarket? It also could be nothing at all.

I was wondering myself if the clutch plate is OEM or not. I'm going to be doing the VVT tomorrow so while I have it up on jacks I can crawl under and peek at it if there's an inspection plate or something. Any advice on what to look for in that regard would be appreciated.
I can drop the pan too if I'm down there. Would you happen to know if I would need a new gasket if I do so? If so I might grab one first and do that next weekend.
Thanks for the reply!

 

[DISIFTW]

There's not an inspection plate to see so you would have to separate the block and trans. As far as oil pan, there's not a gasket its rtv. If you go that route make sure to completely clean the old rtv off the pan, block, and rear main seal and be generous when reapplying around the rear main seal as that's a common area for leaks. Personally I use permatex "the right stuff" rtv because it has a shorter cure time, but use what works best for you.

 

[John Goodman]

Awesome, that's exactly what I wanted to know. Thanks for the info! I'm probably not going separate the transmission just to look and see what's in there, but I can definitely pull the pan soon. Maybe I'm the only one paranoid enough to be worried about such a small vibration, but I've had a hard time finding any similar posts on this on here or online. So whatever I find I'll be sure to report back for others to study.

 

[Easter Bunny]

I wouldn't take the time to do vvt until you have investigated the vibration. No sense doing all that work on a blown motor. If the vibration is a bent rod it will get worse pretty quickly

 

[John Goodman]

I agree with you Easter Bunny, and in fact that's why I wanted to ask for info here before starting on the VVT. Updating the thread like I promised; dropped the pan and inspected, all 4 conrods looked good. Also did a compression test, 180psi on all 4 cyls. With renewed confidence in my bottom end I also went ahead and did the VVT job. All's well there, nice tight chain now and no codes or leaks. If anyone finds this searching for info like I was, dropping the oil pan and re-sealing it is pretty easy and it's worth it for the peace of mind.