Hey y'all, 2013 sport 5MT @ 120K MI.

I'm getting an inconsistent studded/shimmy/stumble when accelerating from stop. Just did a service, I didn't see any bad bushings, CVs look good, brakes were done recently, new tires, new plugs, valve lash calibrated recently.

My suspicion is the clutch (it's the original). But I'm not getting clutch slip under heavy acceleration. Maybe dirty flywheel?

Any recommendations?

 

120k... Have you replaced the coils yet?
Also, any mods? With a K&N intake my 2010 stumbled, was rough and generally unhappy.

 

here's a I made showing premature spring compression in a clutch. It could in my case be the result of poor shifting in unison with my having done the clutch delay valve delete. I'd recommend (if you havent) also checking out your front brake rotors for warping, and your front brake pads for wear and to see if they have their little spring clip thingies that keeps them spread apart. Oh, and check torque on your wheels 😂 I think that covers the uncommon causes.

P.S. The OEM clutch shown had ~80K miles on it. I much prefer the new Exedy that has a reduced surface area
The Exedy is shown at the top. It's a single spring design instead of the fancier *spring in a spring* set-up.

 

Original coils, new plugs. But I don't have any plug fouling that would indicate bad coils.

I've had a K&N for years without issue, but I can try chucking in a disposable.

 

Yeah I'm leaving toward clutch. But I don't get any clutch slip at high RPM, which should be happening if the clutch is gone. It's friggin weird.

 

I know exactly what you're talking about. I have a 2010 that I bought about 4 years ago with 36k on it and I've had that chattering problem when taking off ever since I had the car, it now has 88k. It's usually worse when it's cold. It feels almost as if the clutch is skipping rather then slipping. The other week here in Jersey we had a hurricane come through and I ended up going through some deep water. I had to go into first and the chatter ended up getting really bad and after I got through the water it did it as I shifted to 2nd. A few shifts and it was fine again. What I didn't get was if the clutch is a closed system, how did water get into it? Or I'm assuming water got in?

 

I can't speculate beyond this car but do have my own hypothesis.
The idea is that the springs in the clutch get compressed and rebound, creating a shudder. Changing my clutch didn't resolve my issue, but did reduce it significantly. I suspect that the clutch overcomes the engine, which may be the unfamiliar element here. The clutch in the fit, based on my walk through summit racing, is similar in design to some upgraded performance clutches that I saw there. The spring in spring deal was advertised as being more aggressive over stock clutches.

I think the OEM clutch is overkill, at least for me. I did cross reference part numbers through Honda suspecting to find that the same clutch was used for other Hondas with larger engines, but that wasn't the case at a glance.

In regards to shudder caused by your hurricane, excess resistance at the wheel can also cause this fault. I've also experienced it as a result of misalignment and separately, warped rotors. Honestly, I think I made the problem worse when I upgraded my wheels to 7" wide Sparcos with AA rated tires. If I'd had the money for lighter (11-12lb) wheels it may have offset the increased resistance.

My clutch had partial failure without ever slipping once, as shown in my post above.