I have a 2013 Si sedan with an occasional hiccup in power delivery. I ordered my car to spec, but test drove a model that exhibited an identical symptom (that I didn't give much thought at the time).
If I am at wide open throttle (or very near WOT) and pass through ~4k I'll get a stutter/hesitation from the engine. It might be accurate to describe it as having the "feel" of a gentle misfire (though I have no indications that a misfire is what I'm actually dealing with).
I induced this problem on my test drive because (coming from a reasonably torquey 3 series) I wondered how the Si's engine would pull in a moderately high gear at sub highway speeds (though I was trying to stay out of an abusive/lugging situation). When I did this test drive experiment, the engine pulled smoothly from ~3k and didn't hiccup until hitting ~4k.
To paint the most accurate scenario of the conditions under which I first observed this issue (test drive), please check on the Google street view location and note the following:
I know that a lot of OEM HP/torque graphs are theoretical or heavily smoothed, but I couldn't find such a graph for this engine. I hadn't done extensive digging for a 3rd party graph until just now, but I did find a 2012 Si dyno plot here (on this form). I suppose this suggests that I'm entering that awkward torque/HP "dip" that happens right around 4k?
Is this recognized as an issue by Honda? Does anyone know if a software fix exists (or is promised to be forthcoming)? Is this some sort of known ECU software glitch? If I could readily replicate the issue for a dealer, is there anything (known) that they could do for me under warranty?
Perhaps this dip is a consequence of the VTEC has has to be "discretely" engaged (vs the VANOS on my old BMW that was an "infinitely" variable design). I usually this symptom isn't apparent, but under just the right circumstances it can be reliably replicated (so if a quick fix exists I'd probably pursue it - but I wouldn't be too bothered to just live with it if pursuing a fix means several trips to a dealer just to end up in the same place I started).
I attempted a search, so apologies if this has been addressed already.
FYI - I did read about the "VTEC plunger" issue keeping a valve open on one of the cylinders. However, my car seems to run otherwise normally with regard to high RPM power and doesn't sound like a tractor.
If I am at wide open throttle (or very near WOT) and pass through ~4k I'll get a stutter/hesitation from the engine. It might be accurate to describe it as having the "feel" of a gentle misfire (though I have no indications that a misfire is what I'm actually dealing with).
I induced this problem on my test drive because (coming from a reasonably torquey 3 series) I wondered how the Si's engine would pull in a moderately high gear at sub highway speeds (though I was trying to stay out of an abusive/lugging situation). When I did this test drive experiment, the engine pulled smoothly from ~3k and didn't hiccup until hitting ~4k.
To paint the most accurate scenario of the conditions under which I first observed this issue (test drive), please check on the Google street view location and note the following:
- I had 2 additional people in the car, so the car was loaded to several hundred pounds above "empty" weight.
- I was coming from the right (travelling downhill in the same direction as the brown pickup truck).
- I was driving through through the "Yield" lane in 4th gear and making the right hand merge onto the other road (gentle incline).
- The car smoothly (but slowly) accelerated under these 3k/4th gear test conditions until reaching 4k RPM (where it hiccuped). After passing through 4k the car resumed "normal" acceleration behavior.
- If the VTEC lights are to be believed as a legitimate reference, at 4k I'd be some reasonable RPM band away from the ~5k VTEC engagement.
I know that a lot of OEM HP/torque graphs are theoretical or heavily smoothed, but I couldn't find such a graph for this engine. I hadn't done extensive digging for a 3rd party graph until just now, but I did find a 2012 Si dyno plot here (on this form). I suppose this suggests that I'm entering that awkward torque/HP "dip" that happens right around 4k?
Is this recognized as an issue by Honda? Does anyone know if a software fix exists (or is promised to be forthcoming)? Is this some sort of known ECU software glitch? If I could readily replicate the issue for a dealer, is there anything (known) that they could do for me under warranty?
Perhaps this dip is a consequence of the VTEC has has to be "discretely" engaged (vs the VANOS on my old BMW that was an "infinitely" variable design). I usually this symptom isn't apparent, but under just the right circumstances it can be reliably replicated (so if a quick fix exists I'd probably pursue it - but I wouldn't be too bothered to just live with it if pursuing a fix means several trips to a dealer just to end up in the same place I started).
I attempted a search, so apologies if this has been addressed already.
FYI - I did read about the "VTEC plunger" issue keeping a valve open on one of the cylinders. However, my car seems to run otherwise normally with regard to high RPM power and doesn't sound like a tractor.
