'07 Accord 4cyl w/5mt now has about 175k miles on it. When revving upwards of 5800rpm for more than a brief moment, I begin to hear what sounds like popping in the exhaust, like a carbureted engine would when downshifted, and can see blue/black smoke in the rear view mirror. If I rev quickly to redline in 1st there is no issue, however if I continue on to second and hold full throttle it will begin the smoking/popping around 5800rpm. There are never any warning lights illuminated on the dash and it still feels as though it is pulling strong.
I first noticed this about 30k miles ago and thought it might have been spark plugs since they were originals, so I changed those around 25k miles ago with no improvement.
I have been driving the car easier and shifting around 5500-5600 rpm when I needed for the last year or so and completely forgot about the issue until I had to punch it up hill the other day and was reminded that the issue still exists. It does not seem to be any better or worse than it was 30k miles ago.
Any ideas on what could cause this? I am assuming it must be unburned fuel, but not sure. The only thing I could think is maybe a weak coil pack, but I don't want to just throw parts at it. The car runs flawlessly otherwise and oil consumption has actually decreased from about 3/4qt every 1k miles when I bought it to about 1/4qt every 1k miles with a 10k mile change interval.
I first noticed this about 30k miles ago and thought it might have been spark plugs since they were originals, so I changed those around 25k miles ago with no improvement.
I have been driving the car easier and shifting around 5500-5600 rpm when I needed for the last year or so and completely forgot about the issue until I had to punch it up hill the other day and was reminded that the issue still exists. It does not seem to be any better or worse than it was 30k miles ago.
Any ideas on what could cause this? I am assuming it must be unburned fuel, but not sure. The only thing I could think is maybe a weak coil pack, but I don't want to just throw parts at it. The car runs flawlessly otherwise and oil consumption has actually decreased from about 3/4qt every 1k miles when I bought it to about 1/4qt every 1k miles with a 10k mile change interval.