Blue/Black Smoke and Popping @ High RPM

Joined
May 19, 2018
Messages
98
Location
CT
'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.
 
shifting at 5600 is easy?

possible valve adjustment needed.. and if you drive it that way all the time I'm sure it needs some other parts.

blue smoke is usually oil, black smoke unburnt fuel.
 
Could be valves, you could need plugs/ wires/ coil, could be an injector going bad.

When the last time you adjusted the valves?
 
UncleDave is correct, any or a combination of them could be your problem. I remember working with a Customer for months on misfires, my research revealed, valve seal issues and even though he was out of warranty he played nice to his service manager and got the heads replaced for free.
 
shifting at 5600 is easy?

possible valve adjustment needed.. and if you drive it that way all the time I'm sure it needs some other parts.

blue smoke is usually oil, black smoke unburnt fuel.
Well, ya. 5600 is well within the operating limits, 900rpm less than redline, and it's not being held there for any extended periods of time.

It's hard to tell the color of the smoke exactly because I have only noticed it in the rear view mirror.

Sounds like a valve.
I had not considered this, as I have owned cars over 230k miles and never touched the valves. Upon doing a little research it sounds like this car may require adjustments. I think you and Rand could be on to something. Thanks.

You're beating the hell out of it as it is. What were you shifting at BEFORE you were easy on it? No wonder it's smoking, it's worn out before it's time.
People on this forum are very quick to judge. Did I say I was tracking the car or doing this all day every day? We are talking a few times a week, sometimes to redline. Public roads here, but it's 4cyl that likes to rev and I'm located in a hilly area.

If it's worn out before it's time wouldn't it be using more oil, not less? Shouldn't it be using more fuel or smoking all the time, maybe making some off noises? The car runs like a champ and I don't drive it any differently than any other car I have owned and I have never had an engine problem.

Let's hope it wasn't revved that high before being fully warmed up.
RPMS under 2600 - 2700 rpm for the first 5 minutes then under 3500 for the next 10. Never get on when cold. Only exception is if I have to get on the highway right away, as it turns a little over 3k at 75mph...

I may run my cars hard every now and then, but I don't abuse them.
 
OP, nice stable of cars. Any pics of the '84 Biarritz and history of it?

Thanks!

Not a whole lot of history on the Biarritz. I know it was first owned by a Doctor/Surgeon. A medical logo he applied is still on the right rear of the trunk lid. It was acquired by a family friend in the late 90s and then purchased by my late father in law around 2010. Upon his passing about 5 years ago he left the car to my daughter (his granddaughter) who is still in grade school and too young to drive it. My wife and I have agreed to care for the car until she is ready to drive it. We try to run a few tanks of gas through it every year, She loves going for rides in "Her Cadillac."

I will have to try to get some decent pictures of it to post. It is going in for some "body work" over the winter, basically to replace all of the cracking rubber pieces on the body that have started to dry rot. We were able to source some fiberglass replacements that will be painted to match. Otherwise the car is clean inside and out and is a great cruiser.
 
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