This topic contains 0 replies, has 1 voice, and was last updated by Avery Boyer 1 year, 1 month ago.
I’m a bit stumped with my 1997 Civic (D16Y7) that I just did some work on. It started smoking after sitting for a couple of months while I did an extensive overhaul of the suspension and engine. A basic overview of what I did to the engine:
New timing belt, water pump and drive belts (Gates)
New valve stem seals (Enginetech)
Valve cover gasket replacement (Fel Pro)
Oil pan gasket replacement (Fel Pro)
Replaced plug wires and spark plugs (NGK)
Replaced the fuel lines (Lines To Go)
A little history of the car: I got it at 239,000 miles and it’s now at 298. I did a compression test when I got it and got 185-195 psi across the cylinders. I’ve generally kept up with maintenance, including oil changes and valve adjustments. It has a history of using oil (mostly leaks) and smoking significantly at start up. That is what prompted me to replace the valve seals. The timing belt was done shortly before I got the car so I was a little ahead of schedule there. It had no history of smoking under acceleration or in any significant amount after about 30 seconds of running.
So after I finished the work, I started the car and immediately it started smoking. It smokes noticeably but not significantly at idle, increasing steadily with increased RPM. It does not taper off as the engine warms. As far as I can tell it does not smell like coolant or raw fuel. I have opened up the throttle body and found oil pooled in the intake manifold. If I clean the oil out, the car smokes less at first, but then it increases back to the same amount as before after a minute or so of running. Some amount of oil then reappears in the manifold.
What I’ve done to troubleshoot:
Confirmed the timing is correct: It is
Compression test: 185-195 across the cylinders-the same as when I got the car
Cleaned and checked the PCV valve
Checked coolant: No obvious loss of coolant and no oil in the coolant or vice versa
Pulled the spark plugs: all were sooty, but only #2 cylinder looked distinctly oily
Checked the oil level: Normal. I had to add a little more than usual (about exactly 4 quarts) and the dipstick is reading a little low BUT I cleaned the oil pan so I imagine that has something to do with it.
I doubt it’s the rings because as I said, this is a new and very sudden problem and the compression hasn’t changed. I have not done a leak down test but that may be the next step. As far as the headgasket, I am more willing to believe it would fail suddenly but that doesn’t explain why the compression is normal (for this engine). The main suspect in my mind is the valve seals. But I feel confident that I seated them correctly. I did have trouble getting the old seals out but as far as I know I didn’t damage the sealing surfaces or valve stems. It also seems like a ton of smoke for it to be the valve seals-in my mind almost all of them would have to be bad to make it smoke that much. Here is a link to a video of the car running and the smoke it is producing:
A few additional notes: The car seems loud, especially inside the cabin where I can feel the vibration of the engine much more than before. I haven’t tried to troubleshoot the problem because I figure whatever is going on with the smoke could be making the engine run rough and if I fix the smoke and it still seems loud and vibrates a lot I can deal with that as a separate issue. I am trying not to go down the rabbit hole or chase my tail excessively. I also did change most of the motor mounts.
I’d be very grateful for any help diagnosing this problem. It’s a mystery to me and I don’t have enough experience to keep going troubleshooting without starting to just guess a little bit, which I’d like to avoid.
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