I am selling my 1997 civic with a d16y7.
Compression: 200 195 190 200
Problem: Lots of white smoke when revving. It smells a bit like fuel, not really sweet, and definitely not like burnt oil. I never noticed it before washing the engine, but I never really sat in it and revved it.
I washed the engine with water from a jug, nothing high pressure or spraying everywhere. When a guy came to test it he started it up and revved it up, and it was really blowing a lot of white smoke. There is no visible smoke when idling, hot or cold, but when revving, it makes a pretty good cloud that disappears fast.
Also, for about 20 min, it would really hesitate anytime I accelerated hard, but then that went away and now it sounds fine and drives fine, aside from the smoke when revving.
I took off the rad cap, and there are no bubbles or anything when idling, and the compression is good. There is no loss of coolant or brake fluid over the last year.My coolant and oil stay the correct color and are definitely not mixing.
My spark plugs are all light tan with no wetness or flaky deposits.
It has been fully warmed up and driven, so water on the exhaust should be long gone.
I noticed my radiator cap was broken, the spring and other parts broke off. I will replace it this week.

Does anyone have any ideas of what it could be? It seems like my head gasket is probably fine, could the water have gotten into anything that would make it smoke only when revving, several days later?

I am planning on doing a block test and a leak down test if there are no other ideas.

Thank you for your help

 

Is it cold out?

 

Its cold everywhere!


Probably condensation in exhaust like what ^he was pointing out

 

exhaust is hot...its cold...

 

Billowing clouds of white smoke, only when revving. Whether the engine is cold or hot, or has been running for 2 minutes or 1 hour doesn't change anything. It is about 10 degrees Celsius, not very cold at all. Condensation in the exhaust would have burned off after 10 or 20 min, and if it was due to the cold it would smoke at idle, not only when revving.

I thought it might be running really rich, but the spark plugs look ok and it runs well.

 

I don't think you have any issues, it's cold out. 10 C is plenty cold, maybe not freazing but definitely not like 24 C.

People seem to forget what the catalytic converter does. It burns the exhaust into CO2 and Water vapor. Hot moist air, cold outside air. Revving means even more hot moist air.... Means more poofs of steam vapor.

If you have no loss in power, no loss in coolant, no loss in oil, no cross contamination in oil or coolant and it runs well and gets the same gas milage, your car is more than likely perfectly okay.

 

^I will agree with the above.

A car running rich will create more condensation. If there isn't a CEL on, it probably isn't running that rich. So...the car is most likely fine.

10°C is plenty cold enough to create condensation....especially if it's relatively humid.

 

Thanks for your replies,
It is fairly humid here.

Would somebody that reads this be willing to test this out for me? Start your car, rev to about 3000, and see if you have a cloud of light smoke the same size as your car in about 15 seconds?
It is currently 5 C, 85% humidity here.

Thanks
Lars