White smoke coming out of exhaust. 1993 honda accord. I'm not sure why this happened. It happened not too much time after I replaced cat converter exhaust pipe.
I don't know why but I think it was the cat converter exhaust pipe. It was a performance pipe on ebay. I heard a strange noise from the exhaust pipes a couple of times from that.

But I'm getting some real bad signs here. It doesn't go away after its warmed up. It doesn't seem to be over heating.
Yes there is a strange white residue inside the engine oil cap.
And then I think I seen a tiny bit on the engine dipstick. But when I rechecked it by wiping it off with a paper towel. I didn't see anymore.
And with the engine cap off air is coming out.

Is there anymore tests I need to do to confirm what it is? From my research it seems to be a blown head gasket. Or a piston ring. I don't smell anything strange from the white smoke. I either narrowed it down to those two. Hmm.

Edit:
Maybe if I'm lucky this is possible, this started happening or I started noticing this in the winter. And I haven't been using the car in a while. My gas tank wasn't that full. Maybe water got into the fuel system and it wasn't coolant in the engine oil. Maybe I can fill it up more. And if I keep running it for more than 30 minutes. Maybe the white smoke will go away and it isn't a head gasket problem. I guess what's left to ultimately confirm it is using a block tester.

I just find it hard to believe that the head gasket blew when I wasn't even (Too busy repairing it) using it too much. And it never over heated which would cause the head gasket to go bad.

I guess I could check the spark plug wires as well. Maybe I can take the valve cover off as well. I guess the first thing to try is block tester.

 

A block tester will be definitive.

You could try pressure testing the radiator to see if coolant is getting inside the cylinders?

 

Yup, I'd check with a radiator pressure tester. This time of year, it's hard to just say it's 1 thing or another, due to the colder temps, that can cause condensation to mix inside the engine (due to it being warmed up and allowed to cool overnight). Are you noticing a drop in coolant level?

 

Yeah, I just tried the block tester. It was a negative (color stayed the same). I did a little research on this and this is what I found "White smoke from an automobile can be caused by three things: condensing moisture, heated coolant and vaporized fuel."

So it isn't a heated coolant leak.

I ran the car for 15 mins more. I think I will make a video. Maybe fill the gas tank half full and run it for 30 mins. Then record a video of the white smoke. I'm not sure what it should look like that. I took my work truck and it doesn't have nearly as much white smoke after it warms up.
There is still many things it could be although.



No drop in coolant, and no bubbles in coolant either. It could be condensation. But isn't condensation suppose to go away after the car is warmed up?



One guy on a youtube video said this
"If the piston rings are leaking too much then you will get a continuous positive pressure from your oil cap opening. You can check that one out really easy with a feather and a piece of cloth. Just stretch the cloth over the opening and hold the feather above the cloth so you can see with your own eyes if there is a continuous stream of air coming out of it. If no then its not the piston rings If yes then its the piston rings which are shot."

I'm not sure if this true, hmm.... Toecutter, could you check to your honda accord and see what the air is like when it comes out? Is it constant or does it go back and forth?
Then again, if a piston ring is bad, wouldn't you hear something in the engine?

Another thing I saw from another video is that someone said if you get air out of the dip stick tube while it's idling that is bad ring? I should check mine on that.

 

HI quick test for HG faliure take plugs out and shine light to see top of piston on each cylinder if you notice one looks alot cleaner then there will be your problem water cleans piston a treat so a clean piston is the sign of HG failure.