Rep Power: 0

I have a 1995 Honda Civic, when I’m driving it. It’ll lose power and start slowing down like if it’s in neutral. Once I put a key or something in the shift lock release thing next to the lever and put it back in gear, it’ll move again until it happens again.
what could be the cause of that and what could I do to fix it?

 
Rep Power: 242

So it's slipping into neutral while you are driving? The engine still revs correct the car just won't move?

 
Rep Power: 0

Yes, correct

 
Rep Power: 242

Can you shift it into Park and Drive without pushing the brake pedal?

There is a solenoid that is suppose to lock the shifter in place. Not sure if it is only used when in park. My old Accord you could shift down into lower gears 3,2,1 by just bumping the shift lever but neutral I think you had to push the button on the side of the shift lever. Maybe that is bad.

https://www.hondapartsnow.com/parts-...ect_lever.html

 
Rep Power: 0

Yeah, I can shift through gears 321 by moving the lever without pushing anything. And when I’m driving, I won’t even be touching the lever and then the neutral issue happens. The only way it won’t randomly go into neutral is if I leave a key or something pushed down in the shift lock release spot that’s next to the lever.

 
Rep Power: 242

Then I'd pull that section out and see if anything is out of place. Might be something going on with the release mechanism.

 
Rep Power: 0

Thank you, and one more thing. It started smoking really bad from the exhaust a week or so ago. Any idea what that could be?

 
Rep Power: 242

What color is the smoke?

 
Rep Power: 0

White

 
Rep Power: 125

You're burning coolant, which is a bad sign. First thing would be to check all your coolant hoses to make sure they aren't leaking, but chances are you either have a head gasket failure or a cracked block.

Also, double-check how much coolant you have. How does the level look inside the radiator and overfill reservoir?