Questions about the GM Top End Engine Cleaner

[1BADHD]

I went to the dealer and picked up two cans. I dont have the knock very bad at all, but I figured what could it hurt. My questions is, why cant you just take out the spark plugs and spray it directly into the cylinder. Seems to me that it would be very concentrated and work better that going through the fuel system. Or would that wash to much oil off the cylinder walls and the rings? Just wondering.

[bcfitzsimons]

You can do that.  Supposedly, that's how a lot of dealers do it.  Just make sure that if you do that, that you crank the engine over a few times before you put the plugs back so you push the remaining top end cleaner out of the cylinder.  If you don't, you may end up with hydraulic lock.

 

Fitz.