drain plugs

why don't engine manufacturers put an extra drain plug on the engine block with a valve so you don't have to remove the knock sensors to drain the engine block?

Most do!

Is there a way to drain the block without removing the knock sensors in an '08 monsoon?

That is exactly what i am asking, since they put a knock sensor where the older valve was.

FOr those ppl that keep their boats in the water late in the season, and drain the block every night, i could be a pain. What happens if you mount the knock sensor to somethign else and put a valve in that hole?

I just drained my 08 Monsoon today for the first time. There's a 1/2" nut that holds a the knock sensor on and then the plug is gonna need a 1" wrench or socket if I remember correctly.

The 1/2" nut was so tight on the one side that the drain plug came out attached to everything (really not a problem, less work). On the other side, I removed the 1/2" nut, then the plug.

The housing the sensor plug goes into is almost like a really thick washer.

As long as you don't pull, wiggle, or try to unclip the the plastic plug portion of the sensor the wrong way, it should be hard to do any damage to the sensor.

Hope this helps.

why don't they put a second valve to drain the block instead of having to remove the knock sensors

You do not want to mess with the knock sensors. They must be torqued to spec and are easily damaged. Read the TSB's or any tech article regarding knock sensors to understand more.

Peter, how do you drain the water without removing the knock sensor, I've had Indmar and PCM v-drives both said to remove the knock sensor.