What do u guys think

[96 runner]

I just bought a 96 4 runner
It's got about 150k miles on it
4 wheel drive manual trans
There's a slight knocking sound
And spits out a white/ very slight blue smoke
I was just wondering if anyone got any ideas
One guy said it's the knock sensor
Another says water pump
I figure I'd get on this forum and ask the pros
Thanks aloha

 

[chetJ]

Coolant getting into the exhaust somehow? The white smoke should be that - I think

 

[004Gunner]

Post a vid or link to one that captures the knocking sound. You may want to search Youtube for '4Runner knock' or something similar. The color of the smoke is important, but so is where it comes from (i.e. exhaust @tailpipe or manifold, engine @head or block)