3 or 4 knocks at cold start up only

[BigArt]

Hey Gang. I've searched this and other forums and found nothing. Although I don't post much, I "snoop" around in this and the "other" forum all the time for the last year or so. Lots of knowledgeable people and ideas out there.

My truck gives me 3 or 4 knocks which seem to be coming from the passenger side on cold starts only. By cold starts I mean about 5C and it's been sitting all night. And I get a more than usual "puff" of white/grey smoke. And it doesn't happen with every cold start either. Maybe 1 in 4. After it starts, it smooths out and runs like a champ. Any ideas?

 

[matuva]

I think may be a worn injector leaking.

Check for that. Usually leaking injector are not a good thing, not only concerning mileage and performance, but also because of the fuel sitting in the engine.
Some drops of fuel wait in the combustion chamber, that could explain the few knocks upon start up at cold (wich means after longer time than during daily restarts), and grey puff (unburnt fuel).

my .02

 

[North Maine]

also could be one glow plug not working at all.