We built a new house last year and are having problems with crackling and popping noise from our engineered floor. You can feel the floor move very slightly when walking on it without sock The product is 3/8" thick by 4" wide. It was stapled down over roofing felt to 3/4" OSB subfloor. The installer said he glued the T&G (edge glued) the pieces. The joists are engineered and spaced 20" on center. The noise pretty much all over the floor but worse in some areas. We've had several installers to look, but nobody has been able to come to conclusion on why the floor is making noise. One thing I will note is that during the building process our sub-floor got soaked several times and sat under an inch or more water for a couple of days. The sub-floor makes some noise under the carpeted areas as well (i.e. sounds like the seams rubbing together) but the sound is different . Any thoughts or suggestions? Are the 3/8" thick products too thin for the sub-floor joist combo that we have. Any advice will be GREATLY appreciated!

I'm thinking you answered your own question giving us the info about the OSB being wet. Your only going to find the answer by destructive examination to see if the fasteners are loose in the affected areas.
Anyone check the moisture content of the OSB and wood prior to installation?

I don't think anyone tested the moisture content of the OSB or wood floor. The OSB was allowed to dry for about 6 weeks prior to installation of the floor. The floor was brought to the house 2 days prior to installation.

I just am amazed that installers and dealers think a period of time will provide the correct acclimation. Only meters adjusted to the species of wood will do that. Amen