Loss of power and big puff of white smoke
 

I have an 02' with the 4.7 with 164k. At one time I was getting code p0300 and truck sounded rough. I did a compression check, changed all plugs and coil packs and bought a code reader and erased the light and code. Code hasn't come back but every now and then, the truck will act like it won't turn over when cranking when finally starts will give big puff of white smoke out exhaust and has low to no power for just a minute, then back to normal but with no codes or lights. I'm thinking injectors but with no code I don't know what injector to start with. Any ideas?

You could try some gas additive that cleans the injectors. Go buy 3 bottles of Techron (autozone should have it), run tank to 1/8, add 1 bottle, fill with super unleaded to 1/2 a tank. Repeat this process until you have used all 3 and run to 1/8 again. Then top off tank with super unleaded when finished. This cleared up my Durango.

SJ03

White smoke is usually coolant. Head gasket blown?

Compression check was good so I'm guessing gasket is ok. I am a diesel mechanic and white smoke to me is almost always fuel.

Also I use seafoam about every other month in fuel and in intake did it once.

Probably a result of the seafoam. When it does it, try going WOT to blow it out?

SJ03

Valve seals leaking?

On a diesel, white smoke could be fuel. On a gasser, fuel is black.

Pulling heads....
 

Ok so as it turns out there is either a blown gasket or a cracked head on the ram. I was meddling with it today and just happened to pull the plugs again to do a more indept comp check and what do my eyes spot that I didn't last time? Water on top of number 2 and 4 Pistons. I could actually see with a flashlight a drop of coolant every 4 or 5 seconds. So..... How hard is this job to complete? I am a mechanic but on diesel not gas and never really messed with over head cam. Do I need any special tools to get the cams off and on? Any help would be awesome.