Intake Gasket? Head Gasket?

[paulson524]

Ok so I have a 99 Tahoe with a Vortec 5.7, I'm losing coolant slowly and I'm getting some white smoke out of the trail pipe. And while driving it chugs along with no power feeling like it's constantly misfiring. Compression is between 145-150 psi on all 8 cylinders. Oil looks good. I got a block tester kit from Autozone and it doesn't show Any leaks in the coolant system. Plugs don't look bad but I'm getting P0300 code. Any ideas help. Thank you.

 

[supermailman]

I have a similar problem but with a TBI truck. Coolant is getting into my exhaust but only on the driver's side bank. My oil looks pristine. I pulled the exhaust manifolds away and confirmed, plus I have true duals and was getting white/gray smoke from that side's tailpipe. Getting a code 45 for rich exhaust plus had a healthy misfire but that ended up being a plug wire that wasn't properly seated. I am replacing the intake manifold gaskets and the exhaust manifold gaskets to see what happens.