My 96 blazer is losing antifreeze and there is no visible leaks. I also have a very rough idle on start up after its been sitting, it then goes away after a minute.my question is. is this an intake leak or head gasket?

 

Head gasket problems are not common on this engine unless you really cook it! You'd notice other things like serious steam from the tail pipe all the time, radiator hoses getting hard as a rock, constant misfire, etc. Very common on this engine for the lower intake manifold gaskets to leak. Coolant can drip onto an exhaust manifold or crossover pipe and burn off instantly, you'd never see it. Intakes can also leak coolant internally allowing the coolant into the oil. Check for leaks where the intake meets the cylinder head on both sides, and check for coolant in the oil.

 

These were well known to have intake gasket leaks. I would bet good money that's your problem. Don't leave it go, you'll end up ruining your engine. I just replaced the one in my sister's 96 a month ago with the same issues, only she continued to drive it and the oil turned to chocolate milk mess. No matter if you do it yourself or have it done, make sure you have the good Fel Pro gasket installed. It will last much longer.

 

Thank you for the tips on where to look. Because I'm loosing anti freeze but have yet to find a leak. Now I know where to look.

 

Yeah better check the engine oil. may be leaking internally into the engine and that is bad news for the bearings.

 

Mine leaked down the back of the engine onto the transmission and I never noticed it.