So last year i had some work done to my 4.6. New cam and headers and tune. Now I'm noticing when i get on it. I smell coolant and it's blowing thru the exhaust. Sometimes i can really see white smoke. Other times i can't. It loses some coolant. But nothing terrible. But there is no leaks i can find any where. I had the coolant system pressure tested. And it passed at a 100 psi. Held it for a oil change and rear end service. So I'm at a loss at what can be happening. It doesn't over heat. And doesn't run funny. Any suggestions?

 

You out 100 psi through the cooling system??? White smoke means coolant is getting in to the combustion chamber. Most of the time it's a bad head gasket. I guess it might be possible for the intake manifold gasket to break between the cross over passage and the closest intake port. You're not leaking coolant into the valley or the back of the engine?

 

I cant see anywhere that it is leaking on the engine. I'm leaning towards the head gasket or something. I just dont understand. It runs fine unless i beat on her. Then it starts blowing coolant thru the tailpipe. But thank you for your input

 

I've seen that happen. You might be able to do a block tester after you beat on it to verify. Just be careful because the coolant will be hot and pressurized.