I have a 97 Expedition with a 5.4. Noticed white smoke that smells like antifreeze. I did a compression check on the motor. All cylinders range from 160 to 170. I then pressurized each cylinder with 100psi of air from my air compressor. I made sure each cylinder was at TDC while I did the check. I found that #5 cylinder would not hold the pressure and I could hear the coolant gurgling and my coolant reservoir and then it then it built up pressure. I now know that I have a bad head gasket but what I am puzzled about is that when I did my compression test, the #5 cylinder came in at 165 on my guage. I am now wondering if I should do a head job on my motor or drop in a used rebuild instead. I have 205,000 on it now. Any input would be appreciated to help me make up my mind.

 

It's NOT white smoke. When water boils it turns to steam not smoke.

 

It didn't look like it was just steam. It was a white smoke that stayed in the air for awhile. And it smelled like antifreeze.

 

You have good compression, your exhaust is white and smells like anti freeze and then you did a leak down test that showed #5 was leaking into the cooling system. It sure sounds like all you need is a head gasket replaced and while you're in there you should replace the timing set-up at the front as you have likely passed the time where they usually fail. That is the chain guides, chains and Tensioners.