I have a 99 5.4L Expedition 2wd. A couple of years ago, I had the truck start to run rough and it started to blow a lot of smoke. I took it to a shop and they said it was a blown head gasket. I don't know if they just guessed this from the symptoms or actually did a compression test but their quote was almost $3,000 to fix it so I took it home and did it myself.

I replaced both head gaskets and all other associated gaskets with a fel-pro kit, I replaced the head bolts and I had both of the heads machined flat. I noticed no cracks or obvious damage in the original head gaskets before I replaced them. I thought this was odd, but being a little dumber at the time, I proceeded on.

After completing the job, the truck ran great again for 1 DAY! It shortly returned right back to its original problem. Eating coolant and blowing tons of smoke out of the exhaust. I needed it to drive as I was moving across states a week later so I went and bought Blue Devil head gasket fix after reading good reviews. That stuff worked like a charm. No smoke or coolant loss for 2 years until now.

The leak has returned and it left me stranded on the side of the road last week. I use this truck to get to work everyday so I went and bought the blue devil stuff again, couldn't stand to have it down for long. One of the steps of the blue devil is to back flush the coolant system before use. I did that and decided to check my oil before doing the blue devil process. Thank god because the crank case had more water in it than oil.

I changed the oil, completed the blue devil process and I was back on the road again but it has started to smoke again already. I assume wherever the leak is has gotten bigger and the Blue devil can no longer seal it.

I need to get this truck driving again and would prefer to actually find the leak instead of pouring another $100 worth of blue devil in it.

The obvious points of leaking could be from:
head gaskets
cracked block
cracked head

Where else could coolant be leaking into the cylinders from?

Is the intake manifold a possibility?

Currently, it is pumping water out of the exhaust while blowing a huge amount of smoke so I am not driving it.

 

intake manifold could pump water into your cylinders but it would definitely cause your vehicle to misfire and run like crap and with an intake leak you shouldn't have too much oil in your coolant unless your rings are toast.. More likely if its not the head gasket its gotta be a cracked block or head,

 

If you changed the head gaskets and the problem reappeared, the heads themselves or the block is either cracked or warped, probably due to excessive heat.
You can only bandaid this kind of problem so long as you have found.
With more water than oil in the crankcase, I would pull the plugs. The cylinder that's blown will have a very white colored plug as the water will clean it up.
That will at least tell you which side it's on and maybe save some time.
My bet is a cracked or warped head.

 

Pull the plugs and do a compression test. You should have done that before replacing the head gaskets. Also like miller said inspect the plugs as they usually give a good indicator on the problem cylinder

 

It is cheaper and easier to just replace the engine at this point. You can have the motor out and the other one starting back in in the time it take to remove the heads. There are good and bad salvage yards in every community use a good one to locate a good engine and do the swap and don't over heat it or freeze it and it will go to about 220 to 250 thousand miles.

 

My 01 5.4 motor in my 98 Expy has been having this leak as well on the right side. Sad to say, darn near since I got it dropped in back in 2011, but no one could pin point where it was coming from nor replicate it. I didn't have the time to really get into it. Now I have a little more time to dig into this. I notice she smokes less or not at all, when allowed to warm-up first before doing any driving; especially on the highway. Has anyone else found this to be true? I have been doing a lot of research and from what I am finding. I am not happy. Good Luck Sprucegreen, let us know how you fair!

 

Could be a cracked block.

 

He posted once a year ago, not so sure he will be back to report to you on this. He might be on the side of the road overheating.

 

You might be surprised. I've said that very thing myself only to have the OP pop in and answer. I guess it all depends on if they are subscribed to the thread or not.