This is a thread about my 4.6L home head gasket replacement. This is a big job, and takes time, but it is handy not to have to pay $2000 to have it done by a professional. Very little of the cost is Parts, as long as nothing else is badly wrong.

I realized I needed head gasket(s) when I noticed bright white smoke from the exhaust. It smelled like burning antifreeze, and there was grey/white crust in the oil and the coolant reservoir. I tried running the gasket seal in a bottle, but I think it didn't work because the water system in the expedition is so large.

I have worked on my own vehicles before, so maybe I wasn't as daunted as I should have been before starting this task.

I wanted to see some pictures like this, but I couldn't find any on the forums, so I decided to put mine out there; I was taking pictures for reassembly help, anyway.

So here's a few pics of the disassembly :




The beginning...

 

Removing the plastic pieces

 

Removed throttle cable bracket along with vacuum lines and electrical connectors

 

Removed upper radiator hose and I can see the alternator needs to come off. Also getting the connectors of the wiring harness loose so that they can be out of the way.

 

Removed the throttle body and associated vacuum connections


See how dirty it is inside the intake!



And inside the throttle body:

 

Continued disassembly...



Fuel rail removed



There used to be an insulation layer on the plenum, but it was totally cooked to a crispy pile. I will have to see if there is a replacement.

Also found a few ounces of oil in the bottom of the plenum. That may account for the sticky black gunk in all the runners and the throttle body.






You can see the clean spot inside the intake port where the injector kept it clean.

 

That sticky black oil in the plenum - you might want to replace your PCV valve - it may be stuck open and flowing too much volume at idle, pulling oil an oil fumes into the intake.

 

You might want to think about replacing that heating tube that runs under the intake. It's prone to leaking and could cause you to have to pull the intake once again.

 

PdqFord: That's as best as I can figure, as well. can they be cleaned, or do they need replacing?

Alloro: good suggestion! I haven't looked at how it is attached yet. Do I need to remove the water pump?

Good to know you're looking at this. Thanks for your posts!

 

Digging deeper into the engine. One possible problem: I took pictures of the alignment of the timing chains and gears, but when my kid got ahold of my phone, he must have deleted a few of them. Well, I'll share what I have got.



Now for head removal. Up until now, this has been a pretty straightforward job. Find the bolts and turn them counterclockwise to remove. This approach only works when you can see/touch/get-a-wrench-on the bolts.
In order to remove the heads, the exhaust manifolds have to turn loose on one end or the other. On the head-end, I could only see two out of eight bolts, and I couldn't get to the ones on the underside of the manifolds. So instead, I took the other end loose from the y-pipe. only 2 nuts per side, and I can see all of them from under the truck. Now, being on the exhaust, they were stuck-on somethin' fierce! Using all of my man-strength and some W-D, I managed to get 3 off. The only one I couldn't get was on the top side of the passenger manifold. Everything is in the way! With my extensions and u-joint, it would just bind instead of applying force on the nut. I even removed the wheel and fender liner, but I still couldn't get the sucker loose.
I decided that I would like to do headers if possible, justifying the destruction of the offending fastener. I used about 6 blades with my reciprocating saw before chucking up a tiny cutting wheel in my dremel, and even then I had to break the last 1/16" loose with my beatin' screwdriver. Free at last!



Yuck. Is this really the same engine that was running when I parked it for this job? There's a thick layer of burnt-on oil (???) or something. And the chambers in the heads are just as bad.

And I hope you can see this: deep grooves in the cam races and on the cam itself.






I have already shared these pictures over on the mod motors forum, and one reply so far says that I probably need new cams. The races just have a chewed look, as if sand went through the cam oilers. I'll get more pictures tomorrow, but I can see tracks leading away from the oiler orifice under the cam. How much can a machine shop do for me here? Are my heads ruined?
Well, now I need to decide what to do to fix this. I think everything I do from here on out will be cleanup, purchase of parts, and reassembly. More to come. In the meantime, I appreciate your input!

 

Well, if I was doing all this and had the heads out of the truck, as well as taking off the cams I would probably just go for rebuilding the heads with new parts and all.

 

Like valves and springs, too? Or just what looks to be the affected area?

 

I would do valves, springs, lifters, seals, everything, so you in effect get a re-manufactured head. The expense isn't too bad for those. Also check for warping, and perhaps consider taking it to a machine shop to resurface the mating surface and all. It's not too expensive, but it depends on your budget.

 

Check eBay for the heads, some guys on there have good deals for already reconditioned ones.

 

New reman heads on rockauto is about 560 bucks pr head with a $125 core, so if you send your heads back you're looking at 870 bucks plus the shipping costs. That could be an option.