Head vs Intake 2003 Expedition 5.4
 

Forum Newbie: I am getting ready to dig into the top end of my wife's 03 Expedition and I want to avoid doing the heads if I can. How can I be sure it's NOT THE HEADS?
1. Runs perfectly. Purrs like a kitten, no codes. Good power.
2. Blew coolant out of the overflow twice. Cap replaced both times. The temp sensor would spike for only a few seconds, it would blow out the cap and the temp went right back to normal and it would run fine until it completely cooled. Seemed like an air bubble, probably at the now leaking crossover.
3. I can see a leak on the passenger side of the crossover that is leaking into the plugs and into the valley. The heater hose in the valley looks OK. The firewall heater hose connections look pretty good, but there could be some water staining on the firewall, hard to see.
4. ***** Coolant leak above starter/passenger exhaust manifold area. Can't see where it's coming from even with an endoscope camera.
5. Oil is clear. Coolant is clear and no bubbles when running. I did the chemical test on the overflow tank and it came back non-conclusive. Color turned neutral, but something caused it to blow back through the cap.
6. I am losing some coolant and some oil. For the oil, she has 204,000 miles, so it could just be blow by burning and not a new symptom.
7. Exhaust has some white smoke on our cold mountain mornings, but it goes away fast and no sweet smell. Only some water condensation, no coolant.
Bottom line: no direct oil or coolant head symptoms. I was thinking of using an old pressure cap and attaching a hose fitting and pressurizing the system to try to find the leaks. I would really appreciate any help sorting HEAD vs INTAKE! Thanks in advance!
Greg in Flagstaff

A known issue is cracking on the intake if it has the plastic intake. It cracks around the aluminum crossover where you indicate you have a leak. This requires you to replace the entire intake, though the new ones from Ford are supposed to be improved.

As for pressure in the system, not sure what this comes from. If it doesn't have any other signs of head gasket issues, I would start by fixing the known issue, which is the leak around the crossover.

Thanks Skauber! That's good advice. Fix what's broken! Plus when I get the intake off, I can see all those back heater hoses. Thanks again! g

Agree with this statement. My '01 started leaking there...slowly at first. Then one day the whole thing went and water sprayed everywhere. Replaced with Dorman aftermarket intake (plastic design). Now 100k miles and still going strong.