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Where did you guys get all this info and does it also cover Expeditions of any year? I am starting to get misfires in the #5 #3 and #7 on the old lady's Expy so I pulled some plugs and #5 and #7 had coolant on the threads. I did not even mess with #7 as it is darn near up under the firewall. Is this some of the same symptoms you guys are having? I have had no problems at all with the 96 'Stang on this.


It is a 4.6 by the way, the Expedition that is.

Jglisson

That isn't good. If you have coolant on # 7 then you have a head gasket gone. Sell that bitch now.

GT Tommy

My son has a 2003 GT Mustang with a 4.6L engine. There is a coolant leak between the base of the aluminum thermostat housing, and the black plastic portion of the intake manifold. If I only knew how to post a picture here, I would. Can anyone help me with that? Being that this is a 2003 model, the aluminum cross over has already been installed by the factory. It appears to me, that the design of the new aluminum cross over did not resolve the coolant leak problems. I have seen case after case where the leaks are almost always between the base of the aluminum thermostat housing, and the plastic portion of the intake manifold. My question is, can this aluminum cross over be removed witout removing the intake manifold? Has anyone physically removed it without removing the intake manifold? If this is possible, then all I have to do is to remove the aluminum cross over section, and install new gasket material between it and the black plastic portion of the intake manifold. As of right now, without actually separating the aluminum cross over section from the black plastic intake manifold, it is difficult to determine if there is a crack in plastic manifold itself, or if the gasket is the culprit. However, just by watching the coolant leak, it does appear to be leaking between the gasket and the base of the thermostat housing. Any support will be greatly appreciated.

BlackMage

if its leaking right below the therostat housing with the aluminum crossover, it did the same thing mine did. it warped and cracked, and leaked antifreeze everywhere

1999 GT

ok guys, ALL 99-04 mustang gt's have "plastic" intake manifolds, however, 99- april of 01 had the plastic crossover. in april of 01, ford corrected the "cracking intake" issue by using an aluminum crossover.

GT Tommy

Hi BlackMage, that is an awesome picture. That is the exact same spot where I see the coolant leaking from. That's why I mentioned previously that, even with the new aluminum cross over section installed, there is still some kind of a design flaw present. From looking at your picture, it appears that the aluminum cross over is able to unbolt from the intake manifold while it is still installed. Is this possible, or not? For this one area I know there are the two long bolts that bolt from the top, and it appears there are 3 short small bolts that bolt from the bottom. I would imagine it's these 3 short bolts that are difficult or impossible to remove with the intake manifold still installed, am I correct on assuming this? Thank you for the picture and your outstanding support. It really is a big help in understanding what is going on here.

BlackMage

well there are three bolts on the bottom of the intake manifold, let me rephrase that, three bolts on each side of the crossover, so a total of six bolts that you will have to take off from underneath. i do not think it is possible to take off the crossover pipe without pulling the manifold. sorry man

GT Tommy

BlackMage, if I had to bet on it, I would say that the major contributing factor in the design flaw for the coolant leaks in this immediate area is with the use of the "0" ring. I can't see why they did not design and use a flat gasket in this area. "0" rings require alot of compression to keep the coolant from leaking. With that said, the thickness of the plastic flange that the thermostat housing bolts to, is not thick enough to with stand the required torque to keep the coolant from leaking. While tightening the bolts, if anyone of them have to much tension on them, it's easy to see why the plastic flange area will crack and form a leak. Can you tell me if the other end of the cross over section (on the passenger side) is designed with an "0" ring as well? How many cracks did you actually find on the plastic flange area? I see one at the top left port hole. Were there other cracks anywhere on that flanged area? Thank you for your support.

BlackMage

yea its the same on both sides, O-rings. the only crack i found was where its circled, you can see where it almost like melted and pushed away from the o-ring. and btw, ford does not carry those o-rings. i searched everywhere and could not find them. i think dorman might have them, but i cant remember, that was like 2 years ago i was lookin for em

GT Tommy

Did you purchase and use the same type of intake for your repairs?