coolant leaking between aluminum crossover and intake

Merry Christmas?

Did you crack it during the build?

Thats good. Can't wait till you get her tunned. I wanna know how it runs

98COBRA281 said:

oh yeah, i have gave it a little and it feels realy strong!!, and get stronger as the rpms climb im realy hoping to put down 280+, and i think it will

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if it done make 300rwhp get new cams........see sig

mine was leaking under the thermostat housing where the aluminum meets the plastic. i went to buy a gasket from ford, they told me it was most likely cracked since it was all one peice. i took it in for the powertrain warranty and sure enough it was cracked. they replaced it for free. mines an '03 btw.

98COBRA281 said:

yeah, i have heard GREAT things about hitech stage 2 cams, some say there the best N/A cams..........

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they are check out the website Hitech Motorsport - Performance EFI Tuning / EFI Dyno Tuning Experts - Elk River, Minnesota - Midwest Region no loss in low end torque and 300rwhp with stock long block. hope yours does well though

Thermostat Housing not quite right

I have a '01 and the Stock Intake broke at the heater hose fitting. I replaced the Intake with a Ford Racing Products Intake I got from Summit. Everything went in fine except the Thermostat Housing. The origanal Intake had bushings and the Thermostat housing had large holes that go over the bushings. The new Ford racing Product Intake has the Aluminum crossover and does not have the bushings around the bolt holes, so the thermostat housing is loose and does not seal. Where do you buy a replacement thermostat housing to work with the new Intake.

Thanks

Intake Coolant Leak!

98COBRA281 said:

well i just relized that i will have to take the whole intake off

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Yes, to repair your leak properly, the intake manifold has to be removed. My son's 2003 GT Mustang had an intake leak (shown below) in the same location as yours. We removed the intake manifold and found what you see in the pictures below. The top picture is the bottom view of the intake manifold just below the thermostat housing base and the intake manifold. The lower picture is again the bottom view of the intake manifold on the passenger side, just below where the aluminum cross over channel bolts to. I have seen numerous complaints on all of the Ford Forums concerning coolant leaks in these area's of the intake manifold. I believe that there is a design flaw with these intake manifolds which always ends up with coolant leaks. My personal opinion to what is contributing to these coolant leaks, is a faulty or stuck thermostat. The thermostat get's stuck in the closed position. The coolant has no where to go with your water pump pumping, so, the coolant looks for the weakest link in the system to escape. I believe the weakest link are these two area's shown in the two pictures that I have provided. The O ring seals in these two area's gets forced out of place with the coolant pressure, which then causes a coolant leak in these area's. We ended up replacing the intake manifold with one with the latest design revisions. Hope this helps! Good luck, Tommy.

Mine did the same as pictured above. This would be my 3rd junky plastic 2V intake between 2 cars. Just a crap Ford design IMO which adds to the list of design flaws I've dealt with on the 4.6L. If it's not intake coolant leaks it's spark plugs blowing out of the head, chain tensioners failing, oil pump gears failing, among other things. I guess the only answer for me is to either replace parts until there are little to no Ford parts left on the motor or cut my losses and get back into a pushrod motor. I think the only thing Ford got right on this motor is the block casting.

GT Mustang Coolant Leak Culprit!

NitroFishGT said:

Mine did the same as pictured above. This would be my 3rd junky plastic 2V intake between 2 cars. Just a crap Ford design IMO which adds to the list of design flaws I've dealt with on the 4.6L. If it's not intake coolant leaks it's spark plugs blowing out of the head, chain tensioners failing, oil pump gears failing, among other things. I guess the only answer for me is to either replace parts until there are little to no Ford parts left on the motor or cut my losses and get back into a pushrod motor. I think the only thing Ford got right on this motor is the block casting.

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If you haven't already tried it, you may want to run a 180 degree thermostat. This is what we are using after we replaced the intake manifold, and so far, no coolant leaks or heating problems. To me the stock thermostat is far too hot for the designed flawed intake coolant port area's, where the O rings are being forced out of position, as shown in my two pictures posted in my previous thread. I strongly believe that a stock defective thermostat, is the culprit for most, if not all of the intake coolant leaks, concerning the plastic 4.6 intake manifold. This is just my opinion, however, if you think about it, it makes sense. One important NOTE: If you see the coolant level in your reservoir dropping, and you have to keep filling it up, this should be a "RED FLAG" to you. You better start looking for a coolant leak. Check your engine oil to see if coolant is getting mixed with it, and check all the area's around your intake for coolant leaks. If your cooling system is working properly, your reservoir should maintain the proper coolant level for a long time. You shouldn't have to keep topping off your coolant reservoir. Hope this helps. Good luck, Tommy.

Intake coolant leak!

98COBRA281 said:

old thread but....

i took it off, cleaned it up, used black RTV, let it sit overnight, and its ben perfect ever since

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Awesome! If it acts up again, you will know what to look for. Good luck, Tommy.

I'm a new, old guy, to this forum and I've experienced coolant loss with this 4.6l 2v engine in a 2003 Grand Marquis.
A while back, while driving, I detected the odor of antifreeze. Ah, couldn't be me, maybe it's the guy in front. This continued for a while until the time came when my temperature gauge started indicating a low temperature. This was considered the fault of the thermostat. I bought a new one and took the mounting apart. When I took the thermostat out I noticed 2 little chunks of plastic resting at the bottom of the housing. What are they, and where did these come from? I tossed them in the trash. I also noticed there was a bulge in a flat 'O' ring protruding into the housing area. I tried pushing it back in, but no success. I left it as such.
I flushed out the system and put in a cleaner, ran the car for the suggested time and then drained the system. I opened the thermostat housing, and when I removed the thermostat, I saw ANOTHER small piece of plastic chunk. This is the third one. Where in the hell are they coming from?
After having a new replacement manifold and coolant crossover installed, I decided to investigate the old manifold.
Removing the crossover from the manifold I found where those pieces of plastic were coming from.
There are 2 channels designed into the manifold that accepts a flat 'O' ring to seal.
The inner wall of this channel is very thin.
The stresses of the heat from the engine, the cold of the natural elements and the basic vibration stresses on the engine itself, and/or improperly torquing of the mounting screws, over time, caused this inner wall of the channel to fail and break off into little pieces, thereby allowing the gasket or 'O' ring to squeeze out and into the passage of the coolant, allowing a leak.
This failure happened on both sides of the crossover. There is no repair to this plastic channel of the manifold that will withstand the rigors of the what the engine goes through.
There are no replacement gaskets for this unless you buy a complete, new replacement manifold, and because the inner wall of the channel was broken, the new gasket would be useless anyway.
I'm guessing these small chunks of plastic, or a single one, got stuck in the thermostat, somehow holding it open.
With the new manifold and crossover on the engine, my temperature gauge now indicates proper operating temperature, and there are no more leaks.
So for this tiny, little, teenzy weenzy leak, the entire top of the engine had to be removed and the manifold replaced causing the loss of a weeks pay.
Fords 'better idea' sometimes suck.