I posted this on the engine forum. This is not a truck, it is my Thunderbird.
Hi all I have 1996 <nobr style="font-weight: normal; font-size: 100%; color: darkgreen;" id="itxt_nobr_0_0">Ford</nobr> with the 4.6 litre engine. On the way home from work while driving at freeway speed I got a low coolant warning. I quickly pulled off of the highway and shut engine off. There was coolant pouring out from the back bottom of the engine. I towed it home and have put it up on ramps to get a closer look. I can see water coming from the area between the transmission and the back of the engine . It does not appear to be coming from the top of the engine. Any ideas?

 

On the early 4.6s there is a coolant tube that runs from the back of the water pump to under the intake. I don't know if your car has one. Those 4.6s are know for the intake cracking, but thats on the cross-over upfront and I would assume you could see it. Check the heater hose connections too. Good luck.

 

Have you had you collant changed recently ? The intake manifold is plastic. At the rear of the manifold there is a hose that needs to be removed from the fitting to burp air out of the system. This fitting is not threaded. It is either molded or press-fit in. When removing the hose, this fitting will either loosen or come out.

I had this problem on my Mustang GT and ended up cleaning carefully, then epoxy the fitting in. It would probably be better to pipe-tap and thread a fitting in.

I went to Ford about this and of course, their solution was a new manifold....

E-Dawie

 

Thank you for the feedback. There is no coolant leak up high on the motor. It is nice and dry. I started it up and the water pours out between the end of the oil pan flange and the trans. bell housing. When it is idling there is a lot of steam out of the tailpipes. Water is dripping out of the mufflers.

 

Check your dipstick for water content in the oil. And/or if there's any coolant left in the radiator or overflow is it oily. With steam coming out the exhaust, and I'm guessing it's not normal, I'm going to guess head gasket. Around here this time of year we get the condensation out the tailpipes on a reg basis.

 

No coolant in the oil, and could not see any oil in the coolant that was coming out of the bottom. I was thinking head gasket also because of the water out the tailpipes, but wondered why it would be leaking at the back of the engine.

 

the early 4.6's are to what i've read prone to popping head gaskets . mine hasn't yet , but i'm waiting for it . you ckecked the coolant lines ? and there is a coolant tube under the intake , and those dain plastic intakes have that beloved fitting eman is talking about too . so you got a whole long list of things to look at . according to those who are in the know my aluminum intake is a pos for performance use , but i dont have any of the issues the rest suffer !!!!!!!!!!!!!!!!!!!

 

I agree with mr4spd coolant pipe under intake or cracked intake manifold.

 

The coolant lines to the heater are not leaking. This car was owned by my Dad since new. I think that he had the intake replaced by Ford under warranty. Would a bad head gasket cause an external leak?

 

I agree wit the others.
I've seen it many times.
The intake cracks and leaks into the valley beneath the intake and runs out the back in the flywheel housing.

 

Thanks all for fielding this question. It is the intake manifold. It ruptured on the bottom and leaked into that valley. When it blew at highway speed it sent coolant all over the place. Now it just runs to the back and drains down between the block and the trans., giving the illusion that it is leaking out of the back of the engine. When I pulled the alternator, I could get a hand up under the manifold and can feel a crack that is about 4" long.
I see were they are selling these manifolds with the coolant passage made out of aluminum and the rest of the manifold out of plastic. Does anybody who has replaced this have a preference as to were to get a replacement?

 

I've always had good luck with dorman brand replacement intakes. They usually re-engineer the part so that it won't repeat. They should carry it at a local autoparts store.