2004 Limited w/ 4.6 Coolant Leak on backside of engine

[pet575]

Guys, I've got a leak somewhere on the backside (firewall side, passenger side) of my engine. I'm having trouble running it down but I'm having a ton of coolant sprayed on the firewall and it is burning on the engine back there somewhere on the passenger side.

I suspect it is a heater hose but I have ZERO experience with the heater hoses on this model. All I can easily see are the AC coolant lines running in there through the firewall.

Can anyone help me with exactly where to look for this leak? I'm losing 1 gallon of coolant everytime I drive somewhere and we are in the middle of wintry conditions here so I've got to get this thing repaired ASAP (not to mention that $10/gallon of antifreeze will bankrupt me soon LOL!).

Thanks!

 

[pet575]

My Googling skills lead me to believe it could be the heater hose that runs underneath the intake manifold. Anyone got any experience with that? Don't really feel like pulling the intake manifold off for that project if I can bypass that situation.

 

[lincolnshibuya]

You are on the right spot (it's actually above the intake manifold and you don't need to take out the intake manifold), I used hose caps tightened with clamps to secure that heater hose outlet. Got those from Advance auto as a set.

 

[pet575]

So did you bypass it with a different hose?

 

[lincolnshibuya]

no, I just plugged it because the aluminum plug supplied is not tight enough (it leaks) I believe on the mountaineer with automatic climate control there's no hose going into the heater but the dorman intake manifold has it.

 

[pet575]

Check out 2nd and 3rd pics in this thread:

http://www.explorerforum.com/forums/showthread.php?t=361187

Looks to me like that heater hose is under the intake. Am I looking at this wrong? Or is it accessible on the backside to where I should be able to fix it from there?

Confused on how/where you used the hose caps.

 

[lincolnshibuya]

here's the pic, it's almost identical and take a look at the circled item near the firewall.

http://www.agcoauto.com/content/news/p2_articleid/185

 

[pet575]

Tore into this last night. Removed the heater hose and found no damage to it, leak tested it and found nothing. Replaced hose clamps and put it back together. Still leaking.

Verified the steel (or whatever type of metal it is) tubing is running from the back of the water pump and across the top of the block and under the intake manifold. If I attempt to bypass it I'm going to have to cut it loose from the back of the water pump. Not sure if I can fit the necessary tools in there to do that without manifold removal.

Thinking I'm probably going to have to remove the manifold unless one of you guys out there has done the bypass and knows whether the cutting is possible?

 

[lincolnshibuya]

you might look into this if you don't want to remove the intake manifold.

https://www.youtube.com/watch?v=DPTPL6lVuFM

 

[pet575]

Thanks I did run across that video right after I posted my OP. I'm strongly considering this route. The question I have is how to remove that metal tube and what type of metal it is made of. I'm guessing I'd have to cut it and I'm not sure if I have the tools to do it. I have a Dremel with some metal-cutting bits so that might work. Not sure if I can fit it in the space after alternator removal but that is going to be my first plan of attack.

I'm also starting to question if I have a blown head gasket so I'm going to drain the oil and see what it looks like while I'm doing all of this. Hopefully I'll get some quick resolution to these questions.

The cold temps in KC are making it more difficult. If it were summertime I'd keep refilling with water as I work through it but I'm losing a gallon of coolant each time I drive it. Already spend $30 on coolant just figuring out WTF was happening and being in a bad spot with being forced to drive it to work each day.

Luckily my in-laws have lent me their car for a few days to where I can park it and work on it as time allows.

 

[silverfox103]

Don't know if this applies to your situation but the last two 4.6 cars that I've had, 1998 CV and a 2003 GM, both had the "plastic" intake manifold that had to be replaced. This is a very common problem with these engines. If I remember correctly both leaked towards the back of the engine.

Tom

 

[pet575]

Replaced the intake previously. I don't believe the leak is coming from there but I wouldn't be shocked by it either. Replacement intake has fewer than 75K miles on it, though.

 

[pet575]

Pulled the intake manifold off yesterday to get to this metal coolant tube. No apparent holes, slits, etc. in it but it looks like there is a lot of corrosion on it underneath the paint. Going to Ford dealer today to find out how much they want for this stupid piece of metal. If it is overly expensive I'm likely going to manufacture one of my own using heater hose with heat shield surrounding it. Should cost a lot less to go that route if I must.

Will update and probably end up turning it into a new how to thread with a few pics.

 

[pet575]

Ford dealer couldn't easily identify the part and would have to special order the "suspected part" for me. This would include paying in advance and waiting 3-5 business days, neither of which I'm willing to do.

So, I'll be manufacturing one of these out of heater hose and high-temp plastic elbows. I'll take pics and put together the info once I'm done. Hopefully this fixes it so I'm not turning to a cracked block/blown head gasket scenario.

 

[pet575]

Well I replaced the top coolant line with heater hose and elbows and got everything put back together..........and it appears that the leak got WORSE. It is coming from what looks like the backside and passenger side of the engine, somewhere near the firewall that I just can't see.

I guess I'm at the point where I have to determine whether I have a blown head gasket or a cracked block. I guess the other possibility is that the intake manifold somehow is leaking but I can't see it.

Pretty frustrated right now. Anyone have any thoughts/ideas on how to check for a cracked block in an area I really can't see into? I'm going to drain the oil and see what it looks like in the meantime.

 

[pet575]

Did some poking around today and found some info that I could have a freeze plug problem on my hands. Good stuff.

 

[Weekend]

looks like I a seeing a similar leak... And I too have recently replaced the intake, so I do not think that is the problem. Will be looking into it this weekend, anxious to see if you have any success!

 

[pet575]

I think I found my leak over the weekend. The coolant "cap" that goes on top of the manifold (on the firewall, passenger side of the intake) is leaking. I don't know how I didn't see it before but it is pissing coolant RIGHT into the area I've been finding it. I removed the intake to repair the top heater hose that runs out of the back of the water pump across the top of the block and when I got everything together it was WORSE than before. I think I might have jostled this cap around a bit to make it worse.

The cap is made of rubber and is clamped onto the intake. I'm going to repair it tonight and see if that solves it. Will report back but I'm confidently crossing my fingers.

 

[pet575]

Well I got the leak solved with the "cap" replacement.

 

[Weekend]

This confirms a second case of the leaky bypass cap. Thanks so much for sharing your experiences here, you saved me a bunch of time troubleshooting.

Now the bigger question -- is this cap leak something that everyone who replaced their intake manifolds with the dorman model (to cure the front leak) are going to experience in a couple / few years? In my case I think I recall it's been about 3 years since replacing the intake.

For me there was a muli-pack of bypass caps at autozone for $5.