Coolant spewing out of rubber "plug" on top of engine.

[Jim_WY]

2002 V8 (5 liter) Explorer.

I've got a serious coolant leak/dump onto the top of the engine of this 2002 explorer.

The coolant is coming from some sort of opening on the top of the engine, back near the firewall. This seems to be an unused hose connection or some sort of freeze plug, or whatever.

I do not know what the factory "plug" is supposed to be for this opening, but at the moment, it has a rubber boot of some sort over it, held in place with a hose clamp. The boot has failed, and has large cracks in it, so that's where the leak is.

This boot was installed by someone else, so I don't know if it's the correct part for the job or not.

It seems like the hose clamp that holds it in place may be part of the problem, having squeezed the rubber boot down and virtually cut it, or at least weakened it so that it failed.

I'd like to know if there is a proper replacement boot made for this, and if so, what is it called, so I can ask for it at the parts store.

I could probably make something out of a piece of correctly-sized hose with a plug at one end, and the other end clamped over this fitting. But I can't help thinking that there's a good, cheap replacement part made just for this.

If anyone knows what the part might be called, that'd be a good help.

I have a photo of this thing while it was spewing out the water I'd just poured into the overflow tank. But you can't see it well because it's hidden behind an injector rail or something.

If this was a leaking water tank, I'd just whittle a hardwood stick down to a proper-sized tapered plug and pound it in with a hammer. But something makes me think there's a part someone would like to sell me that will work better.

If anyone has any ideas about what this part is, or what it's called, I'd love to get one.

Thanks, everyone.

 

[rocco123]

Looks like an aftermarket intake that has the intake manufacturers cap on it. I doubt the whittled down stick will work. Remove the cap and Head to autozone or what ever parts store is close by and get a cap (may be in HELP parts section). install using a worm gear type clamp, refill antifreeze your done. Your post with all the pics probably took longer that it will take to fix it.

 

[lincolnshibuya]

I used those Help! rubber hose caps from advance auto then bought those worm gears with colored flat plastic heads that can be tightened by hand and removed after.

 

[rocco123]

Read enough about these failing so I just bought dorman 02253 pack of caps. will keep in truck just in case

 

[Jim_WY]

Thanks, everyone.

The intake was replaced by our mechanic a while back. This leaking boot is held in place by a worm gear hose clamp. It's only been in service for a few months. Hopefully an aftermarket plug for the aftermarket intake manifold will last longer!

I like the idea of keeping a pack of them in the car at all times. Maybe I can jury rig something more permanent. If the boot was reinforced like a hose, it might be more long-lasting. I'll see what I can find.

 

[Number4]

This piece is an issue on the aftermarket intakes. Should find comments in the forum about it and how to best fix it. Someone here already went through and documented it.

 

[rocco123]

Can u let is know I'd it's 5/8 or 3/4. A section of heater hose with a bolt clamped in would probably be even better.

 

[Bobmbx]

What is this "Cap" a cap for? A vent for filling the cooling system?

Consider this as a permanent fix

 

[dieselscout80]

What is this "Cap" a cap for? A vent for filling the cooling system?

Consider this as a permanent fix

Not likely for a plastic intake.

 

[Jim_WY]

I used those Help! rubber hose caps from advance auto then bought those worm gears with colored flat plastic heads that can be tightened by hand and removed after.

I need to look specifically for some of those. Had no luck finding them at the store I went to this afternoon, but they sound like a good way to go.

Read enough about these failing so I just bought dorman 02253 pack of caps. will keep in truck just in case

Looked for those, too, and the store didn't have that particular pack, either.

This piece is an issue on the aftermarket intakes. Should find comments in the forum about it and how to best fix it. Someone here already went through and documented it.

I did do a bit of searching on here before starting the thread, and couldn't find any threads with this exact cause of the leak. Found lots of them about the head gasket leaking (what I had originally), and more about the thermostat housing leaking as well. Then there was one where I think the OP had my exact problem, but it was never answered in that thread.

So I decided to resurrect the issue.

Can u let is know I'd it's 5/8 or 3/4. A section of heater hose with a bolt clamped in would probably be even better.

It's got to be 5/8". That's the ID of the boot I took off. I looked at the parts store, and they had 1/2" and 3/4" heater hose. They gave me a small chunk of the 3/4" stuff. I wasn't sure I could get the 1/2" to fit over the fitting, and I don't want to put too much force on the intake.

Edit to add: Upon closer inspection, I find that 3/4" heater hose fits very nicely. 5/8" would be too tight, or not go on at all.

What is this "Cap" a cap for? A vent for filling the cooling system?

Consider this as a permanent fix

I think it's just a place where a hose could go in some other configuration. It's really a hose fitting, but isn't used in the setup on this vehicle, so it has to be plugged off.

Not likely for a plastic intake.

Don't laugh too hard. I seriously considered getting a copper end cap from the plumbing department of a hardware store and soldering it over that unused hose fitting. It's steel. But alas, the rest of the manifold is plastic, so I kind of thought better of that idea, too.

Edit to add: Upon closer inspection in daylight, even the nipple is plastic! Soldering would have been a very very bad idea.

Here's the failed part that I took off today:

Here's what I found at the one store I've visited. I may try to get to some other parts stores to see if they've got something better:

At first, I picked up those "Baitwell Plugs" as kind of a joke, but the guy at the parts store said he thought they might actually work quite well.

Edit to add: Turns out they're ever so slightly too large to fit inside of the plastic nipple. They'll go in until they hit the lip that you can see in one of my later posts, and that's it. So that was a bad idea, too.

I guess as long as they can stand the temperatures, and as long as they don't rust apart and drop pieces down into the manifold, they might actually be a viable answer.

Still, I'd feel better about using a piece of heater hose, a stainless bolt, and two hose clamps!

 

[Number4]

You may want to pull your coils and use compressed air to get the antifreeze out of the spark plug wells. Otherwise it's been known to short out the plug if too much liquid is in there.

I usually find the threads when looking for something other than current issues.

 

[Jim_WY]

You may want to pull your coils and use compressed air to get the antifreeze out of the spark plug wells. Otherwise it's been known to short out the plug if too much liquid is in there.

I usually find the threads when looking for something other than current issues.

That's a very good point and a good idea!

Yep. The symptom that tipped us off to the leaking intake manifold in the first place was the engine "missing" due to one of the plugs being shorted out by the coolant pooling up in one of the wells. That leak was not enough to have caused cooling problems yet, but it still needed to be fixed.

In this case, that rubber boot failing all at once caused the coolant to dump rapidly. I hope the engine wasn't damaged because things got pretty hot before I could safely pull off out of traffic! It'd be ironic if the failure of a silly rubber plug trashed the whole engine as a result of it being a poorly made part - part of that newly-replaced intake manifold. That would be the end for this truck. It's somewhat in need of a new transmission, just had the intake manifold replaced, and now, perhaps the engine will be shot.

I think I'll hose the whole top of the engine off to get rid of most of the coolant residue, then, as you suggest, blow things out really well with compressed air to help things dry out!

I like the search function on this site. But just couldn't find anything talking about this particular boot thingamajigger.

And you're right, I often stumble across golden nuggets of info when looking for something completely unrelated!

This is an excellent forum, indeed!

 

[swshawaii]

The rubber bypass cap failing on replacement Dorman intakes is VERY common, even on other forums. Easiest solution I've read is using a short length of reinforced heater hose and a bolt with hose clamps mentioned in post #7 . Good luck, hope your engine is OK.

http://www.explorerforum.com/forums/showthread.php?p=3389319

http://www.explorerforum.com/forums/showthread.php?t=393778

 

[Jim_WY]

Bingo! So it's called the intake manifold "Bypass Cap". That's the answer to my first question, I guess.

Thanks! I read those threads, and posted to one.

I got the 3/4" hose (in the photo above) but just need to get a stainless 3/4" bolt, and I'll be ready to use the heater hose fix. That does seem like about the stoutest way to seal that bypass connection given that the manufacturer-provided part is not up to the task.

 

[Number4]

NAPA carries 5/8 heater hose if that's the actual size needed.

I'd also apply some Indian Head Shellac to the nipple before putting the hose on.

 

[lincolnshibuya]

When I installed the Dorman intake manifold it has 2 aluminum plugs supplied, I put one of the plug in the hole snugly (there's no thread) It leaked later and I decided to put in some extra stuff to tighten it, that's where I use the rubber caps and the worm gear clamp. I do believe that if there's no aluminum plug on that hole, overtightening the worm gear clamp can crack the plastic.

 

[Jim_WY]

When I installed the Dorman intake manifold it has 2 aluminum plugs supplied, I put one of the plug in the hole snugly (there's no thread) It leaked later and I decided to put in some extra stuff to tighten it, that's where I use the rubber caps and the worm gear clamp. I do believe that if there's no aluminum plug on that hole, overtightening the worm gear clamp can crack the plastic.

Upon examining the hose fitting on this bypass, it is, indeed, made of plastic. So that makes me wary of even putting a heater hose and hose clamp on it for fear of crushing the plastic fitting.

I'd feel a lot better about it if I had a metal plug to put into the fitting before pushing the hose over it and cranking things down with a worm gear hose clamp.

I wonder if that metal plug is available anywhere.

Here's the fitting on my intake manifold. Looks kind of flimsy now that I get a good look at it in daylight. I'd hate to snap it off!

 

[lincolnshibuya]

this is what it looks like http://www.autozone.com/1/products/...odized-aluminum-pipe-plug-mr-gasket-6352.html

not sure if it's 3/8 or 1/2

 

[Jim_WY]

this is what it looks like http://www.autozone.com/1/products/...odized-aluminum-pipe-plug-mr-gasket-6352.html

not sure if it's 3/8 or 1/2

Thanks for that! I do think you're right about the aluminum plug being handy to support the plastic nipple so it won't crush when you tighten a hose clamp over it.

It's interesting that Dorman wants you to just screw a threaded plug into a non-threaded hole. I'll have to get some calipers and see what the ID of the plastic nipple is if I want to find a plug that will sort of thread into it.

Does the manifold come with any of the boots, too, or do they figure the threaded plug will seat against that lip in the nipple and make a seal that way, and that's all you'll need?

It all sounds kind of dodgy.

When you use a compression fitting with plastic tubing, you often use a brass insert into the end of the plastic tube to provide support for the tubing so that when the ferrule crimps down on it, it won't crush or deform the plastic tubing.

I wonder if something like that might be good in this application, too. Something that fits deep into the plastic nipple to support it right where the hose clamp will be, so that it won't be crushed when you tighten the worm gear hose clamp.

I guess I might try it, but just be very gentle and hope it doesn't blow off of there.

OK. I looked up the manifold on Dorman's site. The installation instructions don't say anything about this port.

So I've emailed them to find out if there's a particular part they have or way they suggest to seal off this annoying geyser of coolant!

Anyhow, thank you, and everyone, for your thoughts on this.

 

[Jim_WY]

NAPA carries 5/8 heater hose if that's the actual size needed.

I'd also apply some Indian Head Shellac to the nipple before putting the hose on.

It turns out that 3/4" hose fits the nipple quite well. And I'm not sure I'd want to use the shellac on the plastic. If it was a steel fitting, as I was sure it was in one of my posts above, it'd probably be just the stuff. But I'd worry about any solvent in it potentially attacking the plastic.

But, again, thanks for the suggestions. I really do appreciate all of the help I've received here.


I put together a plug from some 3/4" hose and a steel (not stainless, couldn't find one) 3/4" bolt. I've got it in place, and I'll try it out just to see if the engine will start and run now. I'll still let you all know if Dorman responds to my email asking them what their official recommendation is for fixing this.

Thanks, all.