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Leaking coolant from heater hose

Atreus21

Buick Newbie
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Hi fellas,

02 Buick Rendezvous

I put the whole car back together after replacing the thermostat housing, thermostat, and radiator, only to discover I had misdiagnosed the problem. Coolant is leaking not from the thermostat housing, but the metal tube in the lower intake directly above it. I know it connects to a heater hose, but I'm not sure exactly what it's called.

You can see it in this video, at the 31:07 mark.


Screenshot is here:

1576451802357.png

It's leaking from the connection to the thermostat housing, circled in blue above, so the question is: would mashing a ton of permatex in there suffice? Unlike the picture above, getting to that pipe in my car would require a ton of work.

Here's a closer picture from the actual car:

1576452286576.png


Would welcome any opinions.

Thanks.
 

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2007LucerneCXL

Full Member
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2007 Lucerne CXL. and 1995 Lesabre currently, past 1973 Riviera, 1968 Riviera
If you are at the point where the part is not coming out and looking to bandaid it, probably the Permatex Form-A-Gasket No. 1 Sealant may be a option. I've used on some vehicles before the RTV was available and it held up on my high school beaters.

You need to clean the area really well, pack it in around the leaking area, cut a heater hose down the middle that will fit over the size of the tube about 1" long, push it against the end thats leaking, use a wide hose clamp to hold it all together. Can't guarantee it's a long term fix, but may get you by for awhile.
 
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TollKeeper

Active member
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Brighton, CO
Buick Ownership
2004 GMC Envoy XUV, 2001 Pontiac Aztek
If I am remembering correctly. Its just an o-ring held holding the coolant in, or its a flared end. Removing the 1 bolt on that holds the tube on the head, and taking out the hard pipe, and replacing the O-Ring, or the assembly is the only real fix for it all.

This is the back housing..
Back Housing

And I am still looking for that hose.

Edit: I --THINK-- This is it..

Ebay OEM Style Link
Ebay Dorman Replacement (3x the price)
 
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Atreus21

Buick Newbie
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Buick
If I am remembering correctly. Its just an o-ring held holding the coolant in, or its a flared end. Removing the 1 bolt on that holds the tube on the head, and taking out the hard pipe, and replacing the O-Ring, or the assembly is the only real fix for it all.

This is the back housing..
Back Housing

And I am still looking for that hose.

Edit: I --THINK-- This is it..

Ebay OEM Style Link
Ebay Dorman Replacement (3x the price)

Yes, you're right. The trouble is getting to it. That whole area is snarled with so much traffic. Understand I had just spent 2 days trying to reinstall the damned radiator (after ruining the first new one) and was at the end of my rope when I realized I had missed the actual coolant leak, mistaking it as coming from the thermostat housing. That's why I was so looking forward to a quick fix with permatex.

I wound up having to take the intake plenum off so as to get the EGR out of the way. That meant first removing dogbone motor mounts and ratcheting the engine forward, then removing the throttle body, all the stuff on top of it, the alternator, and then the bracket holding the coil packs. Once that was done it was pretty easy. No amount of permatex ever made would've sealed that leak. The nut holding it in place against that black bolt coming out of the head was missing, and the whole thing was essentially flapping in the breeze. I also noted that one of my heater hoses had snapped off, the one coming off that long bypass pipe from the water pump, and also that the other heater hose was looking in bad shape as well. As it happens that missing nut is the same thread as the nut which holds the wire on the alternator, so I'll just match it up at Autozone and get a new nut.

Another 6 hours or so and I could've probably just replaced the head gaskets (again).

So by the end of this whole nearly two-week-long project I will've replaced the radiator, thermostat housing, thermostat, heater hose inlet tube (the metal one), and both flexible heater hoses.

If that doesn't fix my overheating problem, it's time to consign the thing to the junk yard and start walking to work.

I do have one tidbit of advice: The heater hoses, when connected to the nipples coming out of the firewall, can be somewhat (ironically) frozen in place if they're old enough. After backing the clamp off, I grabbed one with two hands and pulled in a twisting motion with every muscle cord I have, and they moved not one millimeter. The solution: If you have the room (which you easily will if you removed the stuff I mentioned above), get a vice grips, and clamp on to the connection at 90 degrees, but not so firmly as to risk deforming the nipples. Then twist it to rotate the hose about the nipple. That breaks it free and it comes off easy after that.

I appreciate the input fellas.
______________________________
 
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Atreus21

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Buick
Addendum: Found out something interesting. I realize now why the first inlet tube was sealed in place with permatex. Look at this picture of the ends which are supposed to go in the thermostat housing.

1576649921782.png

You can put a finger in the thermostat housing and feel the rest of the tube. Some jackass must've snapped it off and, rather than extract it, just cut one to length then mashed permatex all around it (which I must sheepishly admit was my first idea for fixing this too).

So then, the question is how to get it out. A hook tool maybe? I couldn't get a grip on it with my needle-nose.
 

TollKeeper

Active member
370
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Brighton, CO
Buick Ownership
2004 GMC Envoy XUV, 2001 Pontiac Aztek
I gave you the link to replace that housing above. DONT USE THAT LINK. It appears that one is for a completely different car and engine. The rear of the thermostat housing on this engine is actually part of the intake manifold. My Apologies on that.

You are likely going to have to keep trying, remembering that the rear housing is aluminum and is easy to score or break. The only thing that comes to mind is a SMALL bearing puller, if there is a lip on the back side for it to grip onto.
 

TollKeeper

Active member
370
33
28
Brighton, CO
Buick Ownership
2004 GMC Envoy XUV, 2001 Pontiac Aztek
I wonder if you may be able to get to it from the thermostat side. It looks like there might be enough room to get your fingers in there, or a screw driver to tap it out, and break its bond? Just an idea.
 

G-345350

I wonder if you may be able to get to it from the thermostat side. It looks like there might be enough room to get your fingers in there, or a screw driver to tap it out, and break its bond? Just an idea.

Yes, thanks. That's what I did. Removed the thermostat housing and got behind it with a small flathead and a maul. And as you said, I was very nervous about damaging the aluminum.

She's all put back together now. Thanks for the input.
______________________________
 

ronaldsjodin

New member
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0
1
Buick Ownership
2005 rencezvous
Addendum: Found out something interesting. I realize now why the first inlet tube was sealed in place with permatex. Look at this picture of the ends which are supposed to go in the thermostat housing.

View attachment 20101

You can put a finger in the thermostat housing and feel the rest of the tube. Some jackass must've snapped it off and, rather than extract it, just cut one to length then mashed permatex all around it (which I must sheepishly admit was my first idea for fixing this too).

So then, the question is how to get it out. A hook tool maybe? I couldn't get a grip on it with my needle-nose.
 

ronaldsjodin

New member
3
0
1
Buick Ownership
2005 rencezvous
Tap it in opposite direction it was installed with a screwdriver thru thermostat opening using a socket size of the bore. do not use screwdriver alone as you may scratch the sealing surface
 
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