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Coolant leak from hard line


RYS

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I recently purchased a 1991 Cutlass Supreme with the 3.1L V6. It's a great car so far I've only had to repair the oil pump o-ring. I was getting a low coolant light about once a week and I was adding a few cups of water to the overflow tank each time but no puddles so I feared the worst, intake manifold gasket failure. Finally I put a pressure tester on the system and it held 16lbs. The coolant was brown when I got the car so I drained it out and flushed the system. I added new coolant and replaced the thermostat. The next day it developed a leak. I guess the rust was holding it back. I could hear hissing comming from the TB area when the car was hot so I assumed it was those coolant hoses since I had taken them off for the o-ring replacement. I did the TB bypass and started the car it was still leaking. The leak is comming from the hard coolant line comming out of the thermostat housing next to or near the Coolant temp sensor. It has a quick connect type platic fitting on it and that is where it's leaking from. Is there a fix for it or do I need to replace the whole pipe? Sorry if this has been covered I tried searching and didn't get a direct answer. Thank you.

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My 89 buick with the 3.1 did that when i first got it year before last, probably the best thing to do is while you are thinking about this kind of stuf, just go ahead and replace as much of the old plactic and rubber parts and tubing where you can, and the metal tubing should also be checkd.

also a HAYNES manual works wonders....

 

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So do you know what the tube is called? Any part number? I want to head to the dealer first thing in the morning to get this sorted out. Thankfully I live two blocks from a Pontiac dealership. (walking distance for parts :smile:)

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lol ur lucky i live 3 miles outta town, tahts good excercise... :rolleyes:

anyway that metal pipe is the outlet pipe to the heater core, also u may want 2 check the coolant temp sensor,(adjacent to the egr pipe) mine also had a pressure leak there, just a heds up suggestion....

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I had that exact problem with the hard line that runs along the passenger wheel well. If the connecting part of the metal is still intact, go to Autozone and get some rubber heating hose (they'll cut it to length) and some clamps. It does the exact same job! I've driven my car ~500 miles since then. It holds just fine. Just my opinion of course :high5:

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If you can't fit the pipe, I would suggest removing that POS quick-breaking connecter with a screw in brass hose-barb fitting on the intake manifold, then use as much heater hose as you need. Cut off the rusted section of the pipe, paint the exposed end and run the heater hose over the end and clamp it down good.

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Something like this correct?

 

2692_3lo.jpg

 

I think that is where it is leaking from, the fitting that goes into the manifold not the quick connect. Would I need to put something on the threads like teflon tape or some kind of sealant or just leave it at that?

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yea, exactly that, just make sure the flare is big enough (5/8 or 3/4, can't remember which). I got away with not using teflon tape and just clamping it down good, but the tape would probably be a good idea.

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Ok so I was out in the garage trying to get the fitting off. I took out the coolant temp sensor and put the wrench on the fitting and it turned with no resistance. It is corroded to shit. In this pic you can see it is disconnected from the manifold at this point. There are still threads sticking out of the manifold. Are these a seperate piece or are they part of the connector and need to be removed?

 

img00163rb9.jpg

 

Thanks for all your help guys you're making this nightmare easier.

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That is all onee piece. The treads are part of that metal piece that your teying to get off. Just take it out.

 

and you might or might not be able to use teflon tape. I used a thread sealer ( its actually a paste ) that is more designed towards plugs and such in the water system like in the bottom of the block. Thats going to work much better than teflon tape

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go with the brass, quick connect is CRAP... lol or just go with the more sensible 2 you which ever that may be....

that just my opinion and its not my car so i can't really tell you what to do just give sum suggestions...

 

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:evil: :evil:

 

So I got the corroded piece off... in pieces along with the quick connect plastic also in pieces. Now the threads that were still in the manifold are still there. The metal was so soft when I tried to turn it out with some pliers it just crushed and broke off. So now the threads are stuck in the manifold and the metal is very soft. This is turning into a disaster. I dont want to go poking around in there and ruin the aluminum threads in the manifold. I'm gonna try and pick it out or I'm not gonna be able to put anything new inside of it... wish me luck.

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Tried drilling it I can't fit a drill in there even if I were to remove the fuel lines and TB. I tried chiseling I cant swing the hammer too much. I got a few small pieces out but thats not gonna work deep in the threads. I think I'm left with no choice but to remove the Lower Intake Manifold and work on it while it is off the engine. This would be a good time to replace the gasket I guess, not that it is leaking but oh well..

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Sounds like what happened to me on my truck. Luckily, it was when i was replacing the the intake gasket and i had to pull the manifold anyways. I had the right size tap and drill bit, so i just drilled it out, re tapped the hole and put in the new one.

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I replaced the coolant quick connect on my Z34 ( same as that one ) with a new one from GM.

 

 

 

The replacement ones are built more heavy duty and should cost well under $20. The plastic piece is included as well.

 

Can you find an easy out (screw extractor) that is big enough at at hardware store near you? (kind of like a tapered reverse drill bit with no spiral).

 

 

Otherwise I would try some visegrips or a pipe wrench if you have some threads sticking out of the LIM.

 

If not......a new LIM could be had for cheap from a junkyard.

 

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Yeah, I'll get it done. I do all my own work because I enjoy working on cars but I've never done anything this involved. This is my girlfriends car so it is worth it to me the car is in excellent shape does not burn or leak a drop of oil. It was a one owner a little old lady who took care of it. It sucks because the day it started leaking we just had 4 new tires installed and didn't even get to put 100 miles on them yet! I should have the car back up and running sometime next week. Thanks for the support I'll post up some pics of the process.

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Well I'm halfway through this. I got everything out now I gotta drill the hole and tap some new threads in for the barb fitting.

 

heres a few pics

 

enginead7.jpg

I may have splashed a few drops of coolant into where the cam is should I change the oil?? It's not like it dumped in there just a drop or two.

 

partsmesswt8.jpg

the mess of parts

 

corrosionag6.th.jpg

Here's the problem at hand..

 

cuttyvz0.jpg

 

And a shot of the cutty undergoing surgery!

 

This is actually pretty fun. Now I have to locate a torque wrench and install my New upper and lower intake manifold and valve cover gaskets. I got the Fel-Pro set hopefully this will be good. I got some Permatex Ultra Copper RTV to go with everything. While I got the motor unhooked I'm throwing in a new PCV valve some AC delco plugs and cheapo set of wires.

 

 

 

 

 

 

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