slow coolant leak
Thread Starter
Intermediate
Joined: Oct 2007
Posts: 34
Likes: 1
From: BLACKSBURG VA
slow coolant leak
OK I have searched through the forums for 2 hours, no real answers...
About 3 months ago I noticed some fluctuation in the coolant temp (noticed it when i had poor heater output) and found coolant low in pressure tank. No visible signs of leak anywhere. No rough running on startup. No smell in cabin when heater running. No fog on windshield. So I topped up the tank, ran the car some, topped up again, and everything seemed ok. I borrowed a pressure tester, pumped to redline, overnight no leaks, no pressure drop AT ALL. I've now driven for about 1500-2000 miles.
Now I have the same problem again - temp fluctuating, low coolant.
HELP
About 3 months ago I noticed some fluctuation in the coolant temp (noticed it when i had poor heater output) and found coolant low in pressure tank. No visible signs of leak anywhere. No rough running on startup. No smell in cabin when heater running. No fog on windshield. So I topped up the tank, ran the car some, topped up again, and everything seemed ok. I borrowed a pressure tester, pumped to redline, overnight no leaks, no pressure drop AT ALL. I've now driven for about 1500-2000 miles.
Now I have the same problem again - temp fluctuating, low coolant.
HELP
Le Mans Master
Joined: Feb 2002
Posts: 6,937
Likes: 21
From: Waldorf MD
Go to an auto store and get a tube of powder sealant, I think it's called aluma-seal (or aluminum-seal) for the radiator. Put it in problem solved. Note: In the future, if you flush your radiator, you may have to use it again. I have used it in several of my cars, including my Corvette, with no problems.
It is called AlumAseal, here is a link:
http://www.goldeagle.com/brands/alumaseal/default.aspx
It is called AlumAseal, here is a link:
http://www.goldeagle.com/brands/alumaseal/default.aspx
Last edited by Oldvetter; Mar 7, 2012 at 04:44 PM.
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
That's not the way to solve the issue. Sure it's a possible fix for a problem when you don't have the option of a real fix(i.e) on the road. BUT you should really have it inspected and actually determine the reason for the loss. Even pull the dipstick and check for water in the engine block, head gasket leak, or even a leaking water tank. BUT DON'T USE a temporary fix for a permanent repair.
Melting Slicks
Joined: Jan 2009
Posts: 2,127
Likes: 33
From: Easley/Anderson South Carolina
I had the exact same issue when I first bought my car. I found that the Peacock part of the radiator had a split in it. I would only leak under higher pressure in the system and not when I remembered to look for the leak. I found it when I pulled the radiator due to another repair.
Le Mans Master
Joined: Feb 2002
Posts: 6,937
Likes: 21
From: Waldorf MD
Hey guys, GM recommended use of "pellet radiator sealants" with every refill of the C4 radiator. Just saying, when it is a minor leak like the OP has (it takes 3 months to go low), I think this is acceptable.
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To find your leak, have a mechanic put some dye in your cooling system and then they can use a special light to determine where the leak is coming from. Have had this done on a few of my cars and it works very well. Keeps you from replacing unnecessary parts.
Thread Starter
Intermediate
Joined: Oct 2007
Posts: 34
Likes: 1
From: BLACKSBURG VA
ok thanks for the discussion. will try the dye after jacking up and looking carefully (i have already spent many minutes under the car and hood-diving looking with no joy). if no luck there might try a radiator sealant.
Melting Slicks
Joined: Jun 1999
Posts: 2,263
Likes: 48
From: NJ
DO NOT use sealant pellets! That's what can cause Dex-Cool to turn into "Jello".
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Melting Slicks
Joined: Mar 2008
Posts: 2,440
Likes: 338
From: SC
You can do this yourself. Get the dye at an auto parts store and a small blacklight flashlight. This helped me find my small leak. (which was loose hose clamp at the reservoir nipple, only a few droplets underneath, but I could smell it)
Le Mans Master
Joined: Aug 2009
Posts: 5,197
Likes: 190
From: ALL governments are legalized mobsters, so doesn't matter where I live :(
How many miles do you have on your car? If you bought used do you have any maintenance records? Like others have said, don't use any kind of sealant!!! If the car has high miles, and you still have the stock rad it could be your plastic end tanks are beginning to get hair line cracks almost invisible to the eye. Also check around the surge tank where the hoses connect on the "T." This is also another notorious location for leaking.
Instructor
Joined: Apr 2009
Posts: 108
Likes: 0
My car has a small leak at the reservior nipple right now, i smelled it first, but one sunny day I popped the hood and saw a little bit of coolant foaming right at where the hose meets the nipple. Coolant is still almost full, at the rate its going it would take 6 months for it to get low. Im going to replace the clam and epoxy the nipple.
Thread Starter
Intermediate
Joined: Oct 2007
Posts: 34
Likes: 1
From: BLACKSBURG VA
OK i have pulled the shroud and inspected the radiator as best I can without actually removing it. No staining at all. nothing around the H2O pump. I have asked my mechanic about a dye and he didn't have a suggestion. checked every hose, and the surge tank...
My daily driver car has 160,000 miles, and I was worried about head gasket, so I bought compression tester, pulled plugs, looking for side-by-side low pressure cylinders, supposedly a clue to bad head gasket. all tested between 185 and 192. ALL of them. replaced plugs and wires ( i guess 160k is about time to do this).
I don't want to put in any stop-leak product, so I guess I'll just drive it till it gets worse.
Appreciate all the suggestions
My daily driver car has 160,000 miles, and I was worried about head gasket, so I bought compression tester, pulled plugs, looking for side-by-side low pressure cylinders, supposedly a clue to bad head gasket. all tested between 185 and 192. ALL of them. replaced plugs and wires ( i guess 160k is about time to do this).
I don't want to put in any stop-leak product, so I guess I'll just drive it till it gets worse.
Appreciate all the suggestions
