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Discussion Starter #1
My 08 GT with 150K miles has a miner coolant leak.

I tried looking for the source and saw some vapor behind/underneath the driver side radiator fan, but couldn't find the actual leak.

Any idea what it could be? Are there any decent safe off the shelf stop leak products?
 

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Stay away from stop leak products, they cause more problems than they fix IMHO.
Get a bottle of coolant dye and put it in cooling system run for a day and get the light needed to trace the leak.
Or get a pressure test done on the system to look for leak.
I had my coolant leak traced at the dealer, others here may know of kits you can get that do the same.
Just keep in mind these leaks migrate everywhere and sometimes take some real detective work to find.
My leak was a 4 week, multi visit ordeal and in the end the guy tripped over the leak.
 

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No, you don't want to use any of that stuff. It isn't necessarily that the AC Delco tablets will do damage. It's because you don't know where the leak is or the nature of it. Check your hose connection on that side to see if it is coming from there or if it is coming from the cap.

A bad cap is cheap, but if it is coming from the radiator hose connection, you need to drain the system and get the hose off to check the plastic barb for wear. The glycol will turn to acid if not changed often enough, it is an inevitability for glycol especially in these conditions. They break down into their base acids once the inhibitors are "used up" so-to-speak.

I suspect you aren't comfortable draining it, so bite the bullet and take it into the shop. :)
 

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Discussion Starter #5
With the current weather we are having I'm not inclined to do anything.

I drained the radiator every two/three years and topped it off. Never performed a full flush though.
 

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So off to the shop you go. :)
 

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Was one of my favorites. I basically looked for Demo Cars to get a better deal and this one stood out from the rest. :) It is a nice color.
 

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Jova007200 nailed it.
Bars Leaks and the aluminum flake tubes you buy or any other sealer will stop the leak but for a time only.
But while stopping the leak they plug up your heater core and generally plug up anywhere they can gain a foothold in the cooling galleries in the engine.
I had an old van that had a leaky head gasket, it must have weighed 500lbs more for all the stop leak I poured in it. Each dose only lasted 3-4 weeks and I froze to death in the winter but I got another 2 years out of it. It was the tranny that finally went because the trans cooler/lines were plugged up....plus I didn't give a damn about it not like my G8.
Not what you want to hear but off to the dealer or a shop.
 

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Discussion Starter #10
Small leak in the bottom of the radiator. Who figured a plastic radiator was a good idea?

I'm getting the shop to take care of this. Single digits temperatures are only good for staying in a warm house and napping.
 

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Unfortunately, metal or plastic, a radiator is eventually going to leak. :(

Glad you found out where it is.
 

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Discussion Starter #13
After replacing the radiator should I throw in a tablet of the AC Delco Cooling System stop leaks for good measure?
 

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After replacing the radiator should I throw in a tablet of the AC Delco Cooling System stop leaks for good measure?
Always use distilled water in lieu of tap water and it should be fine. Although, at least one forum member had leaking issues with a couple of brand new Ac Delco radiators.
 

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Am not readily familiar with the Ac Delco Stop Leak tablets and one use the one made under the JB Weld brand.
 

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IF, a big if, they are the same as years ago they are ground up walnut shells compressed into a tablet.
I would think technology has come along though....
 

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Discussion Starter #19
Sadly a little over a year later there's a small leak in the same vicinity on the driver's side.

Going to take it to shop again.

If it's the radiator, what's the conventional radiator warranty?
 

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Length of warranty depends on the manufacturer and could be anywhere from three months to limited lifetime. Was the radiator cap replaced as well?
 
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