Radiator Stop Leak for IM gasket leak? [Archive] - GrandAmGT.com Forum


View Full Version : Radiator Stop Leak for IM gasket leak?

03-24-2004, 10:40 AM
My 99 GAGT is leaking coolant but showing no signs of mixing with the oil, not running any hotter, etc.

I read here in this forum that the gaskets fail causing an internal leak (mixing with the oil) or fail causing an external leak (basically just making a mess).

Do any of the "Stop Leak" type products help the external type of gasket failure? Or is replacing the gasket the only way to fix it?

03-24-2004, 02:56 PM
I had a slow leak for 9 months, and it didnt go into the oil. I would NOT use stop leak i used it and it turned my dexcool into some foamy stuff. You are just gonna have to get the gasket job done from 400-600 id guess, but itd be a good time to do a upper and lower port/polish job

03-24-2004, 05:24 PM
I used the prestone stop leak. It worked and was far cheaper than getting the gasket replaced. I've also used it when the dealership didn't install my radiator right and a hole got worn into it.

Ya, it'll make the dexcool look like crap but it still cools. Car has 120k miles on it now first used the stuff around 20k, so no adverse effects yet. Just don't let the coolant go for the 150K advertised life of the dexcool.

btw, a p&p job is pointless and a waste of cash unless you are running forced induction, larger cam or N2O. Especially if your heads aren't ported to match. Why blow a couple hundered $ for maybe a tenth of a second on a already high 15 sec car?

03-26-2004, 06:37 AM
I'm not a fan of the stop leak stuff, but it can actually work if the leak isn't too bad. It does make the coolant look like crap, but it still works and for some reason doesn't block up the radiator or the heater core either. It won't hurt to try it, because if you have the job done later on, they'll flush the whole cooling system anyway.

03-26-2004, 07:13 PM
I'm going to try something called Silver Solder powder. The Master tech at work used it for 2 months in his dually (still hauling horses) until he had time to fix it. He had no problems with it at all. And besides, when you do get around to fixing it, you have to drain the coolant anyway, and that'll get most of the leftover nonsense out of there.

Like I said, I'll be trying that stuff tomorrow, and as soon as my manifolds get here within the next couple weeks, I'll actually fix it. I'll let you know how well it works for me.