What is eveyones thought on putting GM stop leak into a radiator? My mechanic suggested since he can not find where the leak is coming from the coolant system. Thanks.

 

Don't do it. Find another mechanic.

 

A mechanic suggesting a "mechanic in a bottle"!!
I would look very closely for the leak...many "common" spots on both cars that non-mini folks would miss....
The leakstoppers can cause issues.... Just cause it says "gm" as opposed to bar's stop leak, Preston's stop leak or even pepper flakes or egg whites does not mean a temp fix will work for long...thing about leaks...they are a warning that something BIG might be coming up...like the weep hole in the water pump.... Catch it now...you can fix it WHEN you want..later it is when the towed in is certainly less convient, and more $$$.

 

The "mechanic", and I use the term loosely, is an idiot. Do not, under any circumstances, put that crap in your car.

Remember, it doesn't just go in the radiator, but it does go to all the places coolant goes.

To be more helpful, buy a Tracerline leak detection kit, (about $70), find and fix the leak correctly.

 

This, and inspect everywhere very closely for the marks left by the escaping fluid. Now, some coolant loss is normal out the expansion tank pressure relief hose, how much are you losing in hot weather? And if you had an "air bubble" at one time, it can "burp" a few times before you get it all settled out which both spits out fluid because of steam pockets and makes the reservoir look low as the "air bubble" works its way into the expansion tank.

As for the mechanic, I might use stop leak on a small block chevy with a 4-core steel radiator but not on a tiny Mini motor. If the radiator is in doubt just replace it as it is cheap insurance against what can happen in less than a minute if a seam lets go. I'm sure the mechanic checked the water pump weep hole, it is the most common place a hidden leak comes from on any car.

 

Thank you for all your replies. I did not put stop leak in my radiator. I did not relish the idea of the stuff going thru my engine. I am a bit protective of my car. I do like the idea of the leak detector and getting the problem fixed once in for all. I did have my water pump and thermostat along with all the rubber parts replaced with new. The radiator and overflow tank are going to be next. The little mini is 10 years old coming from Rhode Island with a little rust. The car now lives in the south. Ya'll have helped me in the past and have been very helpful. Again thank you, rocysuja.