Hello and thank you for your question.
What year Make and Model Car is this? You used Stop Leak in the Coolant system?
2004 Pontiac montana
So you used Stop leak in the coolant system? is that correct?
That stuff is the worst...
Let me explain why.
well it was recmended by a mechanic
Well that mechanic that recommended it just clogged up your coolant system..
That stuff restricts coolant flow and can screw up radiators, heater cores and thermostats
Stop leak is only for emergency situations and is not to be used as a fix.
is there any way to clean it out
You need to flush the whole coolant system out with a hose...
to get that junk out...
Then fill it with coolant and bleed it and see if the issue continues..
Then check the temperatures on the hoses to see if there is any more restrictions..
While the car is running with the heat on..
Pontiac service told use we had a bad head gasket is why we put the stuff in
If you have a bad head gasket, that stuff won't fix it..
That just clogs up the coolant system and causes over heating issues...
I am sorry to say, not only will the head gasket need to be replaced if leaking, but now the coolant system will need to be totally flushed out..
what will it take to flush it out?
What do you mean?
can I just use water to flush it with
Yes, use water to flush it all out.. You want to use a garden hose in the system to flush it out..
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