Hi, I have a 2011 Toyota Sienna, my car overheated and when I took it to the mechanic he told me I have a blown head gasket, so he recommended I do blue devil for head gasket sealer, which I did, since then it's driving okay, but 1, I'm worried because when accelerating on the highway the temperature gauge starts going slightly down towards "cold", 2, the coolant in the reservoir which is supposed to be pink is a more brownish color now ( you can still see pink in it) are these 2 things anything to worry about and if yes how do I go about it thanks Scotty!
There really is no expectation that some miracle in a bottle is going to fix a mechanical problem like a blown head gasket. Such products are temporary bandaids at best that may work for a period of time or may not work at all. The only sure way to actually repair a blown head gasket is to replace it.
There is a high probability that the product didn't work, at least not completely. You might want to test your coolant for the presence of exhaust gases.
https://www.youtube.com/watch?v=v0U8Iyf0kk4
you should probably change your coolant and thermostat
