Mechanic came back saying my truck has a blown head gasket and it needs a new engine, (A 6.0 which would be hard to find a used one that doesn’t have over 200k miles) it seems to be a very small head gasket leak cause it doesn’t loose very much coolant. Truck was driven about 15k miles with a blown head gasket without knowing as i thought it was just a coolant leak, Should I get a sealer like Blue devil or go through the work of taking apart the engine to replace them. Thank you. (2004 GMC Yukon XL 2500)
As folks have already mentioned, a blown head gasket does not mean your motor is trash.
What diagnostic’s did the mechanic perform?
Have you had the mechanic do other work for in the past?
What symptoms, other than losing coolant, have you been experiencing with this truck? Do you have coolant in your oil?
If in fact you do need a different motor, in the quick search that I just did on car-parts.com, I found at least 5 6.0’s within 2 hours of my house that have less than 150K for less than $2500. They are out there as they made a lot of them,
Get a second opinion on this before you jump to swapping motors because based on the VERY limited information you have shared, it’s hard to say what to do.
Also, until you know where your leak is, I would not use any of the additives to try and stop a leak as that will make diagnostics that much harder.