Mr. Goodwrench owes you more than a temporary fix.
I own a 1994 Chevy pickup. Early in its life, it developed an engine noise. After a few thousand miles, a new short block was installed in the motor under warranty. Now I have an interior coolant leak of some kind. I went back to Mr. Goodwrench, and with all his technology, he decided I needed a can of "dope" in the radiator. That's like putting bubble gum on a flat tire, isn't it? Will this cause me any problems down the road?
TOM: Will the dope cause you any problems down the road? Which dope? The one who put the stuff in, or the stuff itself?
RAY: If the dealer has determined that you have an internal coolant leak, and the truck is only a year old, he shouldn't "mickey mouse" the problem. He's got to fix it. You could have a bad head gasket, a cracked head, or even a porous block (yes, even if it's brand new). It's also possible that they caused the leak when they installed the new block.
TOM: They're either a) sick of seeing you drink their free coffee in the waiting room for days on end, 2) reluctant to go fight with Chevrolet on your behalf to get another major engine repair covered under warranty, or III) embarrased because they know they screwed up the block installation and don't want to admit it.
RAY: But whatever the reason, they owe you more than a can of radiator goop. I think, in the spirit of generosity, we should give them the benefit of the doubt. Let's assume they were just having a bad day. Let's assume there were six other angry customers--all bigger than you-- in the waiting room with baseball bats.
TOM: In which case I'd take the following approach: I'd go back and thank them for the fine job they did on the temporary repair. Tell them it performed flawlessly for the last week, and you were grateful to be able to finish the job you were working on. Tell them you're now ready to schedule the real repair, and ask them when it would be convenient for them.
RAY: And if they say "How's never? Is never good for you?" then save your repair order which lists their diagnosis and their first attempt at a cure. If push ever comes to shove on this one, that will be the basis of an extremely strong case, Phillip.