The first thing is to go straight back to the shop that did the work, especially since you only made it a mile or two. Waiting a day or longer makes it near impossible to prove they did something wrong which is what sounds like what happened. Your second best action now is to return and show them the bill from the second shop. Given the circumstances, that should have an itemized list of products needed that should have been handled the first time.
It normally takes well over a mile of driving for an engine to overheat, but regardless, it could be just a horrible coincidence that something else happened just after the service, but it's doubtful, and you won't know for sure until the cause is diagnosed. Everything you described could be caused by a leaking head gasket, which is common on all car brands, and that is not something the lube shop people could cause. Everything could also be caused by a punctured radiator, or, given the car's age, a corroded radiator. Depending on its condition, an insignificant bump to the radiator could lead to its leaking. The employee may have indeed bumped a corroded spot but that can hardly be considered his fault. I fought a mild running-too-warm problem on my '88 Grand Caravan many years ago that finally got worse in the winter. Eventually I had to remove it to solder a leak, and that turned into removing it five more times within three weeks to repair five more GROUPS of holes. It was just crumbling like a rotten chocolate chip cookie!
The thermostat is the last thing you should be thinking about. Starting with a cold engine, it takes a good five to ten minutes before it starts to open. You would also have really hot air from the heater if it failed to open. Given your helpful observation of cold air from the heater, there was either no circulation of coolant or there was no coolant TO circulate. With the leak you observed, that would tend to point away from a leaking head gasket. A radiator or heater hose could have sprung a leak. A hose clamp could be loose. I have a '80 Volare that blew the lower radiator hose off the radiator while pulling a trailer load of firewood. Come to find out there was no hose clamp on it. All that was left was a skeleton of rust where the clamp had been. It never built up enough pressure before that to blow the hose off because I had never made it work so hard. You could have something silly like that too.
You need to start by determining what is leaking. Since the puddle is big enough to see, that shouldn't be too hard to do.
By the way, do not draw any conclusions about the second shop filling your brake fluid. That should not have been done. Either you have a brake fluid leak or the front disc brake pads are worn to the point an inspection and possible brake job are in order. No oil change mechanic will ever top off brake fluid if they know what they're doing.
As for oil level, that can also be confusing to some people. All engines use some oil between changes now because of low tension piston rings. To address the many complaints of that usage, all dipsticks are marked now with "Min" and "Max" instead of "Add" and "Full". As long as the level is at or above the "Min" mark, it is okay.
Monday, June 25th, 2012 AT 2:24 AM