Volkswagen Repair: 1999.5 Jetta 2.0 Overheated and shut off wont start, jetta 2, air pockets

Question
I just purchased a 99.5 Jetta with 122000 miles, drove it home about 5 miles and left it running in my driveway as I tinkered with its features. It was idling for approx. 15 mins when I noticed the temp was at 190+ and it smelled hot/burnt then it shut itself off (I did not touch the key/did NOT sound like a stall out). Fear of damaging it I let it cool for several hours then tried to start it, it turns over and over but will not start/fire. Can hear fuel pump come on. Have no knowledge of VWs... It would be nice to drive it... Thanks for any advice!

Answer
Hi Will;
There is a relay under the dash that I would start with.  It is the "load reduction relay."  Turns off all consumers except the starter, and the fuel, and ignition systems while cranking.  The failure occurs, and there is no spark.  I don't know why, but it just happens in that fashion nearly everytime they fail.  If it is not the relay, you will have to do some other investigative work to track down if you have spark, or not.  Just because you hear the fuel pump, doesn't necessarily mean you have fuel either.  Maybe the fuel filter is clogged...yep, can happen.
The very first thing to find out is whether the previous owner changed the coolant....   If the previous owner did change the coolant, or the thermostat, or the water pump, it is highly likely that there are air pockets in the cooling system, and if so...they need to be removed.

However, as I continue to think about your problem, I guess I would first do a "leakdown" test of all 4 cylinders.  The head may have been where the air pockets were, and if it got so hot it quit, the head may be warped, and leaking compression.  A simple compression check isn't good enough.  Do a leakdown.  It will tell you for sure if there is a leak, and where it is.  Besides you don't want to crank it over, and over if there is fluid filling the cylinder without being burned, and leaving as exhaust gas.  The result there will be a "hydraulic condition."  The rods will bend, or break.  Sorry to hear about your trouble.  Get a "Bentley's" repair manual for your car, and any questions you have about what I'm saying here will be answered.

Good luck.