So, I have a 1992 300D. Here's a bit of the story. A little over two years ago I started having overheating issues with my car. It was getting way too hot and going through a lot of coolant. After many trial and error tests one day I went out to it and it was water-locked. Which means, head/head gasket issues, right? Yeah, and thus started the long process of taking off the head and replacing everything. We took the head in to a machine shop who planed, cleaned and inspected it, got it to good-as-new condition.
At this same time I was preparing to leave the country for two years and would leave the car with my dad to take care of and drive every now and then. So we were putting the head back on, following very closely every detailed instruction that we had (we had some sort of step by step print off thing, maybe I still do). We got it back on smoothely and everything and then came the time for me to leave, and I left, leaving my almost-ready-to-run car with my dad. He soon got it running and started driving it about once per week, just to keep it nice enough for me to come back to.

This worked for about 8-10 months, then. . . he went out one day to find that it had no electrical power to anything. The next months included many tests and failures to find the problem. After many months of the car sitting he was able to tow it to a mechanic who found out that the positive cable had been grounded and this was the cause of the electrical issue. They also did a pressure test on the coolant system and found no problem, BUT, they think that the head is cracked or the head gasket is blown (bran new) because it's still losing coolant.
So I've a few questions. Would a car still pass a pressure test if the head was cracked or the head gasket was blown?
What can I do, without taking the head off, to know for sure if it's cracked/gasket blown?
Could the head have been cracked the first time I took it off and the machine shop just did not detect it?
Is there anything that we could've done wrong in the re-application of the head gasket or head that would've simply misplaced the gasket or worse, cracked the head?

Any help would be great. Right now I'm re-looking at the option of re-tearing apart my car, or if worse comes to worse groancoughsellingitforpartscoughgroan, or something to that effect. I just want to be sure before I make a decision.

Thanks

 

How hot was way too hot? How much did you have to take off of the head when you re-surfaced it? How much coolant are you loosing? Are you getting water vapor out the tail pipe? I might suggest a cooling system leak-down test. Warm the engine up then put a pressure tester on the radiator, and pressure it up to about 17 psi. then the same proceedure with it cold. The reason for doing it both cold and warm is because different cracks will leak at different times. For instance if a cylinder is cracked length wise it will tend to leak cold, but not hot. A crack in an exhaust port of the head usually blows the coolant out the top of the radiator, and seals back up when cooled off, a gasket leaking into the cylinders can do the same thing, a crack around the radius of the cylinder will tend to leak hot, but not cold.
I hope this helps make things clear as mud for you.