I bought a 90 740 GLE wagon with roughly 100k miles on it. Within a few months of my buying it, it overheated at highway speed. I have to admit, I didn't catch the problem until it boiled over. I had noticed some hood discoloration when I bought the car, so I think it had boiled over pretty badly at some earlier point.

Anyway, I pulled over, let it cool, added water, etc. The hose from the radiator had blown off, so I re-attached it, and later had it replaced. My reasoning (incorrect) was that a bad hose clamp had led to the overheating. Car ran well, although sometimes somewhat hot, for two years. I put 35k on it. Recently it overheated during a long hot drive. I nursed it along with water every 30 minutes, and kept it out of the temnperature red zone, but it was leaking water all around the water pump, and the coolant was orange.

Took it to a shop, and they replaced the water pump and did $500 of brake work, then noticed that the head gasket was shot, as well as a freezer plug. He said it would cost $1100 just to pull the head and look, and he had me convinced it wasn't worth the risk, although I still owed him for all the other work.

I was gonna junk the car, although I just got new tires and wheels, as well as a starter and some other stuff within the last year, and it has no rust or other problems. I called another garage, and he basically told me that he could do the gasket for $850, and even if the head is warped, it was no big deal to machine it or get another used one.

I had the car towed from one garage to the other, which got the first mechanic mad at me (I paid him) and I'm hoping for the best.

My question is, why is this car having so many problems relating to head gaskets (among the receipts that I got from previous owner was one for head gasket replacement) and overheating? Is it probable that the engine is screwed up in a deep way? It always ran strong and smoothly. Why would the water pump, head gasket, and freezer plug all go at once?

Any insite?