How can you prolong a weak head gasket in your engine?

Have a '94 BMW 325 that was loosing a quart of coolant per 400-500 miles. It runs with a 2B radiator pressure cap (29 PSI). Engine would expel steam on start up for a minute or so through exhaust. Loosening cap about 1/8 turn reduced pressure to 10-15 PSI. and start up steaming & coolant loss stopped. Most cars will require a different cap w a lower pressure rating but this cap is threaded so loosening slightly works perfectly. Lowering pressure will allow coolant to bubble at a lower temp but systems are designed to withstand temperature extremes. At 105'F, my temp gauge still stays at normal (1/2 way). Have driven 20,000 miles under this condition without ill effect.

My opinion. If you want the engine in your car to last, STOP driving it period until you have a leaking head gasket repaired. There is no such thing as a weak head gasket. It is either doing it's job or it isn't. A leaking head gasket allows coolant to enter the combustion chamber or the oil drain holes. Either way this will contaminate your oil and cause severe wear of all engine components. Someone my tell you they drove for 20,000 miles with a bad gasket with no ill effect, but how would they know without opening the engine up? They are just kidding themselves. You will have wear and that is a fact. The only fix is to replace the head gasket and there is no other fix. Coolant and oil mixed together equals engine wear.