head gasket and maintainence

[scottm]

I bought a car with a bad head gasket, and I hear alot it was due to bad maintainence. Im wondering how maintainence, could affect a head gasket or head bolts pulling out? assuming the car never overheated due to lack of or wrong antifreeze mix... the only way i see the bolts pulling loose is by very hard driving. Am i missing something about the maintainence thing?

Im having a used motor put in with supposedly low miles what would be the easiest way for me to check if headgaskets are in tact is there an easy check without leak down of carbon sniffer tests?

[Ranger]

If the coolant is negelected it looses it's anti corrosion additives get depleted and the gaskets will corrode from the inside. I don't think maintainance has any thing to do with the threads pulling unless the heads are pulled. Then the bolt hols must be "timeserted" (not helicoiled) or the bolts will likely pull during instalation or shortly there after.
The best way to check the head gaskest on the "new" motor is to pressurize each cylcinder with shop air to 120 psi thru the spark plug holes (with the valves closed obviously) and see if it holds pressure for 15 min. or if the is air bubbles in the cooling system. Since you'll probably do this before the engine is installed, also listen for an air leak in the exhaust manifold or at the radiator hose connection points to the engine but mainly watch the pressure so see that it holds.

[etcCanuck]

Unfortunatly, I experienced the effects of coolant neglect first hand. The head-gasket on the rear bank was corroded pretty bad. 5 year coolant is bulls***. When my headgasket went it showed up as exhaust in the cooling system. The exhaust would pressurize the cooling system and push all the antifreeze out. Then it would overheat. It sucks.