I see a lot of Volvos in the ads that need new head gaskets or new engines. Is overheating always fatal?

 

Fatal? No. A headgasket is a rather simple job. Costly if you are paying someone else to do it. But, if you have the know-how, or the ***** if you don't have the know-how, it's a rather simple procedure. However, a lot of these cars get thrown away if this happens as typically the repair is either close to, or surpasses the vehicle book value at this point.

 

Define death sentence.

Overheating almost always guarantees a warped head and subsequent head gasket failure though.

 

It's never fatal because it can always be fixed. It might be considered "fatal" if the cost is more than the car is worth to that owner

There are two radically different ways to look at a 15 to 20 year old car.
It just had a major engine failure. One guy thinks it's time to junk it as it's not worth fixing and the other guy thinks it's time to finally build a better, stronger more powerful engine.

Overheating is a hard yardstick to use. There is normal operating temperature and then there is hot. Hot isn't necessairly bad but overheating is the range where damage occurs. Running hot isn't necessarily a sign of a problem. It can be the result of an unusually hot or very humid day and the added strain of AC where the radiator can't get rid of all the heat it needs to and or towing. It can also be a mechanical problem like crap in the radiator hampering air flow or the cooling fan failing or starting to fail or even the radiator getting restricted internally or just age and the cooling fins are corroding away. You might start running hot but that's not dangerous to the health of the engine. It is something to check out to find the cause as even when driven hard the engines cooling system should be able to shed all the heat a stock engine can produce. Modified is a whole new ball game.

One of the signs of a bad headgasket is the engine running hot or going hot and then dropping suddenly back to normal. It's caused but air in the cooling system building up or building up and then purging. I agree that overheating is the major cause of headgasket failure.

Overheating doesn't always cause a problem with the headgasket. It depends on the driver noticing the engine is starting to overheat (getting hot) and finding a place to pull over and shut down and towing it instead of driving. Or the guy with the radio blaring who doesn't notice the overheating until steam is billowing from the hood or the engine is knocking from pre-ignition because it's so damn hot. That will likely be a problem, a big problem.

When buying used I guess it's just safer to take it for granted the guy selling is the second of the two