By now, I've read about 15 or 20 of these comments posted about '89 - '95 Toyota 4Runners and how their head gaskets blow out and how so many people are upset and disapointed. Now I too am a victim of this happening, but what I wanted to say is that people!! You need to do your RESEARCH! All cars have their problems. and '89 - '91 4 runners, because of the design of their engine, their gaskets WILL BLOW. There is no getting around it! I recently purchased a beautiful '95 4 runner with a V6 3.0 liter engine with a blown head gasket. My father and I bought this vehicle knowing it needed to be fixed, and we continued to replace the head gaskets in the engine.
Now, for those of you who know that they need to do a little research before buying a car.. I hope this comment serves you well!!
In simple terms, when the V6 engine model for this truck was manufactured, they Japanese had a brilliant idea!! "Lets make the engine lighter by putting aluminum heads on the engine instead of steel, so that it in turn will be lighter, and run faster." Yes it was a good idea, but every idea has a pitfall. And the pitfall to putting aluminum heads on a steel engine block, is that they are two very different types of metals. The problem comes in when you get around 100k miles, the heat from starting, running, stopping, cooling, heating, cooling, heating, cooling (etc) of those aluminum heads, the heads expand and detract with the various levels of heat. And since the engine block is steel, there is no expanding and detracting of the metal. SO! When you get that one metal moving around, it affects the gasket that is sealed between the block and the heads. And after so much heat and tension (typically around 100k -150k miles) those gaskets crack. In turn, water and antifreeze is able to leak into the oil and which causes... WHITE SMOKE!
White smoke and poor running quality of the engine is the effect of this blown head gasket, which is the effect of the poor motor design.
But hey, no one and certainly nothing (especially cars) are perfect. So please people, do your research so you don't have to cry and moan later when you figure out what certain cars' problems are. It just might save you a lot of heartache, and wallet pain too.