I recently purchased a used car that seemed to be in good condition. The engine started easily, ran smoothly, and performed well. But shortly after, a number of engine problems began to appear. What could be causing this? — Darius
Engines wear out, but usually very gradually and only one thing happens at a time. If several things go wrong at about the same time, the engine has probably been damaged beforehand – most likely by overheating at some point. Strange noises and/or a smoky exhaust are usually clues.
While a momentary overheating may cause little or no damage, severe, sustained overheating changes the temper of metals and causes warping, can burn valves, break piston rings and other moving parts, scratch cylinder walls, blow gaskets and seals and cause leaks, degrade lubricants, warp bearings, and eventually even break connecting rods.
As this damage progresses (from minimal to massive damage within minutes), the engine tends to first stall at low engine speeds and eventually “stalls” completely.
Even if the engine is shut down before these consequences become dire, and the engine appears to run normally once the cooling system is repaired (and hopefully the oil is changed), all of the affected components may have “aged rapidly” and subsequently begun to fail in an almost simultaneous series of problems.
Most motorists will experience overheating at some point, and it’s not an immediate disaster.
If the engine overheats, even to the red line, but the driver spots the problem right away and stops to fix it, there’s a good chance no damage will occur.
The red line is reached when the coolant reaches the boiling point of water and simply means that the cooling system is not doing its job properly.
But if you continue driving without a fully functioning cooling system, the temperature of the components inside the engine (which the gauge doesn’t measure) gradually rises, reaching temperatures that even the hardest steel can’t live with.
Even if you stop before those components deform or fail, they will weaken and change, and you have something between a series of problems or a complete disaster waiting for you.
For prevention, get into the habit of checking the temperature gauge frequently while driving. Even if the coolant level is “always” good, don’t stop checking the hood regularly.
The gauge should never go above the “normal range”, even under stressful conditions. If it does, even slightly, there is a weak point. Check the system. If the gauge approaches the red line, stop!
Find and fix the problem before resuming operation. If your car starts to stall at low revs, first and foremost, check the temperature gauge immediately.