Cost of an Overheat

Atribución Some rights reserved by Rafael Marquez Photography

Our first recommendation is to use VR-12 and avoid problems with your car, however, it is very useful to know the cost of not doing so.

This article is written primarily for the car owner. Professional Auto Techs know this information all too well, and most do it yourself mechanics  know it also. Anyone not knowing this information leaves himself vulnerable to making some very bad decisions that will cost a great deal of time and money.Sometimes you get lucky and an overheat can be corrected by fixing its root cause. But all to often, overheating — even a single 3 minute incident — can cause consequential damage that costs thousands to fix. An overheat is a very bad thing.

The most common consequential damage is a broken head gasket. This happens when the head and block expand differently than the head gasket, or even worse, when an aluminum head and a cast iron block expand at radically different rates, breaking the head gasket. Bimetal engines, whether they be aluminum heads on a cast iron block, or cast iron heads on an aluminum block, are likely to break head gaskets with the slightest overheat. Unfortunately, replacing head gaskets is a big job requiring hours for even an experienced mechanic with all the right tools. For a do it yourselfer, it could be prohibitively time consuming or even impossible. As a result, the cost of replacing a head gasket ranges from $500.00 to $2500.00, depending on the make and model, and whether the heads must be machined.

Broken head gaskets result from a moderate overheat, or even a mild overheat on a bimetalic engine. A more serious overheat can bend or break the heads. Now you have a large parts cost to add to the huge labor charge for replacing the head gasket(s). New heads cost hundreds, and machining heads is also costly.

Some folks consider continuing to drive the car with a broken head gasket. That’s a very bad idea if you want to keep the car more than a year. Combustion gas in the coolant can easily cause even more severe overheats, plus it can quickly cancel the anti-corrosion properties of your antifreeze, leaving you open to corrosion, leaks, and blockages, all of which result in further overheating. If coolant gets into the oil, the oil’s lubricating ability is compromised, leading to engine seizes, bearing freezes, and all sorts of other problems. If coolant gets into the cylinders it can cause a broken starter, solenoid, or flywheel. Broken head gaskets often make the car run poorly, and often make it a gross polluter, which can be costly indeed in states that enforce smog regulations.

Your engine was designed to operate at a certain temperature. When it operates colder than that, emissions go up, efficiency goes down, and engine wear increases. This is why cars don’t drive as well cold as they do when they’re “warmed up”. On the opposite end, cars operating hotter than designed, even at temperatures lower than what it would take to break a head gasket on a cast iron block/head combination, risk pre-ignition/detonation caused by too-high engine temperature. Such pre-ignition/detonation can damage various components in your engine. If you’ve ever driven a seriously overheated car you know it sounds much different, and it doesn’t sound good.

But what if you’re one of these wild and crazy guys who doesn’t shut down the car even when the temperature gauge is pinned, there are huge clouds of steam coming out the hood, and the car has started running funny. You, my friend, will most likely need a new engine. Extremely overheated engines seize, freeze, warp, and who knows what else. Engines aren’t too expensive, but the labor is prohibitive, and all too often the new engine lasts 10,000 miles and then blows up.

Added to those costs is the cost of having an unreliable vehicle. Cars that overheat once tend to overheat often; unless an unusually competent and comprehensive repair job is done. Overheats results in a tow charges, missed work, and even hazards to personal safety. It’s doubtful anyone’s personnel record lists “broken head gasket” as a cause for job termination, but it just might list “excessive absence” and “unreliability”.

I hope I’ve gotten your attention. A single overheat can cost you thousands. You need to know that, because during the rest of this magazine I’ll be recommending preventive maintenance that costs nearly $100.00 per year, and diagnostic procedures which cost almost $100.00 not counting the actual fix. When evaluating the cost of my suggestions you must realize the cost of the alternatives — $1500.00 to fix a head gasket, $300.00 for a new radiator installed, and if you go to an incompetant Automotive Technician who practices diagnosis by serial replacement, you’ll spend even more.

When viewed alongside the alternatives, $100.00/year to keep your cooling system healthy starts sounding downright cheap.


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