July 06, 2012 00:00 By Pattanadesh Asasappakij
A very common vehicle breakdown faced by Thai motorists is engine overheating.
There are many degrees of overheating, but if it comes to the point where the engine stalls, you can expect a long list of repairs.
Many times mechanics advise the vehicle owner to purchase a new or used engine, which is easier than attempting to repair the old engine.
This kind of advice usually encourages and convinces the car owner to replace the engine, despite the fact that it is in no way better than overhauling the original engine damaged from overheating.
The main reason for this advice is that the mechanic takes less time to finish the job (at least half the time) and makes more profit even if the cost of replacing the engine is cheaper than repairing the old engine. The price factor also convinces the car owner to follow the mechanic’s suggestion.
Mechanics these days have very little experience in repairing engines. That’s why whenever they attempt to overhaul an overheated engine, they are not able to restore it to its original condition. Overheating is a problem that Thai motorists dearly fear, and many foreigners who come from cold countries have difficulty in understanding this fear.
Today many of the smaller passenger car models sold in Thailand do not come with a water temperature gauge as standard equipment as in previous generations of cars. Many buyers who have experienced overheating actually decide to pay extra for a higher model that comes with the gauge.
However, first-time drivers have no problem in purchasing cars without temperature gauges since they have never had a bad experience before. They go about driving without having any second thoughts about the engine temperature.
There are many reasons why the engine stalls after prolonged overheating, but in the end both mechanics and car owners come to the conclusion that “the water in the cooling system has dried up”. They forget to think that there are many ways in which the water can disappear.
It could be due to a leak in the radiator or the water hose anywhere along the system, or the water could dry up because of an engine malfunction. The heat could rise to a point where the water evaporates. This symptom is something mechanics have a hard time dealing with, and even after a trip to the mechanic, the same problem comes back to haunt the owner. This is because the mechanic did not solve the problem at its origin.
Today I will talk about the different areas you should check if you suspect a leak in the cooling system (when the water level keeps dropping and you have to fill the radiator more often). Having to fill in 200-300cc of water every week is considered a highly irregular symptom.
The most common area for leaks is the radiator grille, but it is very difficult to spot with the eye during the initial stages. This is because if the engine temperature isn’t high enough, there will not be enough pressure to drive out the water through the tiny hole that Thais usually call the “ant’s eye”.
As the temperature rises and more pressure builds, the radiator gets hot, and sometimes the small amount of water that seeps out evaporates right away. Inexperienced mechanics may not be able to spot this, but those who are experienced will find it due to the water stain around the leak.
The next commom area is the water hose that connects the engine. The tightening belt may have loosened or the rubber hose may have been torn. There could also be rust that prevents the hose from fitting perfectly, causing a leak. The next area is the plugs along the engine manifold, which could rust and block water flow. The same goes for the radiator housing that is welded and could crack. These are the danger areas in the engine’s cooling system.
Now that you know these delicate areas, you can manually check for leaks without much trouble, except for the plugs which are located deep inside and would require professional help.
For other areas, the owner can also check by sprinkling talcum powder around and then starting the engine. Let it run until the temperature gauge reaches the normal level (this could take as much as 15 minutes for new models), or take it out for a drive.
Once you’re back, open the engine compartment and look around. If there is a leak it will be easier to spot due to the powder. This could make it easier for the mechanic to carry out repairs, since you have already found the location of the problem.