Informative read from Boosted Auto.Read on!
PROBONO THURSDAYS PRO MAX
A thermostat is a gate valve in the vehicles cooling system situated in between the engine and the radiator. Some more advanced vehicle manufacturers use electronic thermostat but for subaru, the mechanical thermostat takes the day.
For a long time, their has been a notion that every freshly imported car has to get its thermostart pulled off or else you stand a risk of encountering countless engine overheats. Well, this is not true. Infact this is a myth spread around by clueless technicians and vehicle owners.
Later in in this write up,we shall tell you why you need that thermostat in your engine but before we get their,lets first understand how a thermostat works.
A mechanical thermostat entails a special type of wax embedded in a brass/ copper housing with a spring loaded gate valve acting against the spring. Under normal temperatures, the thermostart is compresed, reducing its size while the gate valve is closed. When coolants temperature rises, the wax inside the housing melts thus increasing its volume hence pushing away the gate valve instantly opening the pathway. By so doing the gate opens and let’s the hot coolant to flow into the radiator for cooling.
Since this is a closed loop, an exchange of a cold coolant in the radiator moves to the engine while being replaced by a hot coolant from the engine. The action keeps repeating itself for as long as the engine is running in order to keep the engine at predetermined temperatures.
In the event that a thermostart is stuck closed an engine overheat will occur… on some vehicles the temperature gauge will rise high but in most subaru engines this is never the case. In our previous probono we reffered to this as silent overheat. Coolant will not leave the engine block to the radiator abd vice verser. The hotter coolant in the engine continues being hotter and hotter while the colder coolant in the radiator continues being more colder. Whatever proves weak in the colling system will rapture but before that you will experience lots of overheats and your trips to the garage will be triple your trips to work.
At this point your rogue technician will suggest a thermostart removal. Because your frustrations are are skyrocketing, you will agree and true to his word, upon removing your thermostart, your car will not overheat again. Your problems seems solved but the truth is you have just opened a can of worms for a different nightmare. Before we come to the can of worms let’s all understand why your car is not overheating after thermostart removal.
Previously, the cause of your overheat was a stuck thermostat. If you are lucky enough probably the overheat had not reached to the level of lifting cylinder heads and the head gaskets. So when the thermostart was removed now the coolant circulation is flowing freely without restrictions so automatically the temperature will not rise due to contamt conduction and radiation of heat happening due to free flow.
The right thing that shoukd have happened would have been to replace the thermostart with a new one, because the defect was already known. But because they told you that thermostarts are not for our country and you believed it without asking if that was the case then why do we have zero millage cars at the dealerships built for specifically for kenyan terrain yet they come with thermostarts.
So you will drive around a very happy man and spread the myth to everyone you meet having overheating problems. Then soon you start realising your interior heating system (misleadingly called the ac ya joto) takes time to heat your interior, your temperature gauge barely goes above quarter mark. It even drops further down to C (cold) when you are rolling down the hill. Now you know the can of worms you opened when you removed tpur thermostart is called “over cooling”
Over cooling is the main reason why you should never remove your your thermostart.
-Apart from missing out that nice warmth from your interior heating, over cooling automatically leads to high fuel consumption this is because for efi engines, on cold temperature the ecu dumps more fuel in the cylinders in oder to bring up the vehicle to operating temperature as quickly as possible, so for as long as the temp gauge reads cold tge ecu will assume the engine needs to warm up quick thus ejecting more fuel the entire trip.( that’d why when you start up the car in the morning the revs go high for a few minutes then come down once the predetermined temp has been reached)
over cooling also has a big impact on engine internals. Too much moisture and production of carbon deposits due to improper combustion means higher chances of corrosivness in the cylinders thus making your engine prone to engine knock anytime
-overlooking alters the viscosity on your engine oil thus making it ineffective for lubrication which in term cases the engine bearing to wear quickly.
VERDICT: Stick to your engine thermostat, replace if it is faulty. This way you will kerp your engine in proper working temperatures which translates to better fuel economy and longer engine life.
Keep it probono thursdays. For our next next episode we shall be talking about coolants and how of importance they are in our cooling system. Until then, be wise choose thermostart.[ATTACH=full]499728[/ATTACH]