Quote:
Originally Posted by Aaran
most thermo's open at 70-85c (i have the qh thermo book which lists them all  , average is around 72/3c )
and yes its a common as muck vw golf mk4 fault with the thermos opening to early, they jsut go sloppy and dont shut fully, shove a new one in and all is done. also the coolant temp sensor can start to fail which can cause the needle to read low (will either be a 2 pin green or 3 pin blue plug on the top rad hose) jsut change them both when the system is empty of antifreeze
had your windows fallen out yet? got to love that fault to! (most reliable car i have ever owned in my life, not lol) |
id buy a new book then, they aint been that low for years, all modern cars run hotter to help emmisions, take a look below not one below 80 deg
http://auto.howstuffworks.com/question248.htm
http://autos.yahoo.com/maintain/repa...ques018_2.html
http://www.ehow.com/how-does_4895412...tats-work.html
http://www.ehow.com/how_2189728_test...hermostat.html
http://www.helium.com/items/1766866-...rmostat?page=2
this is more relevent to the car
http://www.eurocarparts.com/ecp/c/Vo...bada3a48c&TSTA
oooo look 87deg
Thermostat
The thermostat is simply a valve that measures the temperature of the coolant and, if it is hot enough, opens to allow the coolant to flow through the radiator. If the coolant is not hot enough, the flow to the radiator is blocked and fluid is directed to a bypass system that allows the coolant to return directly back to the engine. The bypass system allows the coolant to keep moving through the engine to balance the temperature and avoid hot spots. Because flow to the radiator is blocked, the engine will reach operating temperature sooner and, on a cold day, will allow the heater to begin supplying hot air to the interior more quickly.
Since the 1970s, thermostats have been calibrated to keep the temperature of the coolant above 192 to 195 degrees. Prior to that, 180 degree thermostats were the norm. It was found that if the engine is allowed to run at these hotter temperatures, emissions are reduced, moisture condensation inside the engine is quickly burned off extending engine life, and combustion is more complete which improves fuel economy.
The heart of a thermostat is a sealed copper cup that contains wax and a metal pellet. As the thermostat heats up, the hot wax expands, pushing a piston against spring pressure to open the valve and allow coolant to circulate.
The thermostat is usually located in the front, top part of the engine in a water outlet housing that also serves as the connection point for the upper radiator hose. The thermostat housing attaches to the engine, usually with two bolts and a gasket to seal it against leaks. The gasket is usually made of a heavy paper or a rubber O ring is used. In some applications, there is no gasket or rubber seal. Instead, a thin bead of special silicone sealer is squeezed from a tube to form a seal.
There is a mistaken belief by some people that if they remove the thermostat, they will be able to solve hard to find overheating problems. This couldn't be further from the truth. Removing the thermostat will allow uncontrolled circulation of the coolant throughout the system. It is possible for the coolant to move so fast, that it will not be properly cooled as it races through the radiator, so the engine can run even hotter than before under certain conditions. Other times, the engine will never reach its operating temperature. On computer controlled vehicles, the computer monitors engine temperatures and regulates fuel usage based on that temperature. If the engine never reaches operating temperatures, fuel economy and performance will suffer considerably.