Lost coolant or overflowed coolant means you now have AIR in your system and this can allow your coolant to boil at a lower temperature. The temperature gauge unit in your intake manifold will not react to coolant that is missing instead it will appear your car is at normal or even cool. Your car cooling system has an overflow tank. Temperature sensors for cooling fans should be rated higher than your thermostat open temperature. Air not directed to your radiator core will effect cooling performance. Fully shrouded radiator fans will benefit from rubber FLAPS installed into cut out openings in that shroud. As your fans are operating at lower vehicle speeds it is drawing air through the core, the flaps are installed on the back of the shroud and are larger than the opening. As vehicle speed increases your fan and shroud are now a restriction to air flow. Installing flaps to your shroud or designing a new shroud to incorporate flaps will increase your cooling performance during high speed driving.
When the fluid in the cooling system heats up, it expands, causing the pressure to build up. The cap is the only place where this pressure can escape, so the setting of the spring on the cap determines the maximum pressure in the cooling system. When the pressure reaches 15 psi, the pressure pushes the valve open, allowing coolant to escape from the cooling system. This coolant flows through the overflow tube into the bottom of the overflow tank. This arrangement keeps air out of the system. When the radiator cools back down, a vacuum is created in the cooling system that pulls open another spring loaded valve, sucking water back in from the bottom of the overflow tank to replace the water that was expelled. Under your air dam there is an "air guide" and this is to prevent air from being directed under the car instead of through the intercooler and radiator core. This is just a flexible thin plastic filler from the spoiler to the radiator support. OEM Temperature gauges are not made with evenly space temperature increments. As the temperature gauge moves up its increments of change decreases.
What can effect your Air-Fuel Ratio?
1984-1989 all have the same part numbers for
the gauge temp.sensor
MD00 1380 Switch, Water Temp. w/5 Speed MD01 7918 w/Auto Trans. 1984 has a different cluster, 1985-89 has
the same gauge 1984 MB28 0312 1 GAUGE, Temperature (in the cluster) 1985-1989
How your gauge displays the engine coolant temperature.
1984
1986, the additional spec of 212 degrees was defined.
1987, There's some changes here. What does it mean?
1988
Since 1983, "normal" oil operating temperature is defined.
Heat can come of different areas other than the combustion chamber, take the 8 exhaust manifold studs for example, those are just hot pins sticking in the side to transfer heat from the bulky cast iron exhaust manifold. There is also an EGR passage from the exhaust side of the head passing through the casting over to the intake side.
Mechanical and Electric Fans
