The other day driving home (civic, ls-vtec swap) the car overheated, the fan would not turn on.

since then i have tested a number of things.
1) Run the car untill it gets hot, fan does not turn on.
1.5) Car still engages vtec, leading me to believe my coolant temp sensor is still good (i am unsure here)
2) Jumped the Fan, it is fully functional
3) Upper radiator hose is piping hot, while lower hose remains ice cold, even when the guage is reading hot.
4) Jumped the fan again, this time with the car running, and i was able to get the coolant temps much higher than acceptable, even with the fan running. again, the lower hose stayed cold. The fan had no effect on cooling.

Now... my suspicions are that the thermostat has gone bad. However, i am unsure of whether or not my tests have verified if the sensor is still good or not.

Thermostat?

any help would be appreciated, thanks in advance for your time

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gtistile &raquo;</TD></TR><TR><TD CLASS="quote">
3) Upper radiator hose is piping hot, while lower hose remains ice cold, even when the guage is reading hot.
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Sounds like the t-stat is stuck closed.

 

anyone else have any input?

 

Sounds like the thermostat is stuck closed to me too. If your fan temp switch is located in the radiator and the bottom hose is cold then it never got hot enough to kick on the fan.

Neal