coolant temp sensor


tmar04

15+ Year Member

Joined
Oct 16, 2009
Messages
54
Points
3,101
Vehicle Year
1987
Transmission
Automatic
what role does the coolant temp sensor play in engine operation? Is this thing located in the thermostat housing, on left side facing front of veh? I have 87 B2, auto tranny, and when you first start it, idles about 1500 rpm. gradually slows down to 800. takes about 15 min to do this. during this time, tranny will not shift into gear. when idle speed reaches 800, and temp of coolant is normal operating temp, tranny will shift and veh drives off. this sensor has a two wire plastic connector.( temp SENDER ALSO located in thermo housing, but on opposite side. thanks to all.
 
Did you check the oil level once the oil gets hot and expands there is enough to make it go. Thats what happens when mine gets low add about half a quart if it is low but don`t over fill it as far as I know yours does not ave electric shift. The temp sensor just tells the computer the engine temp for adjusting air fuel ratio just add a little oil cold and see if that works you want to check the tranny oil when the engine is hot and running in neutral. Then try a determine where the oil is leaking. mine leaks slowly from the oil pump seal on the torque converter and add a half a quart every two or three months. I keep some behind my seat.
 
I'm with Kim. The coolant temp sensor helps in determining the proper air/fuel ration, which can affect idle speed, but your idle is ok for conditions and should not keep your transmission from going into gear.

Sounds like low fluid to me.
 
My '89 auto is similar. When you start it cold, and I mean even like in the 60 degree range, It hits fast idle at 1500 and If I drive away while it's on fast Idle, the trans won't go into fourth. But I guess that makes sense because fourth is electronically controlled.
 
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