sending unit questions

[chevn-up]

Ok, my water temp sending unit is in the thermostat housing. This is a pic of a plug where lots of sbc's have the sender. It is too small for a 3/8", and too large for the 1/4" drive. Can anyone tell me the tool needed to remove this plug, installing the sender in this location, or should I be happy and leave it in the thermo. housing?

 

[chevn-up]

Question #2....... What is this sender, on the passenger side, just in front of the starter?

 

[rich weyand]

The pipe plug on the driver's side head is apparently a 5/16" square drive, which is a common pipe plug size, See here:
http://www.corvetteforum.com/forums...-to-remove-pipe-plug-in-driver-side-head.html

Given the 5/16" female square drive, that is a 3/8" NPT plug. You need to have the right sender for the gauge to work properly. They are matched to the gauges, not the engines. The correct temp sender for 1985 with 3/8" NPT hole is GM #8993146.

BTW, use Silikroil (or second best, PB Blaster) on that pipe plug and let it soak for a couple days before you try to move it.

 

[VAL]

Question #2....... What is this sender, on the passenger side, just in front of the starter?

Knock sensor.

 

[chevn-up]

Thanks Rich. that forum conversation convinced me to leave well enough alone. Like they say, if it works, don't fix it. nuf said.