Water Temp Sensor

[ramsesosirus]

My stock 76 had a 2 wire water temp sensor in the thermostat housing..

I plan on using the housing from the donor motor, which was from a 78 or 79 z or zx.

Are all of these sensors the same?

I noticed the water temp sensor had 2 wires (1 bullet, 1 ground screw) on my stock one, but the donor one only has the bullet connector, no ground.

Will this work?  Is it internally grounded? 

Thanks

[Zed Head]

14 minutes ago, ramsesosirus said:

I noticed the water temp sensor had 2 wires (1 bullet, 1 ground screw) on my stock one, but the donor one only has the bullet connector, no ground.

I think that's a switch.  For the second magnetic pickup in the distributor and circuit in the ignition module.  The sensor, for the gauge, has one wire, yellow, I think.  It grounds to the housing.

[ramsesosirus]

Thanks for the reply Zed.  Here's some pics.

Stock from 76 280z:  has broken bolt that is stuck in housing where ground went.  The part that threads into the head is still on the other side, but bent and stripped (so I was trying to use the donor engine's Tstat stuff)

Here is the donor engine's tstat gear (engine must have been either a 79 or 80 280zx?  Had an N47 head with diamond exh ports)

This one has a seized bolt in the housing, but is not broken or stripped.  So I was going to try to spin the whole housing into one bolt, silicone it, then insert the other bolt.  There's no way the sensors are unscrewing from either of these housings.... 

[ramsesosirus]

Darn I think the single green wire sensor in the second pic is for the fuel injector fan which the donor motor had.    That would make the donor motor a 79 I believe....

Man I hate rusted, broken bolts.  I'd be ready to start it up if it wasn't for them.

[Zed Head]

You don't really need that second pickup.  Although it does take you through engine warmup more smoothly.  There is a short time during warmup where the extra timing advance keeps idle speed up.  If it's not there the ignition module will just run off of the other one.

I had the same problem with the bolt broken off in the housing.  You might be able to drill it out.  The drill will probably walk off the bolt or through it and in to the aluminum.  Mine did but I reused it anyway.  Some sealant and a good gasket and no problems.

Those are the same.  Coolant temperature sensor.  For the ECU.

The temperature sender (for the gauge) in your top picture just has a bullet connector.  That might be the normal mode.  Not sure and not by my car.

Heat the housing with an air gun or torch.  Aluminum expands a lot more than steel.  Those sensors will probably come out.  Do it while it's on the engine for leverage.  But the holes in the  housings might or might not match what you need.

Edited April 8, 2016 by Zed Head