Does anyone know what the threads are on the Pinto and Zetec temp sensors? Are they interchangeable? I'm looking to replace my one-wire pinto one with a two-wire one as my ECU seems to get an erratic reading without the direct ground path.

If the Zetec won't work, any other options?

Cheers,
Matt.

IIRC the Pinto temp sender is quite small maybe 6mm dia whereas the Zetec sender either screws or clips into the thermostat housing and is about 12-15mm dieameter.
What instruments do you have?

Just another thought, have you used PTFE tape when inserting the sender? this could be causing your problems with insufficient earth to the engine.

The pinto temp sender is 1/8NPT thread. No need for sealing compounds as long as its done up to the correct torque.

Not sure what the zetec is.

Yup daves right 1/8 NPT, i have just put mine from the pinto in the zetec lower thread ok on the plastic thermo house.

Then realised plastic no earth so i've cobbled together and earth lead on a ring terminal.

Anyway so yes there is a 1/8 NPT thread on the series one zetec thermo house, i will have to check and see if that was originally the temp sender though.

I'm sure someone will come along and tel us soon enough.

The top sender on teh Zetec is for Fan/ECU feed. The lower one is for temp guage and is the same thread as the Pinto.

As said earlier, no earth on the Zetec as it is a plastic housing. The Pinto sender in the Pinto engine should be fine as it earths through the engine. A Zetec sender would work with an earth wire but will give a different range so may not match your gauge.

I upgraded to a Zetec over the winter and the Zetec sender reads much too low on my gauge.

Thanks for the answers guys, looks like it will do what I want.

Should have made it clearer, the sensor will be for my megasquirt so I can calibrate it as appropriate. I'll move the gauge sensor to the top hose I expect. The MS manual says you should use a two-wire sensor wherever possible to avoid ground interference problems.

The sensor I had in mind was from the early Zetec as shown here: http://cgi.ebay.co.uk/FORD-ENGINE-MANAGEMENT-TEMPERATURE-SENSOR-55509-BLK-TOP_W0QQitemZ330117519235QQihZ014QQcategoryZ21654QQrdZ1QQssPageNameZWD1VQQcm dZViewItem

It does look like the later one is much fatter.