Temp sensor swap out

[musketeerracing]

Ummm, I know this is a basic question but I searched and found nothing. And I know i should know better, especially where thread sealant is concerned, but.....


...has anyone had a problem swapping the temp sensor on a 1990 NA legacy WITHOUT partially draining the coolant? Can I just swap it out with my finger on the dyke, as it were?

ACP

[vrg3]

You should be able to swap it without draining the coolant, I think. It's fairly close to the top of the cooling system (I think only the IAC valve and throttle body are higher) so coolant won't drain out too fast.

You don't use thread sealant with the sensor. You just have to make sure the mounting surface is clean on both the sensor and the water manifold, and make sure you're using a new annealed copper washer in between them.

I think a 19mm deep-well socket fits properly onto the sensor. I think I also used a u-joint extension to make it easier to reach on my turbo. I don't have a torque spec; I just tightened it until I felt the copper gasket crush.

[musketeerracing]

Ah. Good advice, then. The Haynes manual says to use sealant but in practice I will defer to you that the washer will suffice. Cool. So to speak.

ACP

[Legacy777]

you should use some form of sealant.......or again...that's what I read.....I just used some teflon tape......

[vrg3]

I disagree... the threads are not meant to seal; the gasket is. You wouldn't put Teflon tape on an oil drain plug or a brake line banjo bolt, would you?

The threads are very large and coarse; they're not pipe threads and they're just meant to anchor the sensor in place and provide clamping against the copper gasket.

It probably won't hurt anything to use Teflon tape as long as you apply the tape right, though, I guess.