Coolant temp sensor question

[MEZZZ]

Need to replace the coolant head temp sensor. I am thinking I need to drain at least part of the coolant first, correct? Then, my question is, should I use pipe dope around the threads of the new one before installing?

I also bought a new thermostat figuring I might as well do that since I am right there, anything I should know to look out for?

Last question, I am going to pull the valve cover. I bought a new gasket (fel-pro) and it says not to use any gasket sealer on it. Can anyone verify that? Thanks!

[zbane]

You will need to drain some of the coolant from the system before you remove your sensor, but if you don't, it'll drain some of the coolant out when you do remove the sensor. Might as well do it yourself, unless you like having coolant spill all over the front of your engine...

Those sensors can be very stubborn to get out. I'd go ahead and hit it with some pb blaster (or your choice of penetrating lubricant) and let it get to work before you try to force anything.

For reinstalling the sensor, I would use a bit of silicon tape or thread locker (assuming it's meant for use where liquid is present). I don't have any experience with pipe dope, but I would imagine it would work.

If you are going to replace the thermostat, obviously you will need a new gasket. When was the last time the entire thermostat housing was removed from the car?

Since you are going to drain some of the fluid out, why not drain a bit more and remove the entire housing so that you can replace the gasket between the housing and the block?

If you do this, beware that there is a risk of thermostat housing bolts breaking in the block.

Use lubricant and let it sit.

For the valve cover, I would (and have) used just a little bit of gasket sealer on the top side of the gasket, to hold it to the valve cover.

Once you remove your cover and clean it, you will find little grooves on the bottom mating surface. Just put a little bit of liquid gasket (or similar product) in there. It makes it much easier to get the gasket lined up and held in place when you reinstall the cover.

You don't want too much; just enough to hold it in place. You do need to make sure that the gasket remains flat, and doesn't have any gaps. Too much goo can make the surface uneven, even if it looks good to the naked eye.

[blue 72]

zbane pretty much answered it all. Just be especially careful of the rust and corrosion that will likely be on those old bolts, and reinstall them with some Anti-Seize after running a tap through the old threads to clear out any other leftover gunk.

I've just recently installed a new valve cover gasket, but it was a cheapie cork style. I simply coated both sides with Gasgacinch, let it dry to tacky and installed. I haven't had any problem with uncoated valve cover gaskets made of more conventional gasket material though.

[MEZZZ]

Thanks guys, I will heed the advice. I just ran through a bottl of Stabil for the winter a few minutes ago. I havent started it in about a month (been too busy with other things to work on it).

She started right up after about 2 seconds of cranking, smoked a little for about a minute then stopped. I am going to replace the temp sensor per the advice of Sblake01 as it runs great until warm and then starts to miss. Someday I will figure this thing out!

[AZ-240z]

If you replace the thermostat, just be sure to use a NISSAN ORIGINAL EQUIPMENT thermostat from your local Nissan dealer. Aftermarket thermostats have a smaller opening for coolant flow, and I guarantee that your car will run warmer than with a Nissan thermostat.

Been there

Dan

[MEZZZ]

Thanks Dan. I did NOT buy an O.E.m one, so I will go ahead and take your advice as well. I guess I will just pitch this one...wasnt too much $$ and I bought it awhile back, wont be the first time I've thrown away some $$ on this car

Thanks again