On my '91 N/A, the small sensor (with the wire coming out) on top of my radiator has started to leak bit and there's a small spray of coolant on the fan shroud. My first response to this is to investigate the condition of the sensor and, providing someone can tell me if it's suitable or not, wrap the threads to tighten contact. My question is...can Teflon Thread Tape stand up to the heat and humidity associated with the radiator? Anyone know of other suggestions?

 

all i know is its ive used it for home plumbing purposes. it goes on pipes for cold water as well as hot water. maybe they have a higher temperature tape? dont really know for sure if its supposed to fix leaks i think its just to get the threads on and off easier so they dont rust together..im not tim allen though so...

 

It will stand up to the heat.
Be sure to fix your problem before re-assembly.
It will not seal leaks.

 

my friends 89 developed a crack at the top of the radiator...stupid plastic crap...anyway, we coudln't figure a way to plug it up (since it was stupid plastic crap). he ended up having to get a new radiator when the spray started getting worse.

someone suggested that he should have just gotten a generic radiator to replace it, might have cost less if it didnt have the little spout off to the side for the cap that S5 rads have, like i think S4 radiators are like that. has anyone done that?

 

Easily into the 1000F range - if your rad gets that hot, you'd have to a lot more to worry about than the sensor itself.


-Ted

 

Be careful using Teflon tape on sensor threads. A lot of them ground themselves thru the threads. Teflon tape is non-conductive. You may cause some wierd sensor issues due to a lack of grounding. John

 

I had the same problem and the teflon tape didnt work that good the first time i used it but when i put it on again, i put a little more then the 1st time and it worked great. I dont know about long term use but it lasted right through the summer with out a hitch

 

You can easily use teflon tape on the coolant level sensor (the one you're talking about) it doesn't ground through the threads (since it's installed in plastic). Just make sure it's wrapped around the threads and doesn't end up floating around in your coolant. One other thing to note about that particular sensor is that the sensor itself is subject to breaking where the threads meet the head (under the rubber sealing washer). This happened to me and I couldn't figure out why it wouldn't seal (even after using teflon tape). I looked and found out that the sensor had a crack that was allowing coolant to escape through the body of the sensor itself rather than around the threads (it's very hard to see this crack btw). Mazdatrix sells them for about $14 if you need a new one, or you can get one from a junkyard (if you do this you should get a couple as you can't be sure if they're better than yours).

-W

 

No, You don't want to use teflon tape on anything plastic. It will expand the plastic and eventually cause further leaks, from cracks.

It would be fine when the plastic is brand new and gives very little, but over 10 years old under the hood on a car with day in and day out heat and cooling, the plastic becomes brittle and any additional stress such as forcing the threads wider will eventually cause failure.