Propper tap -n-die proceedure...installing a temp guage
 

Well...I'm fond of having extra guages. It's like getting a second opinion when your doctor tells you you're about to die. So no vehicle of mine is without at least two oil psi guages and water temp guages. Every now and then I add another, buit it's always at least those two.

So here's the deal here. I wanted to install a temp guage but, after scowering the engine bay for a sutable local, I couldn't find a place to mount the sensor. The BEST position was located on top of the engine block, on the upper radiator hose:

http://www.performancescene.net/foru...p?postid=27837

This position would tell me how hot the water was before entering the radiator for cooling...as opposed to the oppasite read by the stock sensor.

Problem was that the hole was too small for the sensor. I thought I had this fixed by finding a compatible (.21% difference in signal) sensor, but the new sensor was metirc fine-threaded (don't know size exactly). The plug it's self was 1/8 - 18 I believe...but I could be wrong. Not that it mattered because I couldn't fit my sensor in it. So what I had to do is drill out the bung and tap it to bit an adaptor I found for my sensor.

The adaptor I found is a standard 1/4 - 18 Pipe thread brass fitting and is included with almost every oil psi or water temp sensor sold...I have about 11 of them from past installs.

So here's what I had:

http://www.performancescene.net/foru...p?postid=27844

From left to right: Locktite thread sealer with teflon, drill with 7/16 bit, sensor to 1/4 -18 pipe thread adaptor, temp sensor, 9/16~1/2~12mm wrenches.

First I had to remove the upper radiator hose. I highly advise that you remove pressure from the system before doing this if you've driven the car recently. After I got the hose off the aliminum housing I stuffed a rag down it to prvent debris from entering the cooling system. Ideal method would be to remove the housing completely.

I then proceeded to carefully and slowly drill through the housing. Drill straight down, using the plug hole as a pilot.

http://www.performancescene.net/foru...p?postid=27836

After I got the hole drilled through I used a vacuum cleaner to clean the majoraty of the debris out of and around the housing. I then started to tap it. Tapping a hole can be either very difficult or very easy, depending on material and the tap's condition. My tap was a brand new one (as mentioned, 7/16 - 18 pipe thread) purchased from NAPA for $7.

Insert the tap into your drilled pilot and turn by hand until it binds. Proceedimg from here is the most difficult part of any tap job. After the tap catches the aluminum you must apply strong pressure to it, straight down into the pilot, and turn it with a wrench. After a rotation or two the tap will continue easily by easy turning.

http://www.performancescene.net/foru...p?postid=27843

Be sure to back the tap out every full rotation and clean it of debris and make sure that the threads are cutting propperly (the first few threads will be ugly, so don't let that bother you).

After the bung is threaded and set propperly, clean as much debris up as possible. When I pulled the rag out it came out with a lot of shavings clinging to it. I'm sure none got past it inot the system but I'll be flushing it this weekend just in case.

Now that the hole was tapped I prepped my sensor and adaptor by coating them liberally with thread sealer and screwing the sensor into the adaptor. I then threaded the adaptor into the fresh sensor bung. Sealed up nicely.

http://www.performancescene.net/foru...p?postid=27842

Then, after wiring up my guage and hooking the signal wire up to it I got this...

http://www.performancescene.net/foru...p?postid=27840


...stay tuned for an oil psi guage similar type thing and possibly an a/f guage write-up if I can't find a useful guage to put there...

(I, nor the forums, take any responsibillity for your actions. If you attempt this and break something...we're truely sorry...but that's it...)

IIRC there's a technical write up section within Pelican parts. Nice write up by the way. You may want to see about postiing it there as well.

Hope it helps.

Found it

www.pelicanparts.com/944/944tech_articles.htm

Nice write up..... but you do know that was the bleeder screw location you just tapped through?

Yup...I researched what I was drilling through prior to doing it. I modified the brass fitting (small grove on side) to do the same thing. Thanks for pointing it out, though...it's not something I thought to mention.

Just an update...

The place I installed the new sensor is pretty unconventional. What happened is now I get a semi accurate reading from the stock guage and an accurate reading from the aftermarket one...thing is they read at oppasite ends of the cooling system. The stock guage reads radiator temps, and the new one reads block temps. I get almost 40* difference in them sometimes.