About to Replace my Cylinder Head Temp Sensor

scottb · 02-15-2003, 09:23 PM

Sunday's project is to replace the Cylinder Head Temp Sensor on my 84. I've read the Pelican Tech Article. Is there anything else I need to know? Any other suggestions or ideas to make the project go smoothly and quickly?

Thanks in advance for the help.

Scott

Thomas Owen · 02-16-2003, 04:18 AM

If you have the proper tool it is not a big job at all. Good luck.

ChrisBennet · ChrisBennet's Garage

Scott,
You can make a tool for putting the new one in by cutting a slot in a 14mm box wrench. A flare wrench is too thick. The old one wire sensor is 13mm. Rather than cut up a 13mm wrench, just cut the wire off the old sensor and use a deep socket.
-Chris
P.S. Hey Thomas, what is you avatar? It looks like an RC vehicle of some sort.

Chuck Moreland · 02-16-2003, 07:08 AM

There are pictures and more description of the job in this thread:

Head Temperature Sensor Replacement

scottb · 02-16-2003, 07:36 AM

Thanks for the tips, guys. One question, though. The Pelican article makes it sound like the job can be done without a modified socket or box wrench. I'd prefer not to cut up my tools, if possible. The article says the new sensor can be put in with a needle-nose pliers. True? Not true?

Thanks again for the help.

Scott

Joeaksa · 02-16-2003, 08:23 AM

Scott,

I did it with the help of a loaned modified socket (thanks Thomas) and it was still a beech! Cut the old sensor wire off as short as possible then take the old one out.

I have heard of others using needle nose or hemostats but there was no way that I could even think of using them in my case (I have SSI's and not stock headers) due to room constraints. The "modified" socket was the only way. Go to a pawn shop or swap meet and buy a deep socket that you can grind away on and not feel bad because you will need it!

You and I both have an aviation background and I would rather work on a Mooney's motor than do this mod again! Just no room in that area to work with and you cannot see it either. Do it once and be glad that it hopefully never has to be changed again!

Joe

yelcab1 · 02-16-2003, 08:42 AM

In my case, I cut off the wires, and the sensor broke off in the middle. I was rebuilding anway so it was no big deal. I just took the head to the shop and tell them, zap it out. But, if you are just doing this without taking the engine out, be careful with it. And do use antiseize when you put the new one back.

ricwon · 02-16-2003, 11:16 AM

i replaced the sensor in my car last sunday. i started by prying the two grommets which are on the head and the back tin. i then snipped the wire leading from the sensor and used a 13mm deep socket to remove it. i finger tightened the new sensor into the head a far as i could and then used a needle nosed pliers to tighten it some more. i was able to finish tightening it by getting a 14mm open ended wrench on it. the sensor does not have to be super tight, i think i read about 6 ft/lbs. then you want to tape the wire lead from the new sensor to the old wire in order to draw the new wire into the engine compartment. unplug the old wire and plug in the new wire. the last thing to do is to reinstall the two rubber grommets. use vaseline to lube the edge of the grommet and press back into place. replacing the head sensor cured my car of dying when the car warmed up so i was happy to find out that was the problem and that i was able to fix it myself! thanks to this board and the great tech articles.

ricwon · 02-16-2003, 11:32 AM

i forgot to say that first you will need to jack-up the car and remove the dr. sd rear wheel. the heat exchangers are stock on my car so i didn't have the problem of no room like joe aeksa had with his car with ssi. it's still a tight fit tho.

marcesq · marcesq's Garage

I would NOT trust using needle nose plyers only.

I tried that and could not get a good enough grip. Borrowed a modified deep well from the local 911 wrench.

My 2 cents

Thomas Owen · 02-16-2003, 12:59 PM

Scott - if you want the modified socket I have let me know and I will put it in the mail tomorrow.
Regards,

john walker's workshop · 02-16-2003, 01:18 PM

don't get too carried away when you tighten it, because they can break off, and then you really have a problem.

scottb · 02-16-2003, 01:49 PM

I'm going to try to purchase a cheap 14mm socket and cut it. That seems to be the way to go.

Thanks all, for your advice and counsel.

Wil Ferch · 02-17-2003, 05:33 AM

Careful..it is embedded in the previous answers...but usually the old sensor is 13 mm wrench size and the new one ( 2 wire one , usually) has a 14 mm wrench size...Porsche does it to us again

---Wil Ferch

scottb · 02-17-2003, 06:37 AM

Wil:

It sounds like I can just cut the wire off the old one and use an unmodified 13mm socket to remove it. I'll modify a 14mm to install the new one.

Thanks, all, for responding. I didn't get to the job on Sunday (I spent a big chunk of time installing a new turn signal/high beam switch), so it's at the top of the list for next weekend.

Scott

Joeaksa · 02-17-2003, 06:50 AM

Scott,

How was the turn signal/headlight flasher switch? I need to do one in my car! Brights keep coming on... Any tips or hints to speed it up?

Joe

marcesq · marcesq's Garage

Hey Scott, this goes without saying, but make sure that you dress the inside and outside of the "cut" made in the 14mm deep well socket as the plastic sheath covering the wires will cut very easily.