Pieces of the threads came out with the old sensor. Is there a quick fix that I can do in the car? Or do I have to take out the engine and possibly take the head into a machine shop and have the boss welded up. Some previous mechanic stripped the out of the threads in the head. I am hoping that maybe I can get a helicoil kit and fix it that way, but I'm not sure if that will get the correct readings to the sensor. Looking at previous posts, it looks as though I need a 10x1.0 thread pitch for it, but would I have enough room to drill a bigger hole for the repair kit if I can find one?


BTW-I am working with a 2.0L head if that makes a difference

You could try screwing it in and hope it catches enough threads to hold and make contact...JB weld on the outside may help hold it.

Or

It would require some welding and machine work. It is not a hole cut with a drill bit...it is cut with an end mill and bottoming tap (I think those are the right terms anyway).

the quickest half-@ss method would be "faking" it with 2 resitors hooked up to switch.

R1 for warm up (not sure of the time frame it would have to used, less than 5 minutes I'm guessing until motor is at operating temp and depending on temperature outside)

R2 for normal driving

Brad Anders D-Jet site would have the values you need.

There might be some conductive epoxies you could use that have aluminum particles in them to transfer the heat, but it might take longer than normal.

Another more complex method would to drill out the threads, get a piece of alum. tube, drill and tap for the CHT and press fit the alum. tube into the enlargened hole.

It BARELY catches any threads at all, and I might have finished them off. I kinda wanted to shy away from JB weld just because it would make future replacement even harder. If it is my only solution though.......

I dont really have the means to drop out the motor at this time, as it is my DD!

So I take it that there is NO possibility at using thread repair kits?

i've never tried to repair the threads on the head....as long as there is room to work with, I see no reason why it wouldn't work.....

for a temp solution, how about screwing the CHT in as well as possible and fab'n something that'll hold it in there via the engine sheetmetal??

Using a thread repair kit with the engine installed would be really tricky. Doing it with the tin installed would be nearly impossible. JB Weld would probably keep the CHT from grounding to the head, which wouldn't work at all.

I'd do the two-resistor trick until you can get the engine out to repair it properly. You could even do the one resistor trick and just run it with "hot" settings. It will just run badly until it warms up. You can pretend you're running Webers.

I picked up a product from Permatex called Stripped Thread Repair. It is a bit like JB weld, but it also has a release agent that you put on your bolt threads or whatever. Then you put the 2-part apoxy in the hole and thread in the bolt. Let it set for a few minutes, take out the bolt, let it set in open air for a half hour and you have new threads! It can even handle a little torque! Stuff was just over $10 after tax, got it at my FLAPS. Time to run out in the garage and give it a try! I will let you all know how it turns out. Thank you all for the help.

Here we go again. Seems like it's been all of 2 or 3 weeks since we did this. The connection supplies both temperature and ground. You're NOT gonna get that with any chemical thread repair products. As a temporary measure, or even a permanent one, remove the shroud screw next to the #3 intake runner. Cut the tin away in a 3/8 inch radius, drill the hole and tap it to 10mmx1.0. Be VERY careful to keep the tap perfectly perpendicular to the surface so the sensor will seat properly! Verify the threads on the sensor are clean and in perfect condition. If they're not so good, replace the sensor. Make sure you have the aluminum or copper washer, and it's in good condition as well. Install the sensor and washer and tighten them down. That's where the 2 litre VW busses put the CHT sensor, and it works fine. If you have the tin off, a timesert in the original hole is the way to go. The timesert kit countersinks the insert and provides a good seating surface for the sensor, but you still have to be careful to get it as straight as possible. The Cap'n

I will have to do some hunting for those timeserts. I have used them before, but I dont know where I got them from! No one around here has those 10x1.0 taps that I know of, so I cant do that with the sheet metal hole.