Help on stripped out plug for temp sensor on head

[robertearl]

We just dropped in a rebuilt 305 in a 1985 El Camino when I noticed that we had not put in the tempature sensor in the left side head. It had a plug with a square hole in it that I could get to from the wheel well but it rounded out when I tired.

I am looking for suggestions. If I drill it out, can you put a pipe thread in the cast iron head for the sensor? Is there another place to put it? This is the first year with a computer and there is another sensor screwed into the thermostat housing. Can I tap into to that one instead.

I have never done a pipe thread before. How far do you run the tap in since it is tapered? Does the tap take care of cutting the proper taper?

Any other suggestions? I really do not want to pull the motor back out unless I have to.

Reb

 

[rwhite692]

You may have an identical NPT port on the head on the opposite side of the engine.

In that case, put a new sensor in over there, run the wire over to it, and just leave the damaged one in place.

Dealing with extracting a frozen sensor or plug, with everything still in the vehicle, can be a huge pain and **** up a huge amount of time.

 

[BillK]

Reb,
You should be able to drill the plug out. it will already have the pipe threads, same as the other head. They get rusted in place pretty good over the years.

If you know anyone that has a welding torch, and knows how to use it . . . you can heat the plug up real fast till it is red hot, then let it cool off completely and they will usually come out by hand after that. Drill a hole in it first so you can use a big easy out.

You could try drilling about a 3/8" hole then use a small file to make the hole square so you can get the end of a 3/8" extension in there. That should get it out too.

The main thing is to not screw it up so bad that someone that has the right tools cant get it out.

You have to use both sensors. One is for the computer and the other is for the temperature gauge or light. You cannot hook them together. They do make a thermostat housing with two holes, you could go that route.

 

[pop pop]

If you don't do too much and screw it up, the worst you'll have to do is take one head off. Much less chance of a permanent screw up that way.

 

[Nhrabill]

Easy enough, Leave it alone make sure no leaks and move on there are several other locations you can use this in my opinion is an easy one. SBC are great for having 1000 ways to do the same thing.

If you don't like that the manifold should have 1 or 2 if it is a 70's 80's motor with stock manifold of course. look on drivers side behind carb just off center.

http://www.jegs.com/i/Mr-Gasket/720/2557/10002/-1?parentProductId=744365

 

[carhunter]

If the plug is mild steel you can weld a bolt to it and use a wrench or socket on the hex head.

 

[carap]

Do not use an EZ-OUT. If it is tight enough to round off the square drive there is no way a 3/8" EZ-OUT will take it out. I make thousands of dollars a year removing broken bolts from equipment. The only time I have ever had luck using an EZ-OUT is if the bolt broke from over torque. Once you break the EZ-OUT off you really have problems. Your best bet is a little heat.