I overtightened the Aux Fan Switch and stripped the Block's threads located between spark plugs 1 &3. Cooland in leaking out like mad.
PLEASE HELP!!!
Is there any way to fix this???

 

Have you tried retapping it? HOPEFULLY you won't have to enlarge...

 

Isn't that in the head???

 

The threads are totally gone. I have them in my hand. Do I have to re-tap it? The switch wouldn't fit then. Is the switch/aux fan history?

 

:eek: Sounds like Heli-Coil Time.. I've never used them, but it's a thread repair kit...

 

It would require a pipe thread tap most likely. Those are $$$. I don't think heli-coils are made for pipe threads.

For short term, I would see how small of a temporary freeze plug you could get. They are rubber and compress when you turn the bolt that sandwiches them. It is kinda like a sway-bar bushing sandwich.

You might have to go with a different maker of the fan switch (i.e. Ford or Chrysler). If you luck out, they will have a switch that is relatively the same temp but a larger thread dia.

Good luck. It sounds like bad news. -Matt-

 

Just tap in new threads of the next larger size, then screw in a reducer fitting that will allow the aux switch to screw in to it. Teflon tape the pipe threads but leave the first two or three WITHOUT tape. Be sure to wind the teflon tape in the correct direction too.

Done deal.

Has no negative effect on the fan switch; in fact, I had to do something similar when I installed my Edelbrock heads since the tapped hole in the head was larger that the fitting I was trying to screw in.

Hope this helps.

Jake

 

Take the original bolt/sensor or what ever it was to a place that sells helicoils. A trade auto parts store/macine shop will have them. I doubt a NAPA or pepboys would. Hit the yellow pages and start dialing.

Hopefully they have a repair kit the right size. If they don't find out the size and thread type and start hunting the web for mail order.

Good luck, I know how you must feel. I stripped my crank bolt last weekend. I was lucky and the threads were still there and all I needed to do was to tap it. But it was a pretty losey feeling until it was fixed.

 

Sorry to here about more misfortune! Again I think its my luck rubbing off on ya....

I would try the above mention senerios.

 

Coolant is not a good sign. :nonod: Hopefully you haven't damaged the head too much.

 

you cant use a helicoil in a coolant passage effectively (no way to seal it) --that and I don't even think you can get one that large anyway. I vote for finding another brass fitting that the sensor will thread into and tapping and rethreading that size as stated above.

 

Well, here's what happened. I visited 2 speed shops and Pep Boys, none of which had a tap large enough. There was a guy at the one speed shop that was very helpful. He gave me 2 options. One was to drill and re-tap. He showed me the next larger size, and it would be too big to just tap. It would need to be drilled first. He also had a fitting that would fit the new hole, and had inside threads that would fit the sensor. The other was to seal it with the 2 part bar that you cut and work like clay, then apply, and it hardens like steel. Well, I talked it over with my brother and decided that it couldn't be drilled and tapped on the car. The head would have to come off. So I had to go with option 2 :eek:. I know, I know, but as you can tell, I am in no way a mechanic, and there's no way I would ever attempt that, and there's no one that I know around here that I would trust to do that job. He assured me that the 2 part steel would work, and it said that it would bond to brass and aluminum and it was good to 300* and it resists antifreeze. So that's what I did. I cleaned and dried the area, put a wide bead on the threads that were left and screwed it in to the end, you know the point where stripped bolts come to a good wedged spot :yesnod: , wiped off the excess, then put a healthy bead of the stuff around the sensor, really working it in. It hardened up in about 5 minuts, but I am going to let it cure overnight, so I'm not sure if it worked yet...man I really hope so. If not, the head will have to come off, on second thought, lets not think about that right now, I'd like to get some sleep tonight!!! My brother said that this will buy me some time, but I'm hoping for a perminent fix. We also tested the switch and it's still grounded, so the switch still works...not sure at what temp, but its sure not 200* like MAD advertised. I will post the initial results tomorrow night. As for the future, who knows.
I probably don't want to here 'em, but I'd like to get some opinions/experiences with the steel epoxy. Do you think it will seal it perminatly? Would you consider it "Jerry Rigged"? I do, but if it works...
Oh yea, here's what I think caused the problem. When I compared the MAD switch to the Auto Zone switch, I noticed that the Auto Zone's switch had threads that went to the top pf the sensor, so when it was in, the nut part was flush with the head. On the MAD's sensor, the threads stopped about 1/4" from the nut, and I kept screwing it in until it was flush. That's what caused this mess. Wish I'd of noticed that before I put it in :nonod:.

 

Coolant is fine. The switch goes into a coolant passage in the head. So even if you were changing it out for a new one you would have coolant leaking out.

 

Scorp, what do you think about what I did to the head. Will the steel work? Did I make a mistake by using it? Just curious.

 

It'll probably hold for a while.

Aluminum is supposed to be easy to weld so a patch could be welded and rethreaded once the head is off. If you have a lot of miles on the heads, you could just pull them both, get a used head to replaced the damaged one and then have them both reworked.

 

Hope that holds for ya....It may be fine for a long while.

If not then I guess you will have to go with the same setup as mine :)

Man, I hope you are fine with the way it is. Is is leaking any coolant now? You may be able to get some of that RTV sealant called "The Right Stuff" and smear it around the sensor. Allow it to set up and I bet your leak stops if you have one. The stuff is AWESOME. I will never use regular RTV again. Did the fan ever start coming on?

Let me know.

Jesse

 

I believe that aux fan sw is in the block, just below the left head.

If that steel "bondo" has a similar expansion coeficient and you got the hole clean enough it should hold well.

If not, see if you can get a rethread tap from Sears of the correct size. It might not work but would be worth a try anyway.

Good luck, hope all is well now.

 

No leaks... yet, I put a healthy wide bead on the threads, and "caulked" the nut to the head bigtime! It goes from the top of the nut on the sensor to the head. Rounded it and fanned it at the head. That stuff is like a rock when it dries. I tested it last night for an hour and today at lunch. So far so good, but with the extreme heating and cooling, who knows. The real test would to leave my cell at home and drive to the middle of no where. That's when it'll fail :rolleyes: .

Ski, could I interest you in another weekend job???

I haven't disconnected the main fan to let the car get over 200 so I'm not sure if the Aux Fan is working or not, or what the temp setting is, but I tested the housing and pos batt terminal and its grounded, so that's good. If the fan doesn't go on, I'll pull the connector and see if the center conductor is switching over to ground. If so, then its the connector. If not, its the sensor. I'll let it go to around 240, because I thing that's what the stock sensor is set to come on at. What a PITA this has been, and will be to get it fixed right. :(

 

To test the aux fan circuit pull the connector to the aux fan sw and ground it with the key On. If the fan doean't come on then wring out the wiring through the aux fan relay (on/near the radiator) to the aux fan.

 

65Z01 - I did that, and it kicks right on.