Currently trying to remove plug in passenger side head between #6 and#8 cylinders for new fan switch. Any idea what size it is? Cannot insert 3/8" extension into it(too big) and 1/4" extension is too small. It has a square head opening. Any ideas on size befor I go look for tools?

 

dunno,thought it was 3/8"?

 

GM uses metric sizing. 3/8 would be around 10 / 11 mm.

Sara Lou

 

http://buy1.snapon.com/catalog/item....re&dir=catalog

 

I ground down a 3/8" extension to fit the plug. Now if I can only get it out. Have sprayed it with PB and letting it sit.

 

IIRC I bought a 10mm from snap on. Good luck to you, I tried to get mine out on the stock motor, and never got it out. I even gave it a shot while the motor was out, no luck. I hope you have more luck than I did.

 

They are hard to get out. In the past I have gotten them out with a chisel. I also have drilled out the center and used an easy out.