Block Heater Screw Leaking

I was replacing my radiator and used the block heater to drain the old coolant from the block before refilling with new coolant. It seems like I loosened the hex screw on the block heater too much however, because it takes way too many rotations to get it flush against the wall again—when it is, any new coolant added begins leaking immediately. From my research I think I might have disconnected the screw from the backing?

Can I simply pry out this block heater and replace it with another? Or should I be worried about cracking the block? Also, I have read that there is a difference between factory block heaters and aftermarket. Should I be concerned if it is a factory block heater (harder to replace?). Any trick for getting the old one out? It seems pretty flush and I do not want to pry much for fear of damaging the block.

Thank you for any ideas.

You can replace the block heater with an aftermarket one purchased from an auto parts store with no problem. To remove the old heater, loosen the screw, and then take a punch/screwdriver and a hammer and hit the heater on one side. This will cause the heater to pivot in the hole so it can be grabbed with a pair of pliers and pulled out.


when you go to screw in the hex screw, put a wrap of plumbers teflon tape on the threads, This will give a positive seal and also make the torque down a little softer.

Thanks for the tips. Looks like the butterfly nut holding the screw in place broke in half, luckily I was able to remove it all. $21 and a new block heater later----everything worked great and she’s running fineeee. Enjoy your Saturdays!