'97 12v CTD wow, what a nightmare... I just spent over an hour beating the crap outta my block heater with a BFH and a crow bar. Was like the thing was welded in there!
On top of that, I accidentally over spun the bolt and the backing plate/nut fell off inside the block.
The backing plate was right there at the hole and I got it out but the smaller nut was not to be found. Poked around in there with a magnet but no luck. Seems to have fallen out of reach.

Is there any significant potential of it lodging somewhere and obstructing coolant flow?? Any suggestions for finding and removing it?

And what a cheap *** design! The backing plate seems just about as thick as the nut... could have just threaded the plate and there'd be no tiny nut to fall off inside the engine.
I'm thinking of trying to JB weld the nut to the plate on the new one so that can't happen again...

Also, any reason not to put a bunch of anti-seize on the new one? Just can't believe how hard that was to get out... I was hitting it so hard I was seriously afraid I was going to crack the block!

 

Losing a nut in the engine block can be a big problem. If the nut fell into the block, it might get stuck and block coolant flow. It's best to try and find it with a magnet or a small tool. If you can’t find it, you should take the truck to a mechanic to check if the nut is obstructing anything.

For the new block heater, it’s a good idea to use anti-seize to make it easier to remove in the future. Be careful not to use too much force when installing it, as it could damage the engine.

 

hi
dont loose any sleep over that nut ,

it will sink to bottom of block water jacket and not hurt anything .