OK,,Will a heli coil work for the spark plug or is that a temporay fix? For a Northstar 2001 Deville.

 

O.K. first of all how bad is the spark plug hole stripped? If it will start and then bind up or something close to that, then i would suggest you try a spark plug tap, i have seen them at the local parts store in the tool section. You can try that the threads may be just a bit "boogered" up and the the tap will clean them up. If the spark plug will go all the way into the hole and not tighten then pretty much you don't have a realiable option, a heli coil is a temporary fix at best. The cylinder is under quite a bit of pressure especially during the combustion soo chances are the heli coil will not hold very long if at all. So in that case you are looking a new/reman/used head. Hopefully the first option will work for you. Anymore question please ask. Also with option a the head does not have to be removed to tap out the hole, after you are done tapping it out take a blow gun and blow out the cylinder and use some anti sieze on the spark plugs. Also try to hold the tap at the right angle. you can usually see it try to start how the threads are already tapped. but try to hold at the right angle. I have done this several times, including on cars that I have bought and repaired with no problems.

 

OK,,Here is the whole thing. Seems cadillac engines(and prob all others) has a problem with coolent. It can corrode the engine and then leak. That is what has happened on mine. The mechanic said it went into the cylinder and built up pressure and blew the plug out. Then the rod bent. Now I will need to get a new(used) engine with @42,000 miles and a 12 month warrenty on the engine and labor. He has been told car owners should change anti freeze every 1-2 years. This also happened to my wifes Toyota 4 runner.

 

Yes the 24 month coolant change is the conventional wisdom these days, only learned the hard way after failures like you experienced.