Repairs, spark plugs

So, let me preface this by saying that I don’t know much at all about cars …

In December 2007, I purchased a 1992 Chevrolet Lumina (6 cylinders, 3.1 L engine) with about 185,000 miles on it from a mechanic and friend of the family for $1,200. I’ve put about 6,000 miles on it and about $1,000 worth of work into it between then and now. Some of the work has been for routine maintenance; but most of it has been for other problems, most recently including about $700 put toward fixing a bad coolant leak: first attributed to a loose plug somewhere (~$150), then thought to be due to a loose radiator cap (~$100), and finally found to be due to the heating coil (~$450) when I noticed excess condensation and searched Google for possible causes.

No less than a week since getting the coolant leak taken care of, the car starts making an awful noise on the interstate one night. I call a friend to check it out and tell me whether or not it needs to be towed. He tells me that it’s just a spark plug and that the car should be safe to drive a few miles back to the mechanic’s shop, as well as that a few other spark plugs seem to be loose (one loose enough that he cuts himself trying to tighten it on the spot). The next day, I hear back from the mechanic that the spark plug ?blew out? of the socket, and that to fix it could be between about $200 (in the case that it can be fitted back into the socket without ?removing the head?) and $1,200 (?removing the head?).

Now, what I’d like to know:

Is it worth fixing? The car seems to have no other problems worthy of note.

Why might this have happened? According to one source [], it seems like this could be more than likely the mechanic’s fault; which brings me to a further question,

Should I let this mechanic do the work on it?

You don’t need a new car. You need a new mechanic.

A heater core leak in a 17 year old vehicle would not be unusual or an indication that the car was shot. That’s normal wear and tear. He should have found that easily before changing the radiator cap ($100? After he had already “fixed” it? Yikes). For $150 I hope he at least put in new plugs…sounds like he simply tightened the old ones…too much.

Reading the rest of it, I’ll bet the plug blew out because he overtightened them and stripped the threads.

Repair it may require a helicoil installation. I’d be reluctant to let him do it.

sounds like he simply tightened the old ones…too much.
Or never tightened them and left them finger tight. It can happen, I have done it.