My dad's old Impala has a GM Goodwrench crate engine that he bought new about 9 years ago. He's thinking about junking the car, so I'm planning to pull the engine and drop it in my Firebird instead of buying a new engine. The problem is, he drove the car for quite a long time with one of the spark plug wires loose, causing the engine to fire on 7 cylinders. He's hard of hearing so he never noticed it until someone told him about it. Well, my question is, how much damage can be done to the engine in this case? What would I have to do to make sure the engine will be ok?

 

Well, for starters the cylinder that was not firing had alot of fuel soaking into the cylinder washing away the oil... if it was like this for an extended period of time then expect some huge wear on those cylinder walls. It also puts more stress on the other 7 pistons and rods...

 

If you can still start the motor, put a new wire, or fix the one on there, fire it up, and run it for a bit, see if it still misses. If everything sounds good, run a compression test on all of the cylenders. If they are with in 10% of eachother, then it should be good to go.

 

yeah it all depends how long and how hard he was driving the car on 7 because if he was cranking on it it could do some serious damage and get it running and see how it runs and check compression