I just had the spark plugs replaced in my Pontiac Grand Prix. How can I check to determine that they were really changed? The wires still have dust undisturbed on them- is this possible or have I been ripped off?
If it were me, I would pull the plugs and inspect them.
It would be very hard to tell with out actually pulling them… The boot will usually protect the plug so well it will look new even when its old… On some cars you can see where the hex attachment is close to the head… Again in some cars they get discollored, on others they dont… I would wager they did the fronts, but maybe not the back which seems to be par for the course when it comes to plug replacments.
You have to pull them and remove at least one of the plugs.
If done very recently they should look new.
There is a simple hand tool to remove the spark plug wires. It looks like a two-pronged fork with the tines bent at a right angle. The wires are removed without disturbing the dust on the boots. So as others have said, the only way to check is to remove at least one plug.
You will have to remove and visually inspect a couple random plugs. If you don’t want to do this yourself, toss a $20 bill at a mechanically inclined friend and have him/her check one front and one back plug at random to see if they are new. Even the back ones aren’t too difficult to replace on this car (3.8L is easier than 3.1L).
For future reference, if you really don’t trust the shop that just did this work, don’t use them again and find one you do trust. If you don’t trust the person or people working on your car, you will never be satisfied with their work and will always be second guessing them.
If you know enough on how to remove and check plugs, why did you get that job done by someone?