I was wondering if I could solicit some opinions from you. I was driving home from work today (1988 Plymouth Reliant, 106k miles) and something popped from under the hood, and afterward sounded like a loud lack-of-a-muffler-type sound, but from under the hood. So I pulled over and called the tow truck, since hell if I’m gonna try driving without knowing what happened. So the tow truck guy gets there, looks it over (after we figured the dealer I wanted it towed to, closed it’s gates when it was closed…lame, I know), and determines that the spark plug popped out. So he put it back in and tightened it up. He then checked the other 3 spark plugs, and they were all loose as well.
The weird thing is that I took it to a dealer back at the end of May for a tune-up, because we were driving this ancient beast about 450 miles to it’s new home. So the car has had maybe 600 miles of driving since the tune-up. Assuming the tune-up checked the spark plugs (which the tow guy had a tough time believing, though in the past I have been 110% satisfied with the service from this dealer), do you think I should be worried that all four spark plugs got loose after only 600 miles? The tow guy said he personally wouldn’t worry about it, but I have to wonder.
I wouldn’t worry about it as in “will my car blow up while I’m driving?”, but I would be concerned about the quality of service at the dealership. It is NOT normal for spark plugs to work loose under typical road conditions especially in such a short period of time. Clearly, they were not installed properly.
I had a plug eject itself from the block once, but I had to have the plug port relined and retapped before the car was operable again. I wouldn’t be too comfortable with just screwing it back in and driving off without inspecting the plug port for damage (such as stripped threads).
But it sounds to me like someone just forgot to tighten the plugs after changing them. Lame, but not all that outrageous: one time, we got a car back with a plastic football sitting on the exhaust manifold. Boy, did that stink.
If all of your plugs were loose, then it’s very likely that the mechanic at the dealer’s simply failed to tighten them after the installation. The one that came out simply worked loose first.
Drive it a few hundred more miles, then check the plug tightness again to make sure.
I agree, if they were all loose the most likely cause is the mechanic forgetting to tighten them during the tune-up. If you were charged anything by the tow truck operator, I would take the bill back to the dealer and ask them to reimburse you.
I’d like to go with the Dopers suggesting you check all your spark plugs for signs of having been cross threaded. If they don’t look damaged that way, it’s likely the mechanic just forgot to tighten up. Either way, tell the dealership. Base your decision whether to keep using them on how they respond to your complaint. Everyone can make a mistake, after all.
The tow truck guy tightened them all, and he said he didn’t see any problems. At first he thought they were stripped since he had a tough time getting one on, but he did get them all on, and they appeared rather tight. Won’t be using the dealer anymore since we moved out-of-state, but I’ll call them to ask a few questions. Like I said before, that dealer was the best one I’ve ever dealt with, service-wise. Finally, probably won’t be charged anything since I got them through AAA, and I get like two free tows a year.
I don’t think the plug was cross threaded for the following reasons[ul]
[li]It would be very hard / impossible to rethread the plug correctly into a cross threaded hole[/li][li]The chance of being able to torque a cross threaded plug are slim, generaly a cross threaded plug will strip before it reaches final torque[/li][li]The other plugs were also loose. Now while is is possible for someone to cross thread all 4 plugs on a 4 cylinder engine, I don’t think even the dumbest line tech at a dealer is capable of that feat.[/li][/ul]
I think the technician screwed in the plugs by hand, and then got distracted before he had a chance to come back with a socket and tighten them up.
I had this happen in my mom’s 1990 Grand Prix, although in that car, the reason was because the plug was cross-threaded. The ensuing stripped plug hole had to be heli-coiled.