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2007 STS
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5 Posts
Discussion Starter #1
Hello all, yesterday, I changed all of the spark plugs in my 2007 STS. Prior to changing them, my car hesitated while accelerating and decelerating. It has 126,000 miles (I purchased at 75K), so I'm overdue on a tune up.

When taking out the plugs 2,4, & 6, the ceramic part of the plug cracked and I believe some of the debris may have fallen into the cylinder in #4. I think this because after I put the new one in, when I removed it, there were small pieces of debris attached to the plug. All of the plugs fit in the cylinder and the ignition coils fit snugly as well. I replaced the coil on #2 because I cracked the housing while screwing it in.

I have had inconsistent results in getting the car to start. Sometimes it does, others it won't turn over. When it does, the runs "hard" and doesn't stay on long.

I don't know for sure it it is #4, but that was the only one that gave me any sort of trouble putting in (it tightened way too quickly the first few times I put it in).

I'm not a mechanic, but I can follow directions pretty well. Anyone have any suggestions to help me out? I can't get the car to a shop because I can't keep it running long enough to drive.
 

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Premium Member
2006 STS V8 AWD, '95 Ford Ranger
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29,073 Posts
Obviously this is a maintenance failure on your part. You need to carefully retrace your steps and find where you made your mistake. You broke or misinstalled something.
 

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2006 STS 1SF N* RWD NAV F55
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705 Posts
Can you tell us, what brand, and what part number plugs you put in ?
Happy Motoring
 

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2007 STS
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5 Posts
Discussion Starter #4
I used AC Delco 41-990 plugs, which are the exact plugs that were already present.

I agree, it is a maintenance error and I've taken out all of the plugs and reseated each twice, but no change.
 

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Premium Member
2006 STS V8 AWD, '95 Ford Ranger
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29,073 Posts
It's possible that pieces of broken spark plug fell into the cylinder and resulted in damage to the valves.
 

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Registered
2007 STS
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5 Posts
Discussion Starter #6
I'm guessing there's probably no way i can get out any of the pieces if they are down there. Is it time to send it to the shop?
 

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2005 STS
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284 Posts
Buy or rent a bora-scope . Milwaukee and others make them. Remove sparkplugs and take a look. In saying, sometimes it starts and others it won't turn over, do you mean it won't crank? If only ceramic pieces went down, not likely anything in there now but powder. One bad cylinder should not stop the car from running. Something else is going on there. My advise, you saying "I'm not a mechanic", I would have it flat bedded to a reputable shop.
 
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