2000 Grand Marquis- Misfiring and stuttering in Drive - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

chevy561 · 11-24-2008, 18:27

My 2000 Grand Marquis has 105,000 miles on it and it started having a small hesitation/misfiring about a month ago so I contacted 3 different local dealers last week and got an estimate on changing the plugs. Man O Man, it ain't like in the old days. I got estimates from 129.95 to 680.00. It turns out the boots on the plugs are a real problem area. Anyway, they scared me into doing the job myself and the car ran great for about 2 hours running errands. Then the thing started doing the same thing only worse. I noticed when I started up the engine one time the oil pressure gauge was jumping up and down and would rest on zero for just a short time and then start jumping again.
The next day I pulled each coil and boot one at a time to check for cracks and reclean them and noticed small amount of water vapor on the outside of the boot. I recleaned them and added a small ring of Permatex weatherstrip glue to the ring that sits down on the head and also a little around the end that meets the coil to seal out any future water vapor. Just to make sure the spring did sit on the plug right, I placed it on the plug first and then dropped the boot down over it and then placed the coil on it. Did all eight pugs this way. Started the car and everything seemed fine. Next day wife drove it and came back home saying the problem was back. What in the world is causing this????? HELP!!

**tbird100636** · 11-27-2008, 20:36

Quote:

Originally Posted by chevy561

My 2000 Grand Marquis has 105,000 miles on it and it started having a small hesitation/misfiring about a month ago so I contacted 3 different local dealers last week and got an estimate on changing the plugs. Man O Man, it ain't like in the old days. I got estimates from 129.95 to 680.00. It turns out the boots on the plugs are a real problem area. Anyway, they scared me into doing the job myself and the car ran great for about 2 hours running errands. Then the thing started doing the same thing only worse. I noticed when I started up the engine one time the oil pressure gauge was jumping up and down and would rest on zero for just a short time and then start jumping again.
The next day I pulled each coil and boot one at a time to check for cracks and reclean them and noticed small amount of water vapor on the outside of the boot. I recleaned them and added a small ring of Permatex weatherstrip glue to the ring that sits down on the head and also a little around the end that meets the coil to seal out any future water vapor. Just to make sure the spring did sit on the plug right, I placed it on the plug first and then dropped the boot down over it and then placed the coil on it. Did all eight pugs this way. Started the car and everything seemed fine. Next day wife drove it and came back home saying the problem was back. What in the world is causing this????? HELP!!

Sounds like you're overdue for a tune-up first and foremost. Next, why did you remove the springs from the coils??? They're supposed to stay in there and not be removed. Worn plugs will cause a misfire. I have heard of spark plugs breaking off in 4.6L's, but have seen a tool kit to remove them without removing the head if this happens. Misfires can be caused by a multitude of different reasons. This is probably why you had the different estimates.

ronnie l · 12-04-2008, 16:44

Quote:

Originally Posted by chevy561

My 2000 Grand Marquis has 105,000 miles on it and it started having a small hesitation/misfiring about a month ago so I contacted 3 different local dealers last week and got an estimate on changing the plugs. Man O Man, it ain't like in the old days. I got estimates from 129.95 to 680.00. It turns out the boots on the plugs are a real problem area. Anyway, they scared me into doing the job myself and the car ran great for about 2 hours running errands. Then the thing started doing the same thing only worse. I noticed when I started up the engine one time the oil pressure gauge was jumping up and down and would rest on zero for just a short time and then start jumping again.
The next day I pulled each coil and boot one at a time to check for cracks and reclean them and noticed small amount of water vapor on the outside of the boot. I recleaned them and added a small ring of Permatex weatherstrip glue to the ring that sits down on the head and also a little around the end that meets the coil to seal out any future water vapor. Just to make sure the spring did sit on the plug right, I placed it on the plug first and then dropped the boot down over it and then placed the coil on it. Did all eight pugs this way. Started the car and everything seemed fine. Next day wife drove it and came back home saying the problem was back. What in the world is causing this????? HELP!!

You may have a bad coil pack it seems I did. You need to get a scan done to see what cylinder is misfiring.