How Do I Change the Spark Plugs on My Grand Marquis?
A reader worries about changing spark plugs on a 2004 Grand Marquis. John Paul reveals if the “horror stories’’ about changing spark plugs are true.
Q. I have noticed that Toyota has gone back to the 1950’s, when oil filters, were just the paper part that would fit in a canister that was bolted on the engine. My question is since the paper part costs much less to make than the spin-on filter why do they cost so much?
A. This may be a case of mark-up on the price of the filter. A check on AllData (the database that I use) shows the filter at $5.89. Using the same part number in a search on Amazon has a package of three Toyota filters for $15.95. The website RockAuto has after-market filters that will fit your car with prices that range from $1.95 to $11.00. My cars use the spin-on style filter and I general pay about $5 to $6 each. Perhaps where you are buying filter are inflating the price?
Q. Is there any special procedure to change the spark plugs on a 2004 Grand Marquis? I have heard horror stories about serious problems when you try to change the spark plugs.
A. You are not wrong to worry. Many owners and good technicians get surprised when the spark plug breaks without warning in the cylinder head. Here is what I would try: Leaving the spark plugs in the engine for extended periods are more likely to result in problems. The engine needs to be cool when attempting removal of the plugs. If you can start with a cold engine that was allowed to sit overnight all the better. Loosen the plug no more than 1/4 turn and then spark with carburetor (carbon) cleaner. This will dissolve the carbon and hopefully allow the plug to come out. Tighten and loosen the plug several times, if the plug feels like it is binding stop. If the plug does break Ford has an approved repair method using an insert that doesn’t require cylinder head replacement.
Q. I have a 2004 Cadillac Deville and I am unable to keep air in the tires. They are new tires, brakes and valve stems. This was all done to eliminate the problem. I have had the sensors checked by the tire manufacturer twice and even tried nitrogen – no help. I can’t check tires myself and tire dealer said to bring the car in and they would check the tires for me. It is impossible to go for more than two or three days without adding air. The check tire light is on most of the time and when checked they are usually low. One of the dealers took the tires off the rims, sanded the rims – did not help. I am at a loss as to how to solve this problem.
A. This is fairly common as cars are getting older. The air is most likely leaking out either around the rim or through the rim. Some of these wheels get corroded around the edge where the tire bead seals to the rim. Other wheels actually become porous and leak but sometimes can be repaired by sanding the wheel and using silicone sealant. A permanent repair may be replacing the wheels with a new set.
Q. I heard you on the radio and you mentioned that you drove a Porsche 911 with all wheel drive but was worried about driving it. I never heard why, what was the problem?
A. The Porsche 911, in this case the Targa roof all-wheel drive is a phenomenal car to drive, even during this past winter as long as it has appropriate tires. The problem is that even the snow tires were very low profile and I was concerned about potholes and wheel and tire damage. I did put in a request that once the roads get better I would like a chance for a more thorough road test.
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