I have a 2006 Mini Cooper with a CVT transmission with 30,000 miles. Nowhere in the owner’s manual, service manual, their website or on the Internet can I find out how often to change the transmission fluid. Can you tell me?

QUESTION: I have a 2006 Mini Cooper with a CVT transmission with 30,000 miles. Nowhere in the owner’s manual, service manual, their website or on the Internet can I find out how often to change the transmission fluid. Can you tell me? Also, when I’m driving between 55-60 mph, the RPMs go up to 4, and over 60 it goes back down to 3. It just seems that the car is running rough between 55-60. Also if I’m going above 60, and take my foot off the gas, the RPMs go up from 3 to 4. Can you tell me why this would be happening, and what is normal? I bought the car new, and never had any issues with the CVT before.


ANSWER: The transmission fluid is an intricate part of every vehicle. Fluid change intervals vary from manufacturer to manufacturer. There are many factors to consider with fluid changes. Some manufacturers recommend 60,000 to 100,000 changes. At both of my shops we carry all OEM transmission fluids for all manufacturers. As for mileage intervals on most vehicles with light duty service, three years or 36,000 miles. On snow-belt vehicles used for heavy duty service, snow plowing, commercial uses, etc., an annual fluid replacement is recommended. This may seem like overkill, but consider the cost of an automatic transmission replacement at $2,500 on the low side to $3,000 to $4,000-plus. The cost of the fluid change is cheap insurance. The CVT transmission in your car has had its share of problems and anything you can do to help it is worth it.


 


QUESTION: I have a 2003 Jetta Wagon 2L non-turbo, and was told the oil drain plug threads on the pan were stripped. Should I have an oversize plug inserted or do I need to replace the pan? I think the pan is aluminum, but heard there are some hybrid pans – made of steel with aluminum on top, I could use also.


ANSWER: I see a lot of worn and stripped treads on both aluminum and steel oil pans. As for installing an oversized drain plug, it depends on the damage to the pan. To replace the pan is a simple and inexpensive replacement. You need to have the technician look at the pan for his opinion. The majority of stripped oil pan treads is from the drain plug being over tightened. I do replace a lot of oil pan drain plugs and drain plug gaskets as a maintenance, when the drain plug treads show signs of wear.


 


QUESTION: I own a 1998 Mazda 626, four-cylinder, approximately 166,000 miles. The car overall runs great, but it has a problem with the car occasionally stalling and not able to restart for anywhere from 20 minutes to two hours. However after it restarts it runs fine for a while. This happens when the car is stopped at a traffic light, or in line at a drive-through. I take the car to school some 800 miles from my home, but once off the highway anything goes. I once had it happen and had the car towed back to my mechanic, but by the time the car got to him it, of course, started right up. He said for him to figure out what’s wrong it would need to be not starting. I have seen on the Internet that it could be a problem with the fuel delivery system. I’m not sure what that means. Can you give some insight, and will the cost of repair be worth it given the amount of miles on this vehicle?


ANSWER: I have seen many vehicles such as yours and the most common problem ends up being in the distributor, not fuel-related. To verify the lack of spark a simple spark tester is all that is needed. Check with any good parts store for either a new or rebuilt distributor assembly. Before the distributor replacement, make sure there is a lack of spark. The technician can also check the computer for any history codes in memory.


 


QUESTION: I have read your article about changing sparkplugs on cars that claim 100,000 miles in between changes. I own a 2006 Toyota Sienna with approximately 43,000 miles on it. The owner’s manual states to change the spark plugs at 90,000 miles. I called a couple of dealerships and they stand by the manufacturer’s timetable. I have seen sparkplugs that were almost welded to the cylinder heads after 90,000 miles of use. I want to ask you if I should change the sparkplugs on my Sienna at 60,000 miles and disregard what the Toyota mechanics are saying. One even said I could wait until 120,000 miles .


 ANSWER: Let me first say that I still twist wrenches six days a week, and when it comes to sparkplug replacement I have seen more frozen, rotted and broken sparkplugs than I should see. The most common broken and frozen spark pugs are found in the snow-belt area. Any sparkplug that is subject to the weather elements will be affected. The exception is Ford engines, that the sparkplugs break upon removal in the cylinder head and some sparkplug treads just pop out of the head. I have not had any problems with Toyota engines. However, I would still go with the 60,000-mile replacement, not 100,000 miles. Any Ford owner should check with his technician for a sparkplug replacement recommendation. On most late model Ford engines, I like to replace the plugs at 30,000 miles and use plenty of anti-seize compound on the treads.


 


Junior Damato writes weekly about cars. You can send questions to him care of the Old Colony Memorial, 182 Standish Ave., Plymouth, MA 02360.