Dear Doctor: I own a 1998 Saturn with 180,000 miles that burns a quart of oil at 500-mile intervals. What is the best way to slow down the oil consumption? -- Paul

Dear Paul: Have a mechanical engine inspection performed and an evaluation of the positive crankcase system. However, it could be attributed to just plain wear and tear. If so, I suggest the use of high-mileage oil with a high viscosity rating, such as 20W40.

Dear Doctor: I own a Chrysler minivan with 26,000 miles. The dealer says the throttle body is dirty and needs to be cleaned or replaced. The price would be $175-plus. Why is this service needed at 26,000 miles? I have owned many vehicles over the years and never heard of this service. Is the dealer just trying to make money on a service that is not needed? -- Jerome

Dear Jerome: Throttle bodies sometimes get carbon and sludge. This can cause stalling, poor performance, binding and sticking pedals and loss of gas mileage. Throttle body cleaning can sometimes be done with removal of the throttle body. A simple spray of carburetor cleaner and wiping it out sometimes works well. At this mileage point, however, I would suggest a second opinion on the service recommended.

Dear Doctor: My owner's manual recommends the use of Mopar products for all services needed. The only place I can find them is at the dealer. Can I use other brands without voiding the warranty? -- Joe

Dear Joe: It bothers me that the owner's manual does not state in bold print that you can use any quality brand product that meets or exceeds its standards. Yes, you can use any non-factory brand fluid, filter, spark plug etc. that meets or exceeds the manual-recommended brand without voiding the warranty.

Dear Doctor: I own the first-generation Honda Odyssey minivan with 110,000 miles. There is clear water vapor accumulating in the spark plug tunnel in the valve cover. This causes the engine to misfire. The Honda people are at a loss. I have to roll a small piece of paper towel to absorb the water. It happens even when there is no rain. Where is the water coming from? John

Dear John: Water vapor will not simply accumulate in the hot spark plug area. I have seen many small cylinder head gasket leaks that are exactly like your complaint. The next time you have to soak up the water, have it tested to see if there is antifreeze present.

Dear Doctor: I own a 1999 Dodge Grand Caravan with only 50,895 miles. There is a clicking sound that speeds up and slows down with vehicle speed. When I apply the brakes, the noise goes away. I am a do-it-yourselfer; any suggestions would be appreciated. Andrew

Dear Andrew: Noises that change with vehicle speed are usually connected to the driveline in some way. In your case it is brake-related. The noise is more than likely from the brake pad actually moving. When you put your foot on the brake pedal, the brake pads have pressure that keeps them from moving. I service a lot of vehicles that have either missing brake hardware (anti-rattle clips), and/or worn brake pad anchor mounts. Another concern is brake rotors that have a poor finish that will cause brake pad movement. This is also true for vehicles with rear drum style brakes with poor finish brake drums.

Dear Doctor: I own a 1968 Ford Torino with only 100,000 miles. It has been a great car for me. My only problem is the trunk support bar broke and the trunk is very heavy to lift and does not stay open. My mechanic has looked online and every place he could think of to find trunk replacement rods. What are my options? Dolores

Dear Dolores: Check with any good local auto body shop for the installation of a simple gas-charged trunk or hood support. We use these in a variety of both hood and trunk installations. The cost varies from $20 to $40 each. The shop will make up a couple of simple mounting brackets for the gas-charged supports and the job is done. Installation time can be two to three hours.

Dear Doctor: I own a 1987 Plymouth. The current tire size is P-185/70R14. I have access to four P-195/75R14 tires that are like new. The local tire dealer said they would fit, even though they are larger. If they do fit, could I just use two on the rear until spring? Ted

Dear Ted: The major difference is the P-195/75R14 will be much taller than the 70-series tire you would be removing. As long as the tire will fit both front and rear with no clearance problems, you will be fine. You cannot just put two on either front or rear, you must have all four tires the same size.

Send questions to: Auto Doctor, 3 Court Circle, Lakeville, MA 02347