Q: I own a 1997 Mitsubishi ES. I bought the car in November 2005. The cylinder head gasket let go, and I am wondering if I should spend the money to have it replaced. Is this a common failure?

Q: I own a 1997 Mitsubishi ES. I bought the car in November 2005. The cylinder head gasket let go, and I am wondering if I should spend the money to have it replaced. Is this a common failure?

A: Failure of cylinder heads and cylinder head gaskets is way too common. The aluminum cylinder heads are not forgiving, and they expand and contact faster than the cast iron blocks found in many vehicles. Contaminated (dirty) antifreeze also contributes to failed head gaskets. The problem with a failed head gasket is the cylinder head may be damaged (warped or cracked); or there might be antifreeze in the oil pan, which causes engine-bearing failure. The car value is worth basically the cost of the repair. Depending on whether the overall condition would warrant the repair, you have to consult with the shop and see if a better option is a replacement used engine. If you go the used engine route, have the timing belt and water pump replaced before the engine goes in.

Q: I own a 2000 Toyota Camry with only 29,000 miles. The check engine light came on, so I had it checked, and the problem was the charcoal canister. My mechanic said he has replaced a lot of them. I contacted Toyota in California; they reimbursed me for the part, but not the installation. My son also owns a Camry, and his check engine light has been on for a year. The car seems to run fine. What is wrong with Toyota cars?

A: The newer the vehicle, the more electronic emission control equipment. There are sensors for almost everything in vehicles produced since 1996. The failure rate on common failure emission related parts such as yours is above average. Your car is more than seven years old. Be happy you collected any money. Some emission parts are covered eight years or 80,000 miles. Certain vehicles and emission parts are covered up to 100,000 miles

Q: I own a 1972 Mustang with the Cleveland 351 cu V/8. The engine will run very hot in a short distance – three to four blocks. I replaced the thermostat and radiator and still have the problem. What am I missing?

A: The most common problem on the old 351 Cleveland V/8s is that the water pump impeller breaks down. Head gasket failure is very rare; however, a hydrocarbon check is a simple test of the vapor exiting the radiator fill with a gas analyzer. For such a short distance of overheating, I would lean toward the water pump. Most speed shops sell high performance water pumps that have a better flow rate than the originals at similar cost.

Q: I own a 1998 BMW 328 with 120,000 miles. All of a sudden, the engine will not stay running unless I keep my foot on the gas pedal. The check engine light has also come on. I had the computer read and was informed the problem was a faulty mass air flow meter. I bought a new mass air meter, and the engine still will not stay running when I take my foot off the gas pedal. I checked for vacuum leaks as another BMW owner suggested. Do you have any ideas?

A: Just because there is a trouble code referring to a sensor or meter, it does not mean the part is bad. The circuit involved needs to be tested in the flow chart indicated. It is true that the mass air flow meter is a common failure part. A more common failure for sudden loss of idle is the idle air control motor located under the throttle body. Whatever the problem, a proper diagnosis needed. For more troubleshooting information, go to Alldata.com and point to the do-it-yourself section.

Q: My grandmother owns a 1997 Ford Contour. The engine will stall when the brakes are applied. The problem never happens in the cold weather, only when the weather is warm or hot. She has taken the car to a couple of shops, and neither could find any problem. Any suggestions would be appreciated.

A: I see many vehicles that have stalling problems like your grandmother’s that do not set a check engine light on. We hook up test equipment, road test the car and observe the test equipment. Here are a few common parts that fail and can cause stalling as you mentioned: lazy idle air control valves; throttle position sensors; egr valves that do not close fully; dirty throttle body and intake runner or manifold; and curb idle speed that is too low.

Q: I recently bought a low mileage 2005 Toyota Camry four-cylinder. When I start the engine cold, the rpm goes up to 2,000 rpm then slowly drops down to the normal 750 rpm. What does the high rmp do to the engine when cold weather hits, and the oil gets thicker? Can the dealer lower the cold high idle speed?

A: All engines are designed to start cold and run at a high idle speed during warm-up. The high idle speed is to allow faster warm-up time and lower emissions, as well as warm up the catalytic converter. As for the oil thickening cold, today’s oils are much better and do not thicken like years gone by. If you had any major oil concerns, full synthetic oil is the best treatment for almost any engine followed by synthetic blend oil.

Q: I own a 2004 GMC Yukon with only 28,000 miles. The truck has been great for many years. Recently, it developed an occasional hesitation from a stop. I had the car tuned up and checked at the dealer. They could not find anything wrong. The hesitation can happen once a day or once a week. The gas mileage has also dropped three to four miles per gallon. Do you have any suggestions?

A: Just replacing parts does not usually fix a problem, unless the replaced part was faulty. Intermittent hesitation with no computer trouble codes can be a challenge to find and repair. The technician will hook up a scan tool and fuel pressure tester, road test the car and observe all the sensor parameters. Fuel pressure is critical, and I have seen a lot of fuel injector problems on GM vehicles, especially trucks. You mentioned a drop in fuel mileage; I would look closely at the oxygen sensors and would consider poor spray pattern fuel injectors.

Junior Damato writes weekly about cars. You can send questions to him care of the Old Colony Memorial, 182 Standish Ave., Plymouth, MA 02360. He can be heard live on WXBR radio 1460, 7-10 a.m. Saturday mornings.