Q. I own 1994 Mitsubishi Montero with the 3.5 liter V-6 engine. The truck currently has 154,000 miles on it and the maintenance required light is coming on. I have also started to notice a little miss-firing at speeds above 70 miles per hour. I am also concerned about the timing belt, since I don’t know if or when it was changed. What are the mandatory items I should look at for maintenance with this kind of mileage on the truck?

A. Having a 15 year old vehicle with over 150,000 miles the maintenance costs can certainly add up. At this point it would be wise to have a quality repair shop review all of your trucks service records and perform an overall inspection. This inspection will help determine what items need attention and when.  Regarding the timing belt, it should have been replaced at least twice by now along with a host of other maintenance items. If the timing belt breaks the engine will be severely damaged. 
 
Q. I have a 1997 Buick LeSabre and I am getting a strong fuel smell in the passenger compartment when I start the car.  What are possible causes?

A. There are several areas that could cause a fuel leak/smell. Possibilities are a faulty fuel pressure regulator, evaporative purge system or a fuel line leak. One of the best tools to find a fuel smell is an infrared exhaust gas analyzer. These tools are very sensitive to raw gas and make a great detective tool.
 
Q. I have a 2005 PT Cruiser that I bought used from a dealer two years ago. Since the purchase both the front and rear brakes make terrible noise. The brakes are worst when I first start off after the car has been sitting for awhile. The brake pads have been replaced and the drums and rotors have been turned three times. Everything seems okay for a short time then it starts again. Any advice?

A. Since the replacement of the brakes seem to fix the problem at least for a short time, it makes sense the brakes are part of the problem. At this point I would ask the dealer or mechanic to check all the brake mounting hardware. If the brake pads, shoes or calipers are shifting as you apply the brakes it could be the source of the noise. I’m also a bit concerned about the drums and rotors being resurfaced as much as they have been. Also if the car sits for a couple of days at a time, rust could be building up on the brake surfaces causing the noise when you first start out.

Q. I’m a pretty dedicated DIY’er and perform most of the service on my vehicles. What is a good diagnostic scanner? I have a Chrysler 300 and a Ford F150 pick up truck?

A. You can buy a simple code reader for less than $100 that will give you trouble codes. But if you want more information you will need a scanner. Professional technicians will use a variety of scanners, some manufacturer specific others from companies such as Snap-On and OTC. These professional scanners are very expensive with prices that start at several thousand dollars and go up from there.  I have been using a scanner called the Autoxray (www.autoxray.com) for several years and found it to be quite good. The one limiting factor is that it is designed for engine and transmission codes and not ABS or Airbag codes. Although it is my understanding the company has come out with a scanner that does much more and rivals some of the professional quality scanners for less than $750.00

Q. I have a 2001 Ford Explorer 4WD. It makes a fan-like somewhat high pitched noise while driving.  The noise increases in intensity and sound with higher speeds and slows down with the truck.  I just had new brakes pads, ball joints and one rotor fixed and still have the noise, only worse.  I have 198,000 miles.

A. I would have the repair shop look for a faulty wheel bearing. Since this is potentially a safety issue I would try to get it in to be checked as soon as possible.