Q. When starting my 2001 Grand Am on cold mornings, I smell a gasoline odor when turning on the heater fan. The odor is strongest during the first 5-10 minutes the engine is running; then it tends to dissipate as the car “warms up.” My mechanic could not find any fuel leaks. Overall I haven’t had any problems with the vehicle for 104,000 miles. If the temperature is mild outside, I don’t smell the fuel odor. Any ideas that you would have as to the cause of this problem would be appreciated.

A. It is possible that when it is cold outside one of the fuel lines is leaking very slightly. Other possibilities are the purge valve (part of the evaporative emissions system), fuel regulator, or the fuel injector is leaking.

If the garage has an infrared exhaust analyzer, this tool makes a great fuel “sniffer” to detect fuel leaks.

Matrix a good deal?

Q. I’m looking for a station wagon and found a 2007 Toyota Matrix. The car has only 4,500 miles on it and the dealer will sell me the car for $12,000. What do you think of the car? Is it a good value?

A. The Toyota Matrix is a great little wagon and should last a long time. The price quoted is several thousand dollars less than the typical (NADA and Kelly Blue Book) book value. This low price makes me a bit suspicious.

Before you buy, I would have it checked out by a competent garage. The low price could indicate some previous damage that may make you think twice about buying the car.

200,000 miles? No sweat

Q. How many miles should the average car last? If I take care of my car should I expect it to go 200,000 miles? Are some cars better than others?

A. Many years ago when I got into the repair business it was not unusual to do a valve job at 25,000 miles and rebuild an engine at 100,000 miles. Cars that went 100,000 without the engines ever being taken apart were the topic of conversations at local drive-ins.

Today almost any car is capable of 200,000 miles or more with, in some cases, just preventative maintenance.

Noisy heater needs fixing

Q. I have a 2008 Ford Taurus and since the weather has been cold and I’ve have been using the heat I hear a weird noise. It can best be described as a hooting and humming noise. I have been back to the dealer, but on that day it wouldn’t make the noise. What do you think the problem is?

A. Ford has issued a technical service bulletin that almost perfectly describes this noise.

Have the dealer look up bulletin number TSB 08-7-1. The noise is caused by air flow past a leaky seal in the heater system.

’99 car has no heat

Q. I have a 1999 Ford Taurus without heat. This problem first cropped up in the fall of 2006. My mechanic replaced the water pump and the heater core. The heat was restored. In October of 2007, the heater stopped working. However, it started working again the following month. Unfortunately, it has stopped working again. My mechanic checked the thermostat and the fluid level, which were both OK. He has told me that he is unsure as to what the problem is now, given the prior repairs. Do you know of any other steps that may be taken to restore the heat? Failing that, are there any portable heaters or defrosters that could be used?

A. There are some basic diagnostic procedures to follow. The first begins with measuring the engine temperature. Also, the temperature at the intake and return of the heater core should be checked. If the heater is getting up to temperature, the problem may be in the air/heater door system.

The other possibility is the heater/cooling system has an air bubble blocking coolant flow. This could be the early sign of a cylinder head gasket leak.

Regarding portable heaters, the type that plug into the cigarette lighter are only capable of producing a limited amount of heat.

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