LCT’s resident car doctor, Bryan Baker, has been working on vehicles for most of his life. As a young boy, he started working on cars with his father. Baker has been a professional mechanic for almost 17 years, including three years as a mechanic for the United States Marine Corps.
In 1996, Baker started working on limousines for a local limo service in Huntsville, Ala. It wasn’t long before word got out that there was a local mechanic who was proficient with all types of limousines. Baker currently owns Classic Automotive & Limousine Service Center in Huntsville, Ala., and repairs limousines for at least seven local operators, including Starlight Limousine Service, the 2005 Operator of the Year Award winner for 1-10 Vehicles.
Baker receives numerous e-mail inquiries from LCT readers regarding mechanical problems and he volunteers his time to respond to each and every one of them. Here are a few recent Q-and-A's.
Q: My 1998 120” Lincoln Town Car has an air conditioning problem. The front (driver cab) gets cold air, while in the back, the air is blowing but it’s not cold. What can I do?
A: If you have cold air in the front and not in the rear, there are several things you should check. In the Freon line running to the rear unit, there should be a solenoid valve. It is located in the small, high-pressure line going to the coil. It is round and usually black with two wires coming off of it. Make sure that it’s getting power. If it’s not, it will not open and will release Freon into the rear unit. The next thing to check is the expansion valve. It’s a little gold valve with a head on it the size of a silver dollar. It should be hot or warm to the touch on the line near the solenoid and cold on the other side. If it’s not cold on the side going into the unit, either Freon is not getting to it due to a bad solenoid or a restriction in the hose, or it is plugged with debris. This is fairly common in cars that had a compressor failure in the past. Little pieces of the old compressor will plug it up. Another thing to check is the heater hoses that carry hot water to the unit. If the valve that shuts them off fails to open, you will have heat and cool at the same time and your air will be warm to the feel.
Q: I have a 2001 120” Lincoln stretch and just had the front air conditioning serviced. I was told it was 2 lbs. low on Freon on the air conditioning located under the hood. Is there any other air conditioning service that needs to be done? It doesn't seem to cool as fast as before. I only have 50,000 miles on this vehicle.
A: It sounds to me that they added too much Freon to the car. Believe it or not, too much Freon will cool worse than not enough. I would take it back and have them remove the 2 lbs. they added, and then check the performance.
Q: I have a 1997 Lincoln Town Car stretch. The low voltage light and beeper go off when the lights are on or off inside when I’m cruising or at a stop. What could be causing this?
A: It depends if your car is equipped with a single or a dual alternator. If it is a single, chances are you are using more power than the alternator and battery can put out when you idle, and it takes a while to recharge. If you have a dual set-up, you may have a bad alternator. What happens is, the car is using a tremendous amount of power when running the front fan, the rear fan, the auxiliary cooling fan, the lights, the TV, the DVD, the radio and whatever else is on the car. When the vehicle is driving on the road, the alternator is turning fast, which allows it to put out its maximum output. When the car is idling, especially in gear, the engine slows down, which also slows down the alternator. At this point, the battery is forced to take up the slack until it can’t run any longer and the car dies.
Q: I have two high-mileage Lincoln Town Car stretches. One is a 1999 model and the other one is a 2002. When I start the engines, there is a funny noise similar to the turbo waste gate on some sports cars. The Lincolns don’t always make this noise but I am a bit baffled as to what might be happening.
The second problem is with my 1996 Town Car stretch. It vibrates badly when accelerating between about 16-25 mph and then it's fine. The prop shaft was checked two years ago and two of the center (horseshoe-style) mounts were replaced with smaller (height-wise) ones. This meant the prop wasn’t in the same line as before. We also ran the differential on the wrong oil for a while. Any thoughts on what may be causing this?
A: There is a device called an Idle Speed Controller located on the intake manifold. It is a silver canister bolted to the intake. It contains a spring and the computer cycles it to control the idle speed. I’ve had several of them fail and create a screeching sound when the car starts or shuts down. I would have an assistant crank the car several times and see if you can locate the sound.
As for the vibration you have with the other car, it is a driveshaft issue. I would check the output shaft on the transmission where the shaft goes into it, and see if there is any up and down play. There is a bushing inside the tail shaft that fails on high-mileage cars. I would also remove the shaft and check for any binding in any of the u-joints. This will also cause the vibration you mentioned. I doubt there was any damage done to the rear end, and I don’t think the cause is coming from there. My money is on the driveshaft, the joints or the output shaft.