Car Clinic

How to deal with the following problems?

Seat Snafu

Car Problems The passenger-side air-blade light stays on as the car has a defective cushion bladder which costs $1600 to replace. Is the seat safe for an adult occupant and for a lightweight minor? – Unfortunately you can’t have you cushion bladder replaced on the spot as the replacement bladder needs to be calibrated and programmed into the occupant’s sensing system to work properly. The cushion bladder is designed in such a way that it tells the car whether the seat is occupied, the approximate weight of the occupant and even the position of the occupant as it is part of a pressure-sensing system built into the seat. The computer analyses various information including whether the seatbelt is buckled, car speed, the strength and angle of the impact to decide whether to fire an air bag or not. Considering your car’s defect, you mustn’t seat babies, toddlers or kids shorter than 4 feet nine inches in the seat or anyone who weighs less than 95 pounds. In any case this malfunction should be treated very seriously as the air-bag deployment behavior can be unpredictable. Of course you may ignore the warning light to save some money but ask yourself whether it is worth risking the safety of the passengers.

Quieting a Car

Sometimes drivers complain that their compact cars are a bit loud on the freeway. It is possible to quiet down the noise inside the cabin, but you should understand the cause of that nose. The tires, the mechanical bits and the wind can make noise. The first thing you should do is check the engine, suspension and exhaust. If everything is in order, then the noise comes from the tires and the wind. There are two ways to reduce the cabin noise. The simplest solution to this problem is sound deadening. All budget cars do have sound deadening installed, but only in strategic places. That is why to improve the situation we recommend 3M Sound Deadening Pads that cost only $14 a roll. This stuff is supposed to be used as a shock-absorbing sticker that would soak up all noise-making vibrations. All you need is to cut out patches and stick them to the sheet metal, for example on the firewall or the floor. Some adventurous drivers even remove the inner door panels, carpet and headliner to stick a deadener on the inside of the outer door skin, floor and bottom of the roof panel. Another way to decrease the car noise is to purchase the quieter tires next time your rubber needs changing.

A Filling Question

If the new Mercedes E-class stays parked in the garage for a long time, should it be stored with a full tank or not? - You have two options. If your car has a plastic tank which naturally doesn’t rust you need not worry about it and can either store your car with nearly empty tank having added fuel stabilizer or store it with a full tank with an appropriate amount of fuel stabilizer. You may choose the latter option to reduce the air space in the tank. The problem is that partially empty tanks expose the inside walls and due to daily temperature swings during fall and spring may cause condensation on the tank walls. Because of that there can be some water in the tank that will cause erosion in the long run. This situation is complicated by the fact that now ethanol is standard in the U.S. fuel mix and it is known that ethanol attracts and bonds with water. But if you have a plastic tank you can store it half empty with stabilizer and then fill it up before getting on the road.

Cruise out of Control

What can cause the cruise control of ’93 Jeep Grand Cherokee stop working completely? - At first cruise controls used to be purely mechanical, then vacuum-actuated, and then electromechanical. As your version is electromechanical it means that the throttle pedal is attached to the throttle body with a cable and the cruise control is achieved by way of a servomotor that sucks in the cable and holds it in place. All cruise-control systems are required to use designs that don’t impact throttle control when they break down. As for the potential causes of cruise control failure, make sure to check electrical switches as the contacts may have worn out or become corroded. So you should take them apart and clean to eliminate this possibility. Then check the fuses related to the system and if you have a multimeter be sure to check the wiring from the fuse box to the module. These fixes are quite inexpensive and won’t take too much time. Other fixes are expensive as cruise control modules are known not to last long. Typically the module’s electronics, the plastic gear, the motor and different mechatronic devices become faulty. These spare parts are neither cheap nor easy to replace. If money is tough at the moment and considering the car age, it may make sense to use it as it is.

What is the Deal with Resonators?

Ever wondered what are those nodules jutting off the intake tube running into a car’s throttle body for? In fact, these air cavities called resonators have a very important job. Everything in nature has a resonant frequency and car engines have as well. As engines do vibrate engineering has to deal with how to manage the sound they make. The good news is that resonant frequency can be controlled by changing the volume of an air space. When you turn that extra space the intake makes not loud sounds ( or no sound at all) in the normal rev range of the engine.

Critical Hitting

After a minor side-impact accident when the airbags along the side popped the car door doesn’t close right anymore. Does the car remain safe to drive and is it necessary to make an insurance claim? - Although making an insurance claim is rather a distasteful matter, still it is worth considering. As the airbags have blown there is some metal sheet damage. Moreover, if the door fails to close properly the chances are that the frame has been bent out of shape. In case there is another more serious side-impact accident the car will lack the full protection of the malfunctioning door and airbags also won’t be available. A twisted frame may have an unpredictable effect, including uneven tire wear or even improper handling around corners. To sum it up, you had better submit a claim to the insurance company and get the car fixed to get a safe vehicle to drive and to maintain the car value in case you would like to sell it one day.

Kind of a Clunker

When hitting the gas hard after being at a stop, there is some loud sound coming from the engine bay. Does it mean that there is something wrong with transmission? – The problem is not with transmission but with the engine mount which is typically a rubber bushing inside a metal mounting bracket used to hold both the engine and transmission to the frame and prevent engine vibration. Often these mounts can be fluid-filled to secure better smoothness. When the rubber in these parts wears out the car starts making that clunking noise under hard acceleration. So the recommendation is to replace all engine mounts either yourself if you are versed in underhood repairs or have them replaced by a mechanic.