Repair 7

Catalytic converters use various types of metals to scrub pollutants from a vehicles exhaust before it leaves the tail pipe. Generally, catalytic converters will last the life of a Mercedes 560SL, but some factors, such as using unleaded gasoline or too many fuel additives, can contribute to the premature failure of the catalytic converter.

Loss of Power

A stopped up catalytic converter will cause a sudden loss of power in a Mercedes 560SL. Sometimes catalytic converters break down slowly over time, causing a gradual loss in power, which may not be noticeable to some drivers. If your Mercedes will not accelerate, even if you stomp on the accelerator pedal, have a mechanic take a look at the catalytic converter to see if it is stopped up. If this is the case, the catalytic converter will need to be replaced.

Drop in Fuel Economy

Measure the gas mileage your car is getting, especially since a sudden drop in fuel economy can indicate mechanical problems. A stopped up catalytic converter will cause a significant drop in fuel economy, more than two or three miles per gallon difference.

Engine Problems

A clogged catalytic converter will also cause operating problems with your Mercedes engine. Besides the loss in power, a stopped up catalytic converter can inhibit how quickly a vehicle travels, making it top out at a low speed like an electronic speed governor. The clogged catalytic converter will cause increased back pressure in the exhaust system, which will choke the engine as exhaust gases cannot leave as quickly as they should. If your car runs for a few minutes then stalls out, if you can hear a whistling sound or your cars engine seems to be struggling during acceleration, take a look at the catalytic converter as the potential cause.

Smell

If your 560SLs tailpipe is spewing out a smell similar to rotting eggs, there is a high chance that the catalytic converter is partially clogged. The broken down elements of the catalytic converter emit this rancid smell, which is very noticeable.

An engines piston rings will help keep the engines compression where it should be and prevent oil from going into the cylinders. Piston rings can wear out from the use of poor-quality gasoline, which leads to carbon deposits or engine knock, as well as from the engine overheating.

High Oil Consumption

Broken or worn-out piston rings will lead the engine to burn oil by allowing the oil to leak into the cylinders. If you determine that your vehicles engine needs oil more often than normal, it could indicate worn-out piston rings. Check the cars undercarriage to find out whether you have an oil leak, which could also explain your engines constant need for oil.

White Exhaust

As the engines oil leaks into the cylinders and burns along with the fuel, the vehicles exhaust system will then take the burned oil in the form of smoke all the way through the vehicles tailpipe. When a vehicle first starts up in colder weather, the exhaust will appear white at first. Constant white or gray exhaust---no matter the temperature outdoors nor how long you drive your car---could indicate worn-out piston rings.

Poor Performance

Worn-out piston rings will affect the overall performance of your vehicles engine and emissions system. Worn piston rings not only leak oil---they allow air to pass through, affecting the engines overall compression. A lower engine compression will lead to a decrease in power as well as fuel efficiency. The introduction of burnt oil into the emissions system will also increase the amount of pollutants exiting the vehicles tailpipe, possibly leading to it failing an emissions test.

The fuel pump on a motor vehicle pumps the gasoline through the engine to be ignited and create power. The fuel must pass through a fuel filter to ensure that no contaminants reach the engine. The filter traps large particles of dust and debris, stopping them from affecting the engine.

Start Difficulties

The first sign of a malfunctioning fuel pump filter is difficulty starting the car. The filter will start to block the flow of gasoline into the engine. This is mainly caused by blockage or clogging, but can also occur from a break in the filter or a misinstallation. The problem will escalate over time if untreated, and what began as a difficult start that took several attempts will become a complete inability to start the engine. Once the filter hits this point of damage the only fix is to replace it.

Stalling

A significant indicator of a faulty fuel pump filter is the stalling of the engine during use. The stall will most likely occur on an upward or downward slope (depending on the placement in the car) when the fuel is being pushed through the filter rapidly. The stall happens because of an interrupted or inconstant flow of gasoline and feels much like the car does when running out of gasoline. At this point, however, the fuel pump filter may just need a quick repair or cleaning.

Acceleration

The fuel pump filters earliest indicator of problems manifests as stunted acceleration. If the car starts running sluggishly or unresponsively it will mean the fuel pump is either off alignment or in the beginning stages of a clog. There is a good chance at this point that a simple fuel injector cleaner solution may fix this problem and the vehicle will start running efficiently again.

A camshaft controls the timing of valves on an automobile engine. Lobes on a camshaft, called cams, push on the valves to open the valves. Springs on the valves close the valves. Camshafts ride on thin films of oil on camshaft bearings. A camshaft bearing goes bad, or is "wiped," when oil fails to get to the camshaft bearing. Your vehicle engine will not operate if a camshaft bearing gets wiped. The engine would seize and shut down. Regular maintenance on your vehicle, such as regularly checking the oil, prevents a camshaft from failing.

Popping Noises

A popping noise develops in the engine as a camshaft begins to fail. As the camshaft begins to fail, the timing starts to go bad, which causes the engine to develop a popping noise. This popping or backfire could indicate bad valves or valve springs, or it could be that the camshaft is failing. Mechanic John Hix says that with any engine he can hear whether the engine is not running right. The timing will lead to louder popping noises as the camshaft gets worse.

Poor Gas Mileage

Poor gas mileage will manifest itself as your car loses power and burns more gas. You will find the car burning more gas to get from point A to point B as the camshaft goes bad.

Loss of Performance

The loss of engine performance emerges as the timing deteriorates. The engine power will go way down and your engine timing will be way off. When climbing hills or trying to pass, you will notice the car will have no accelerating power. As soon as this sign manifests itself, you should have the vehicle checked by a mechanic.

Metal in the Oil

A check of the engine oil might reveal flakes. Prior to the shaft wiping, metal parts will come off the lobes of the camshaft. These naturally wear from use. Excessive wear means they need replacement. Metal flakes indicate that metal in the camshaft has contacted the metal of the bearing. The bearing metal is made from a softer metal, hence the term "wiped bearing." The metal from the shaft literally wipes the softer metal from the bearing. These metal fragments will then end up in the lube oil system; when you drain the oil you will notice metal flakes floating in the oil.

The oxygen sensor(s) in a vehicle, simply put, are clever devices that monitor the amount of pollution the vehicle dispels from the exhaust system. Although the function of the oxygen sensor goes far beyond this simplistic definition, its main purpose is to monitor and communicate its information to the computer system in a car. When an oxygen sensor fails, your vehicle may have obvious side-effects such as loss of power and decreased fuel efficiency. However, this is not always the case. If a sensor goes bad and there are no noticeable side effects, ignoring the "check engine" light may be detrimental to the vehicle.

Function

The oxygen sensor is a small wired unit that is placed into the exhaust stream of the combustible engine of a vehicle. Its purpose is to monitor the burned fuel to air ratio, also known as the "lambda ratio." There is a perfect lambda ratio in the exhaust of the combustible engine and when it changes, the sensor is effected and transmits this information to the engine management computer via voltage signals. Less air in the lambda ratio will create more leftover fuel after combustion occurs and this will result in a rich mixture. More leftover fuel will create more pollution to the atmosphere and decrease the fuel efficiency of the vehicle. Excess oxygen and less fuel creates a lean mixture. This will result in more nitrogen oxide pollutants and can damage the engine or other expensive exhaust components. In all cases where an O2 sensor fails in a vehicle, the engine management computer will detect the information or lack of information coming from the sensor and trigger the "check engine" light to illuminate on the dashboard to alert the driver.

History

Professor Walter Nernst developed a gas-tight ceramic electrolyte that became conductive at temperatures above 620 degrees in 1899. Because there was little concern for its use back then, it was redeveloped and ingeniously modified in the 1960s by Robert Bosch. When the Environmental Protection Agency mandated stricter exhaust emissions regulations in the 1970s, the lambda sensor or oxygen sensor was introduced to the combustible engines to monitor emissions. The first vehicle to introduce the oxygen sensor was the Volvo 240 model distributed in California in 1977, which also came equipped with the three-way catalyst. By the early 1980s, most all vehicles were mandated to have catalytic converters and oxygen sensors to monitor exhaust emissions.

Types

There are quite a few different types of oxygen sensor, but their primary objective is the same. The first lambda sensor was developed with a single wire (unheated sensor) that simply transmitted voltage to the engine management computer. The problem was that it needed to reach a certain temperature in order to begin to work. In the interim, it would waste fuel and create more pollution. A three and four wire oxygen sensor was later developed (heated sensor) that brought the sensor up to an operating temperature more quickly and thus reduced pollution and increased fuel efficiency. The older single wire or two-wire vehicles may have only had one sensor to monitor, but nowadays, there are at least two heated sensors per vehicle and in some cases as many as four, which makes locating the bad sensor(s) a bit more challenging. The older vehicles sensor would be located near or in the exhaust manifold (upstream). Some cars were then developed with one after the catalytic converter to monitor the exhaust after it was filtered through the converter (downstream). If the vehicle has split cylinders on the engine with dual manifold and more than one converter, more sensors are integrated into the exhaust system to monitor each bank and each converter.

Benefits

The benefits of the oxygen sensor are simple. The combustible engine will perform better, it will have better fuel efficiency and dispel less pollution. However, if a bad oxygen sensor is not addressed, the long-term effects of its ineffectiveness can cause costly damage to the engine or other expensive exhaust components. The decrease in fuel efficiency on an annual basis alone would easily pay for the sensor replacement.

Identification

The location of the sensor is screwed or bolted into the exhaust system, usually in or near the manifold, and as previously mentioned near or after the catalytic converter. A wire and plug attached to the exterior side of the sensor plugs into a wire harness to communicate via voltage to the computer and heat the sensor up to operating temperature. To locate the sensors, follow the exhaust components from the catalytic converter forward to the front exhaust pipe and you would notice small devices screwed directly into the exhaust pipes with a wire attached to them.

Warning

Some shady mechanics and people have discovered ways to trick the oxygen sensor or simply clean the sensor in order to save money and not have to replace them while attempting to pass an emissions inspection. While cleaning a sensor may have a beneficial result, it may be temporary. Tricking the sensor is futile in the long run. The thing to consider when replacing the oxygen sensor is that something else may have caused it to fail. The lean or rich mixture coming from the exhaust has nothing to do with the sensor. The sensor simply monitors it and informs the computer, which then makes adjustments to create the perfect mix. An engine that needs a tune-up or has a leak in the exhaust system can be leading causes of damaging oxygen sensors and just replacing the sensor may not solve the underlying problem.