Engine Surging: How To Troubleshoot And Repair

Engine Surging: How To Troubleshoot And Repair

Regardless of whether you are a gear head or not, when you own a car, you must pay attention to its well-being. A car is a big investment and it would be foolish to let it break down due to negligence. Many problems can affect this complicated and delicate component. An engine will often come down with issues, and engine surging is a rather common one. Read on to learn its symptoms and fixes.

A common and annoying malfunction most car owners experience is engine surging. When you know which buttons to press, fixing this issue is a 45-minutes-and-under kind of job.

The internal combustion engine functions only when a bunch of parts works in tandem, including spark timing, fuel/air mixture, and exhaust management. The slightest error in any of these parts will deviate the engine from its regular, optimal activities. Naturally, engine performance will be reduced.

This problem is generally referred to as engine surging, otherwise termed deceleration cycles or rapid acceleration. Engine surging can happen when the vehicle is idle or being driven.

The good news, however, is that in many of these cases, you can repair engine surges with minimal costs. Learn the reasons, and how to diagnose and repair this common engine issue in under an hour!

What Are Car Surges?

The average driver might not understand much about the complexities of an engine misfire or surge. If the idle speed of the engine is decreasing or increasing but not staying constant, that is called surging. This is why the best way to understand the dynamics behind an engine surge, you must have a little knowledge about the working inside an engine.

Generally speaking, three things are done by the car ignition system to create ignition: burn, blend, and spark.

Engine Surging

Firstly, the engine burns the fuel your car has. Next, oxygen is mixed into the fuel before being passed through the cylinders. Lastly, sparks are created inside the engine when the fuel mixture travels through the pistons. This process is continuous and grants your vehicle the power to move ahead.

If any of these steps are not followed in the right order or timely, a misfire takes place. Although your engine will not stop working due to an engine surge, it can surely impact the fuel economy negatively. Moreover, the emissions volume is significantly higher than before. When these misfires occur more frequently, these effects add up and do more damage to the car.

Symptoms Of Engine Surging

Your engine will give you a few signs when it starts surging. Apart from the involuntary fall and rise in idle speed, these are the symptoms to keep an eye out for:

Engine Surging: Misfiring

Engine surging varies from a no-start or difficult start situation. An engine that is exhibiting rough idling, stalling or knocking isn’t exactly surging. Engine surging is such a case where the engine easily starts and accelerates nicely at a steady velocity, but after a while, misfires.

Misfiring occurs when a cylinder within the combustion cycle of the car fails. As an engine is equipped with 4 cylinders, the vehicle would continue running even if a cylinder fails.

But, misfiring and surging speed both make the engine jerk, run rough, or buck. In case you are experiencing either, perform some troubleshooting before consulting with a mechanic.

Some cases are so minor that you can repair them in your garage using a few tools. Meanwhile, complicated cases require the workings of a certified professional.

Engine Surging: Check Engine Light On

No matter what the reason, if the engine is surging or misfiring, error codes will be displayed by the OBD-II diagnostics system. As a result, the Check Engine Light will illuminate the dashboard.

Engine Surging: Causes & Troubleshooting

Below we have mentioned a few of the common reasons behind engine surging. While a few of these are cheap and simple DIY maintenance, a professional’s help will be required to fix the others.

Engine Surging: Adjustment Of The Electronic Control Module

The Electronic Control Module is the over-sensitive friend we all have. All of the parameters in the engine are controlled under a specific set of instructions, and if any of them deviate from what the ECM expects, the component responds by adjusting spark plug timing, fuel injection, and air intake to take it back to equilibrium.

Engine Surging: Vacuum Leaks

Vacuum leaks generally take place in hoses, and since these parts are situated under the hood and exposed to heat for prolonged periods, they are prone to wear and tear.

On engines featuring either a Manifold Air Pressure (MAP) or Mass Air Flow (MAF) sensors, vacuum leaks can result in car surging. If the engine surges when you are driving, it depends on the kind of fuel injection your car has.

Engine Surging

An internal ignition engine requires a blend of fuel and air to make combustion. A MAF system calculates the volume of air moving through the throttle body of the engine and uses that information to decide how much fuel has to be injected. Vacuum leaks in these systems will generally create rough idling, but not cause engine surging during the cruise.

On the other hand, MAP systems infer airflow from the internal air pressure of the intake manifold. A vacuum leak in these systems can result in engine surging when cruising.

The solution: Inspect and change the vacuum lines as needed.

Engine Surging: Poor Gasoline

The gasoline oxidizes after spending a little time contained; it’s a natural process. The gas reacts with oxygen to form water, carbon dioxide, and pollutants such as loose carbon molecules and nitric oxides, losing their vigor.

Simply stated, oxidized gasoline contains (is polluted) air. Once bad gasoline enters the engine, the Electronic Control Module marks it as too much air in the fuel or a “lean burn.” A blend too rich or too lean is not good for the engine, as an ignition engine strictly calls for a fixed air to fuel ratio to work.

In an attempt to fix the situation, the ECM injects more bad gasoline into the engine to rebalance the ratio of air-fuel. This causes a decrease in flame within the combustion chambers of the engine.

When the flame decreases, it reduces the pace of fuel injection, running lean again, and then overcompensating. The cycle repeats over and over again. Engine surging and stalling are caused when the engine burns lean and overcompensates for too long.

The solution: Take out the tank and bleed the bad gasoline through a garden hose. Refill the clean tank.

Engine Surging: EGR Valve Stuck

The Exhaust Gas Recirculation (EGR) valve plays a crucial role in the emissions system of a vehicle. It recirculates the combustion chamber’s exhaust to combust again instead of moving it to the emission system, thus decreasing emissions.

During each of the engine’s cycles, the EGR valve closes and opens. If the valve gets stuck in an open position, the exhaust gas moves back to the chamber even if it’s not supposed to.

The engine fails to function when there is an excess of carbon dioxide mixed with the exhaust gas and not enough oxygen. At this point, the Electronic Control Module overcompensates by allowing excess air to enter the chamber through the intake manifold and the engine runs lean. Therefore, the engine surges.

The solution: Change the EGR valve.

Engine Surging: Poor Electronic Control Module

We mentioned before that the Electronic Control Module manages the functions of many parts in the car to make sure the engine is getting what it needs to run optimally. It will also compensate if there is a deflection.

Engine Surging

When the ECM goes bad due to any reason, its tasks are not performed properly. For example, it can inject excess fuel into the ignition chamber for no reason, causing an engine surge.

The solution: This is usually not a do-it-yourself job. Get a mechanic to check the Electronic Control Module and repair it as needed.

Engine Surging: Blocked Fuel Filter

The fuel injectors in an engine feature super-fine mesh filters. The smallest particles can clog them. A blocked fuel filter reduces fuel pressure, forcing the ECM to widen the fuel injectors’ entrance to regulate the fixed amount of flow.

When the fuel filters are forcefully opened, the fuel pressure spikes, injecting more fuel into the car’s engine – much more than it requires. You experience engine surging during this.

After that the ECM shuts off the injectors, creating a fuel pressure drop. Repeated engine surges as a result of continual injector opening-closing.

The solution: You can replace fuel filters quite easily by yourself.

Engine Surging: Engine Running Too Hot

There can be many answers to why an engine is running too hot, but the two most common reasons include air bubbles contaminating the cooling system and low coolant levels.

In the event of an overheated engine, the head gaskets just might blow, causing the coolant to seep out and pull in air. The situation is quite similar to what your car would experience when it is running on bad gas as excess air enters the engine and makes it surge.

The solution: Inspect and refill the coolant within the cooling system. You can flush a cooling system by yourself.

Engine Surging: Low Pressure In Fuel Pressure Regulators

If the fuel pressure regulator starts working at low pressure or the fuel pump fails, the fuel system can experience an incorrect fuel pressure or fuel volume.

As mentioned above, if fuel pressure decreases or the engine runs lean, these changes will cause episodes of engine surging.

The solution: This is not a DIY job fit for amateurs. First, inspect the fuel pressure using a fuel pressure gauge. Take the vehicle to a mechanic if the reading is low. You may have to replace or repair the fuel pressure regulator.

Engine Surging: Incorrect Ignition Timing

A spark is what lights (literally) the way for the fuel and air mixture to combust within the engine’s combustion chamber. The spark plugs send an electrical signal at a fixed time from the ignition coil to make a spark that lights the fuel-air mixture.

The ignition’s timing has to be accurate. If it goes wrong, the fuel and air ratio will not burn properly and the combustion process will not yield the greatest results.

Key ignition timing

For example, if the spark goes off after too long or is too early, the air-fuel mixture will combust too easily. This leads to an overheating engine. Engine surging is common in an overheated engine.

The solution: Get a professional to fix the ignition timing.

Engine Surging: Weak Spark From The Ignition System

Many possible issues with the ignition system can be weakening the ignition spark in your car. A few reasons are the faulty, rotor, distributor cap, wires, coil packs, and spark plugs.

Weak combustion does not give enough power to the engine and the cylinder cannot contribute fully to the crankshaft. Unburned fuel remains on the bottom, which will deteriorate the spark plugs. The car experiences loss of power at this stage, consequently increasing the demand for combustion. Engine surges happen when the Electronic Control Module is overcompensated.

The solution: Weak sparks are a problem you can easily diagnose and repair in your garage. Inspect and change the rotor, distributor cap, spark plugs, and ignition wires. Otherwise, look for poor coil packs.

Engine Surging: Bad Catalytic Converters

Catalytic converters are tasked with replacing toxic fumes, like carbon monoxide and nitric oxide with comparatively less toxic ones. Modern-day cars have catalytic converters.

Exhaust Catalytic Converter Performance

A degraded or broken catalytic converter can translate to a loss of power. Your engine will start delaying while accelerating. A vacuum gauge can be used to check on catalytic converters, or you can use a backpressure gauge or an infrared thermometer.

The solution: Do not try to repair or replace catalytic converters on your own as they are tricky to handle. Have a mechanic take a look at them and decide on the best course of action.

Engine Surging: Damaged Cylinder Walls

Sneezing or popping sounds are created from a misfiring engine. Sometimes, a distinct smell will fill your senses – it’s a mixture of coolant, gasoline, and steam. Such a pungent odor is a sign that the cylinder walls are damaged.

The solution: Bring your vehicle to a mechanic to check the engine.

Engine Surging At Low RPM

Your vehicle may start vibrating or shaking at low RPMs, which is another symptom of surging. Two cases related to surging can be experienced at low RPM. The more common case is when the vehicle starts surging in an idle state. In the second state, a low RPM will result in surging.

Additionally, you will hear odd sounds from the engine.

What Is Low RPM?

RPM or Revolutions Per Minute goes up when the engine runs at high speed. In comparison, RPM falls when the engine runs at lower speeds. In the majority of meters, 1X is used to denote 1000 revolutions.

This is why the RPM meter is measured on a scale of 1 to 10. Typically, a car must show 1000 as an idle RPM rate. It can also be 800 RPM for some cars. The RPM of the engine fluctuates proportionately with the car’s speed.

Idle vehicles that show RPM rates under 600 are known as low RPM vehicles. The Idle Air Control or IAC valve is responsible to keep the idle speed of the engine constant.

Reasons For Engine Surging At Low Speeds

1. Idle Air Control Valve

Engine surging at low RPM could signal a poor IAC valve. As IAC controls the air intake required to power the engine, a problem with this component negatively affects the combustion within the engine. The IAC can be found close to the air intake compartment and the car’s computer controls it.

The IAC is adjusted by this computer to regulate the idle speed. While performing this adjustment, many dimensions are taken into account like electrical system load, engine temperature, throttle position, and air temperature.

When the car accelerates, the IAC lets in more airflow and it blends with the air and fuel. Subsequently, the RPM drops and results in surging. It might lead to a poor IAC valve situation, blockage, or complete malfunction.

A qualified mechanic or a vehicle diagnostic computer system could troubleshoot it. Changing the IAC valve seems to be the sole solution to this issue as clogs make it impossible to repair.

2. Fuel Injectors

After the air is properly mixed with the gasoline, the fuel injectors do their job of injecting fuel into the piston cylinder. A proper blend of fuel and air injection creates a full blast powered by the spark plugs. Thus, injectors are vital.

Clogged or faulty injectors fail to inject the air-fuel mixture timely and properly in the piston chamber. The result? The RPM falls and eventually, it leads to surging. Furthermore, it can cause excessive fuel consumption as a lot of the mixture is wasted in injection. It can create a lack of power, ignition, and low RPM while throttling.

Leave the repairs and replacements to a mechanic in this case.

3. Fuel Pump

The fuel pump takes in gasoline from the tank before sending it to the mixing chamber. As your car operates, clogs may form in the fuel pump and it will sustain regular wear and tear. Don’t expect it to last forever.

A malfunctioning fuel pump can interfere with appropriate fuel mixing, resulting in surging and low RPM. For best operation, the fuel pump should be cleaned and reinstalled.

4. Fuel Filters

The fuel filter is a component that cleanses the gasoline for contaminants before it is combined. Nevertheless, a fuel filter can get clogged with time, resulting in interrupted fuel delivery.

This is one of the key causes of car surges. It may also result in difficulty starting the engine and, on rare occasions, a misfire. Usually, replacing a fuel filter might help the reason.

5. Engine Sensors

A computer uses multiple sensors to ensure appropriate fuel mixing. The temperature sensor, for example, monitors the temperature of the engine. To start the car, a cold engine requires a thick mixture, but a warm engine needs regular mixing.

A malfunctioning temperature sensor might cause the car’s computer to create the incorrect engine mixture. Low RPM and surging might result from this poor composition. The air sensor monitors the quantity of air incorporated in the air-fuel mixture once again. The computer then produces the appropriate air mixture based on it.

More gasoline will be utilized if this sensor fails. It will cause low RPM and surging. Replacing the bad sensors should fix the situation.

6. Spark Plug

This critical component of the motor ignites the fuel at the optimal timing for optimum power output. Carbon buildup at the tips of spark plugs over time can result in a poor spark.

A defective spark plug can lead to excess fuel use, trouble starting as well as surging. A professional can determine if it should be cleaned or replaced.

Is It Safe To Drive When An Engine Misfires?

Typically, the car can continue to operate if one cylinder misfires as the remaining ones will power the car. However, don’t expect your vehicle to run properly. Chances are, the situation will worsen with time.

Avoiding the issue for an extended period might cause harm to engine components such as the oxygen sensor and catalytic converter. Consider the safety issue if the vehicle loses power and comes to a stop amid a packed road. Misfiring engines don’t have good fuel efficiency and consume more gasoline.

Cost To Fix Misfiring Engine

If you’re lucky, you can perform a simple spark plug replacement in your garage for a few dollars. Other times, a major replacement will set you back a few hundred to a thousand dollars. The fuel injection system may need replacement and counting the cost of parts and cost of labor, the total bill will be about $300 to over $1,000.

Engine Surge: Facts You Need to Know

  1. Engine surge is when your car speeds up and slows down even when you keep the accelerator steady.
  2. The problem may come from a faulty sensor or system that is making the computer deliver too much or too little fuel and then try to correct the fault by over-compensating.
  3. Components or systems that can cause engine surge include vacuum leaks, fuel injectors, emission control systems, fuel pumps, fuel pressure regulators, air filters, and PCV systems.
  4. Paying attention to systems in need of maintenance can help fix engine surge.
  5. Diagnostic trouble codes can point you to the source of engine surge, even if the check engine light is not on.
  6. Vacuum leaks are a common cause of engine surge, especially on vehicles equipped with MAP or MAF sensors.
  7. A faulty idle speed control (ISC) motor or idle air control (IAC) motor may cause the engine to surge at idle or low speeds.
  8. Problems with components in the ignition system may also cause engine surge.
  9. Other potential sources of engine surge include transmission problems, catalytic converter issues, and neutral position sensor faults.
  10. Engine surge is a safety issue that needs to be addressed as soon as possible.

Wrap Up

Every driver strives for a simple start-up along with a pleasant driving experience. For continuous smooth performance, every vehicle requires appropriate tuning and occasional checkups. Because modern automobiles are mainly computer-driven, most of the vehicle’s broken bits and faults can be detected through a diagnostic computer scan.

Engine surging is a typical issue with automobiles. It might be an indication of a problem with the electronic components or wiring in an electric vehicle. When it comes to electrical problems, replacement is always the preferable option. However, there may be different options when mechanical parts are concerned.

Don’t make hasty decisions on changing your vehicle’s components. Allow an expert mechanic to direct your efforts.

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