The secondary-air pump pulls in outside air and injects it downstream of the exhaust valves, into the exhaust manifold. If the air is taken straight from the engine compartment rather than the intake system, there is a separate integrated air filter.
Between the secondary-air pump and the exhaust manifold, secondary-air valves are installed. Different variations are used. The secondary-air non-return valve prevents secondary-air pump damage by preventing exhaust gas, condensate, or pressure peaks in the exhaust system (such as misfiring). Only secondary air is directed to the exhaust manifold during the cold starting phase thanks to the secondary-air shut-off valve. Secondary-air valves can be opened in response to the pressure of the secondary-air pump or by a vacuum that is controlled by a solenoid switching valve.
The shut-off and non-return functions are integrated in a single “secondary-air valve” with more current versions.
The solenoid secondary-air valve is the most recent innovation and has faster opening and shutting times than pneumatically actuated valves. This type of valve is less prone to blockage by soot or dirt due to increased actuation forces.
A pressure sensor built into the solenoid secondary-air valve may be used for on-board diagnosis (OBD) monitoring.
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EGR and secondary air pumps
Does your BMW’s secondary air intake (SAI) system have a fault code or check engine light? It’s not just you! On BMWs, the secondary air pump and air pump valve are highly susceptible to failure. “Secondary Air System Flow Too Low” is a frequent error code for air pump problems (an F5 or F6 code on some BMWs). This can be brought on by a malfunctioning secondary air pump (aux pump) or the auxiliary air valve, which is located on the exhaust manifold and regulates air flow. You won’t be able to pass emissions testing if the pump or the valve malfunction. Thankfully, this is an easy DIY fix, and BimmerWorld has the parts for most BMWs.
The item is incompatible with your BMW!
Genuine BMW Secondary Air Pump for 2000-2003 E53 X5 3.0i is how this component is described on the BMW website under part number 11721437700 (11 72 1 437 700). Due to their connection to emissions, these pumps are sometimes known as smog pumps or supplemental air pumps.
Do your secondary air injection pump’s fault codes and check engine light come on? During cold starts, the secondary air pump, which is an emissions pump, injects new air into the exhaust. This aids in fuel combustion in a cold engine, and when the pump operates, it makes a small vacuum cleaner noise under the hood. The emissions control computer reports a fault when this pump malfunctions, preventing the pump from cycling and turning on the check engine light. You will fail an emissions test as a result, and you might not be able to pass a state emissions inspection either.
A two-year warranty is included with this genuine BMW air pump. Although purchasing a Genuine component will typically cost more than purchasing an OEM or aftermarket brand, you can be sure that it will fit, function, and last as intended by BMW. Additionally, it will include the most recent design, taking into account any modifications or changes that an aftermarket brand ordinarily might overlook.
We suggest calling us at 877-639-9648 if you have any inquiries, want to learn more about BMW fitment, or need help from one of our BMW specialists.
Megalocnus
It’s intriguing that BMW made changes to the secondary air injection system’s design while the E46 was still being manufactured. On cold starts, the early models (like my car) have a basic air pump that simply blasts air into the exhaust manifold at a consistent pace for roughly 90 seconds. Even before the catalytic converters are warmed up, this enormous abundance of oxygen aids in the burning of the partially burned fuel that is exhausted from the cold engine. Of course, this also generates more heat, which soon raises the cats’ body temperatures to a comfortable level.
However, too much oxygen in excess can be harmful to the pipes and other equipment. The secondary MAF, which measures how much air is being pumped into the exhaust, is a feature of the later E46 vehicles. This enables management of the secondary air pump output to prevent too lean exhaust conditions.
What location is the secondary air pump in?
Usually found on the engine or at the very least in the engine bay, the secondary air injection pump. Although sometimes it is hidden deep inside the engine room, most of the time you can see it fitted on the engine.
Search for something similar to the image above or below to find it. Follow this hose as it leads to the intake.
What function does a supplementary air pump serve?
Modern cars are equipped with a ton of high-tech parts, many of which are designed to lessen the carbon footprint of the vehicle.
Naturally, this was required by the introduction of new, extremely strict emissions rules in the 1970s and 1980s. Automobile manufacturers were compelled to comply by the prospect of severe fines.
A secondary air injection pump is one such emissions-related part that you may or may not be familiar with. Immediately after starting your car, this specialized device adds airflow to the exhaust system in an effort to further reduce toxic emissions.
The secondary air injection pump in a car is susceptible to eventual failure due to aging and natural wear and tear, just like any mechanical part.
This pump frequently fails along with a variety of symptoms, many of which have varying degrees of seriousness. When trying to identify the problem at hand, it can help to be aware of each of these signs.
Continue reading to discover more about the signs and symptoms of a failing secondary air injection pump, as well as the costs involved in fixing such problems.
What results in the failure of a backup air pump?
The system failing is typically caused most frequently by a faulty pump. Moisture intrusion can result in damage and the pump seizing as a result. The pump may malfunction due to faulty ground and voltage supplies. The failure or malfunction of the control or combination valve, which results in the failure of the secondary air system, can also be brought on by clogged or leaky lines.
Is it possible to drive with a damaged secondary air pump?
In order for cars to meet government emissions regulations, the system is essential. Thus, according to the law, you require a supplementary air injection system. Which raises the question: Is a secondary air injection system necessary for a car to function? In a strict sense, no, it doesn’t
How much does a secondary air pump cost to replace?
Any enthusiast for automobiles is aware of the benefits of a good air injection system for extending the life and fuel efficiency of an engine. Making sure your secondary air injection system is functioning properly is a crucial part of maintaining your car in good shape. If it breaks, you should replace it as soon as you can.
A secondary air injection system will cost you about $450 to repair in total. The cost of labor and the cost of parts are both included in this. Labor is often another $150-$200, with new parts costing roughly $250. By upgrading your air injection system yourself, you might save money on labor costs if you have the necessary skills.
The prices of fixing your secondary air injection system depend on a number of unique factors. Therefore, we created this extensive guide that covers both the fundamental prices and costs for particular models. We will also discuss the elements that influence repair costs.
How can I tell whether my backup air pump is operating properly?
Failure of the backup air pump following a cold start? Is the engine compartment emitting a burnt smell? Are the secondary air pump’s electrical contacts burned? Overload may have caused the secondary air pump to malfunction. About how this occurs, read this.
Potential grievances
- After a cold start, the secondary air pump does not operate.
- The odor of char in the engine section
- melting traces on the secondary air pump’s electrical connections
- “Malfunction” P0410
These circumstances suggest that overloading caused the secondary air pump to malfunction.
Potential reasons:
The relay that controls the secondary air pump is stuck. The secondary air pump was powered on for an excessively long duration as a result. The auxiliary air pump should only be running for 90 to 120 seconds during a cold start. The auxiliary air pump is not intended to be used continuously.
When starting a vehicle with a cold engine:
When the car’s engine is warm:
If the secondary air pump’s power source is working properly but the secondary air pump makes a scraping, whistling, or scratching noise when running or doesn’t run at all, the secondary air pump needs to be replaced.
All other secondary air system parts ought to be examined in such circumstances.
After a cold start of the engine, the secondary air pump must run for approximately 90 to 120 seconds.
The definition of secondary air injection system
Secondary air injection, also referred to as air injection, is a method for reducing vehicle emissions that was first used in 1966. It involves injecting fresh air into the exhaust stream to promote a more complete secondary combustion of exhaust gases.
What occurs if your air pump fails?
Yes, you can continue to drive without a backup air pump. However, your car must be at least 15 years old in order to do this. Except for California, where these regulations only apply when changing ownership or traveling across state lines with new registration requirements, it must pass the yearly tailpipe test required by law in the US (which means not every vehicle will meet all requirements).
Lack of an air pump prevents oxygen from entering the exhaust system, which prevents gasoline from being burned. Extremely high levels of carbon monoxide are released from the exhaust as a result, and the increased heat may also endanger other engine parts.
Can a misfire be caused by a secondary air injection pump?
A Misfire From a Secondary Air Pump? Yes, a malfunctioning secondary air system frequently manifests as a misfire. Your car will have too much gasoline and not enough oxygen if the pump isn’t functioning properly, which frequently causes a misfire.
How is a secondary air injection system cleaned?
The main approach is to clean the ports from the bottom up until air flows freely through the channels after adding solvent and compressed air to the SAI system on top of the engine.
How is a secondary air check valve tested?
secondary air pump that is noisy? Why do cold engines experience speed variations? What is the root cause of P0410 and P0411 diagnostic problem codes? Find out why it’s important to examine the secondary air valve and the actuating electric switchover valve here.
In automobiles with a supplemental air system, the following client complaints may happen during the cold-running phase:
- noises from the secondary air pump (SLP).
- SLP is ineffective.
- failure of the SLP repeatedly after a short running duration
- variations in engine revs when it’s cold The OBD error codes P0410 and P0411 are examples.
The secondary air pump may continue to malfunction because the cause of this damage is still inside the car. The electrical reversing valve and the secondary air valve must both be checked for leaks while replacing the secondary air pump.
It is simple and quick to inspect the secondary air valve:
- On the secondary air non-return valve that connects to the secondary air pump, loosen the connecting hose. View inspection point “P” on the illustration above.
- The nonreturn valve needs to be replaced if there are deposits on this side of the valve (finger test, see Fig. 1). The secondary air pump may already be damaged in that situation.
- The secondary air pump should be examined and replaced if necessary.
Exhaust gas condensate in the secondary air pump is usually often to blame for this damage. During repairs, it’s common to merely swap out the secondary air pump.
The secondary air system is not complete without secondary air valves. They are installed between the exhaust manifold and the secondary air pump (1). They stop exhaust gas or condensate from getting into the secondary air pump as well as pressure peaks in the exhaust flow from harming the secondary air system. Secondary air valves can be designed in a variety of ways:
Switch-off non-return valves (3) typically function under vacuum. Later designs (starting around 1998) are opened by the secondary air’s pressure. Pneumatic control via an electrical reversing valve is eliminated as a result (2). The secondary airflow’s pressure causes the secondary-air non-return valves (#5) to open.